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Biodefense
Reference Library
Foreign
Animal and Zoonotic Disease Center
Zoonotic
Disease Online Course
Presented
by
Stephen M.
Apatow, Director
of Research and Development
Humanitarian
Resource Institute
Biodefense Reference Library
Foreign
Animal and Zoonotic Disease Center
[Vitae][Email]
ZOONOTIC
DISEASES
BACTERIAL
BRUCELLOSIS
U.S.
Centers for Disease Control and Prevention: Division of Bacterial and
Mycotic
Diseases
Brucellosis:
General
Information | Technical
Information | Additional
Information
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(In
humans: Mediterranean fever, undulant fever, Malta fever. In animals:
contagious
abortion, epizootic abortion, Bang's disease)
AGENT:
Brucella
abortus: cattle, sheep Brucella canis: dogs Brucella melitensis: sheep,
goats Brucella suis: swine.
RESERVOIR
AND INCIDENCE
Of the
above species, Brucella canis is most likely zoonotic agent in the lab
animal facility due to the extensive use of random source and lab bred
dogs, in contrast to use of large domestic animals. Prevalence: 1 to
10%
in dogs, throughout the U.S. B. canis is well adapted to dogs, and is
not
the subject of a large scale eradication program in the general dog
population,
as Brucella has been in other animals. Human brucellosis due to B.
canis
is uncommon but can be acquired from dogs; most cases resulted from
contact
with aborting bitches. In 1988, the CDC noted 96 cases of brucellosis
reported
in the U.S.: 22 from Texas and 20 from Calif.
TRANSMISSION:
Ingestion
of unpasteurized milk Lab accidents Poorly defined transmission cycle
in
zoonotic diseases: contact with infected animals especially aborted
fetuses,
fluids or membranes, or urine. Possibly airborne.
DISEASE
IN ANIMALS:
Abortions
are followed by immunity, though carrier state persists especially with
secretions from the udder. infertility, testicular abnormalities, poor
semen quality in dogs. inapparent infection may be common, as indicated
by seropositivity.
DISEASE
IN MAN:
Lymphadenopathy,
splenomegaly, fever, headache, chills, orchitis, weakness, nausea,
weight
loss. The chronic form may assume an undulant nature, with periods of
normal
temperature between acute attacks; symptoms may persist for years,
either
continuously or intermittently. Antibiotics can effect a cure within
one
year in about 80% of cases. Case fatality if untreated is less than
2%.
DIAGNOSIS:
Rapid
slide agglutination test is available. Blood culture and additional
serologic
tests used to confirm slide test results.
TREATMENT:
Single-drug
regimens are not recommended because the relapse rate may be as high as
50%. Combination regimens of two or three drugs are more effective.
Either
(1) doxycycline plus rifampin or streptomycin (or both) (2)
trimethoprim-sulfamethoxazole
plus rifampin or streptomycin (or both) are effective in doses for 21
days.
Longer courses of therapy may be required to cure relapses,
osteomyelitis,
or meningitis.
PREVENTION\CONTROL:
Quarantine
and test Disposable gloves Chlorine, organic iodine, quaternary
ammonium
compounds are rapid bactericidal agents.
SALMONELLOSIS
U.S.
Centers for Disease Control and Prevention: Division of Bacterial and
Mycotic
Diseases
Salmonellosis:
General
Information | Technical
Information | Additional
Information
Office
International des Epizooties
Salmonellosis:
Manual of standards Diagnostic Tests and Vaccines 2000
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Salmonella
food poisoning, enteric paratyphosis) A common bacterial cause of
food-poisoning
worldwide. Over 1800 food-poisoning serotypes of salmonella (bacterium)
exist. The prevalence of individual serotypes constantly changes. In
the
U.S., 5 million cases are diagnosed annually. S. typhi, the cause of
Typhoid
Fever, rarely occurs in the U.S. and is not discussed here.
RESERVOIR
AND MODE OF
TRANSMISSION:
Salmonellas
are common commensals of all animals and birds and are excreted in
feces.
Host-adapted strains may cause serious illness (e.g., S. dublin in
cattle,
S. pullorum in chickens), but most human food-poisoning salmonellas do
not cause clinical signs in animals. The main reservoirs for human
infection
are poultry, cattle, sheep and pigs. Infection in animals is maintained
by recycling slaughterhouse waste as animal feed, fecal oral spread and
fecal contamination of hatching eggs. Transmission occurs when
organisms,
introduced into the kitchen in poultry carcasses, meat or unpasteurized
milk, multiply in food owing to inadequate cooking, cross-contamination
of cooked foods and inadequate storage. Person-to-person spread is
common
in institutions such as hospitals. The organism inhabits the intestinal
tract of many animals including birds, cattle, sheep, pigs, lab.
animals
(rats, mice, hamsters, guinea pigs, nonhuman primates) and humans.
Salmonella
occurs worldwide. *The house mouse may also be a reservoir of the
infection
and may play a role in human and animal salmonellosis. Humans, rarely,
and animals may be carriers and asymptomatic shedders of the organism.
*Salmonella prevalence in the U.S. canine population may be 10% or
more.
*Prevalence data from 8 studies conducted worldwide indicated that a
wide
range (0.6-27%) of cats were culture-positive for Salmonella.
*Salmonella
carriers in newly imported Rhesus and Cynomolgus monkeys exceeded 20%
in
some shipments. *Birds, reptiles, and turtles are especially dangerous
sources of Salmonellosis. 94% of all reptiles harbor Salmonella.
Turtles
alone in 1970 may have caused 280,000 human cases of Salmonellosis. *In
1975 the FDA ruled it illegal to sell a. Viable Turtle eggs b. Live
turtles
with a carapace length < 10.2cm (4 inches) c. Exceptions -
Educational
& scientific institutions and marine turtles. d. Marine turtles
have
not been shown to be a reservoir of Salmonella
TRANSMISSION:
Indirect
transmission via contaminated food and water are the most common
sources
but transmission may also be by direct contact. It is a common
contaminant
of sewage. Found in many environmental water sources. Environmental
contamination
continues to be a potential source of infection for lab animals and
secondarily
for personnel handling those animals. *Animal feed containing animal by
products continues to be a source of Salmonella contamination,
especially
if the diets consist of raw meal and have not undergone the pelleting
process.
INCUBATION
PERIOD:
Humans.
12-72 hours. Animals. 1-5 days.
CLINICAL
FEATURES:
Humans.The
presence and severity of symptoms depends on the infecting dose.
Typically
there is watery diarrhoea for about ten days, possibly leading to
dehydration,
with abdominal pain and low-grade fever. Septicemia and abscess
formation
are rare. Animals. Subclinical infection is common and many animals may
be intermittent or persistent carriers. However, cows may suffer with
fever,
diarrhoea and abortion. Calves undergo epizootic outbreaks of diarrhoea
with high mortality. In pigs, fever and diarrhoea are less common than
in cattle. Infected sheep, goats and poultry usually show no signs of
infection.
PATHOLOGY:
Humans.
Enteritis is a feature. Extraintestinal infection may cause abscesses.
Animals. Penetration of the infection into the mucosa is followed by
inflammation,
especially ileitis, progressing to inflamed mesenteric lymph nodes in
the
mesentery, possibly progressing to septicemia and pneumonia especially
in calves. Dehydration and rapid loss of weight are due to stimulation
of chloride excretion and inhibition of sodium absorption. Abortion in
cattle is caused by massive proliferation of salmonella in the placenta
leading to placental necrosis.
DIAGNOSIS:
Humans.
Isolate salmonella from feces and suspected foods using selective media
followed by serotyping and, if appropriate, phage typing. Animals.
Culture
feces, postmortem tissues and foods of animal origin. Serological tests
are of limited value as many noninfected animals have titers from past
infections. Humans. Usually only a self-limiting illness occurs. Deaths
from dehydration or septicemia are rare and occur usually in infants,
or
debilitated or elderly patients. Animals.There is abortion in cattle
and
endometritis with temporary infertility. In calves, dehydration and
septicemia
may lead to death.
PREVENTION:
Humans.
Educate food handlers in good kitchen hygiene. Ensure thorough cooking
of meat, refrigerate cooked foods and prevent cross-contamination.
Pasteurize
all milk. Ensure personal hygiene. Reduce contamination of poultry
carcasses
at abattoirs. Irradiation of meat and other foods before purchase will
reduce contamination. Animals. This is difficult and often impractical
because there are many sources of infection. Principles of control
include
the following: maintain closed herds and flocks; keep animals in small
groups; purchase replacements direct from the farm of origin; avoid
mixing
animals from different sources; sterilize ingredients of animal feed;
provide
mains drinking water for grazing livestock; prevent access of wild
birds
and rodents to animal houses; completely destock animals and thoroughly
cleanse and disinfect housing between batches; monitor poultry breeding
stock and remove excreters; disinfect hatching eggs and fumigate
incubators.
TREATMENT:
Humans.
Treatment of uncomplicated enterocolitis is symptomatic only. Young,
malnourished,
or immunocompromised infants, severely ill patients, those with sickle
cell disease, and those with suspected bacteremia should be treated for
3-5 days with trimethoprim-sulfamethoxazole (one double-strength tablet
twice a day), ampicillin (100 mg/kg IV or orally), or ciprofloxacin
9750
mg twice daily). Animals. Treatment with antibiotics and sulfonamides
immediately
diarrhoea and fever occur reduces mortality but is contraindicated in
healthy
carriers in which treatment may prolong the carrier state.
VACCINATION:
Humans.
None. Animals. Vaccines are available against S. dublin and S.
typhimurium
in calves. A live vaccine prepared from a rough strain of S. dublin
gives
good protection in calves against both S. dublin and S.
typhimurium.
LEGISLATION:
Humans.
The disease is notifiable specifically in the USA, Australia, New
Zealand
and several European countries, or as food-poisoning as in the UK.
Animals.
Notification of infection in food animals is obligatory in some
countries,
including the UK, with statutory sampling of animal protein for animal
feed. Heat treatment of waste food applies in the UK. A slaughter
policy
is claimed in Luxembourg, Germany and Czechoslovakia.
SHIGELLOSIS
U.S.
Centers for Disease Control and Prevention: Division of Bacterial and
Mycotic
Diseases
Shigellosis:
General
Information | Technical
Information | Additional
Information
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
SYNONYM:
Bacillary
dysentery.
ETIOLOGY:
The type
species is Shigella dysenteriae, other agents are S. flexneri, S.
boydii,
and S. sonnei. The first three species are subdivided into
serotypes.
GEOGRAPHIC
DISTRIBUTION:
Worldwide.
THE
DISEASE IN MAN:
It is
seen most often in preschool-age children. A new serotype introduced
into
tropical areas where the population is undernourished provokes disease
in all age groups, particularly children, the elderly, and debilitated
individuals. Generally, the incubation period is less than 4 days. The
disease begins with fever and abdominal pains, followed by diarrhea and
dehydration for 1 to 3 days. A second phase of the symptomatology can
last
for several weeks. The main symptom is tenesmus; in serious cases,
stools
contain blood, mucus, and pus. The symptomatology is usually variable.
In many countries, strains of Shigella resistant to sulfonamides and to
several antibiotics have been observed.
THE
DISEASE IN ANIMALS:
A clinical
picture similar to that in man occurs in monkeys.
SOURCE
OF INFECTION
AND MODE OF TRANSMISSION:
The principal
reservoir of the infection for man is other humans that are sick or
carriers.
The sources of the infection are feces and contaminated objects. The
most
common mode of transmission is the fecal-oral route. Outbreaks
comprising
numerous cases have had their origin in a common source of infection,
such
as foods contaminated by hands or feces of carrier individuals.
Insects,
particularly flies, can also play a role as mechanical vectors.
Bacillary
dysentery is a serious disease with high mortality in nonhuman primates
in captivity, but there is doubt that monkeys can harbor the etiologic
agent in their natural habitat. Monkeys probably contract the infection
by contact with infected humans. The infection spreads rapidly in
nonhuman
primate colonies because the monkeys defecate on the cage floor and
also
often throw their food there.
ROLE
OF ANIMALS IN THE
EPIDEMIOLOGY OF THE DISEASE:
Of little
significance. Cases of human bacillary dysentery contracted from
nonhuman
primates are known. The victims are mainly children. In highly endemic
areas, dogs may shed Shigella temporarily. The etiologic agent has also
been isolated from horses, bats, and rattlesnakes. Nevertheless,
animals
other than nonhuman primates play an insignificant role.
DIAGNOSIS:
Definitive
diagnosis depends on isolation of the etiologic agent by culture of
fecal
material on selective media. Serologic identification and typing are
important
from the epidemiologic viewpoint.
TREATMENT:
In humans,
treatment of dehydration and hypotension is lifesaving in severe cases.
The current antimicrobial treatment of choice is
trimethoprim-sulfamethoxazole
(one double-strength tablet twice a day), or ciprofloxacin (750 mg
twice
a day; contraindicated in children and pregnant women). Parental
hydration
and correction of acidosis and electrolyte disturbances are of primary
importance.Antispasmodics (e.g., tincture of belladonna) are helpful
when
cramps are severe. Drugs that inhibit intestinal peristalsis
(paregoric,
diphenoxylate with atropine) may ameliorate symptoms but prolong fever,
diarrhea, and excretion of Shigella in feces. Appropriate precautions
should
be taken both in the hospital and in the home to limit spread of
infection.
CONTROL:
In man,
control methods include a) environmental hygiene, especially disposal
of
human waste and provision for potable water; b) personal hygiene; c)
education
of the public and of food handlers about the sources of infection and
methods
of transmission; d) sanitary supervision of the production,
preparation,
and preservation of foods: e) control of flies; f) reporting and
isolation
of cases and sanitary disposal of feces; and g) search for contacts and
the source of infection. A live, streptomycin-dependent vaccine,
administered
orally in three or four doses has given good protection against the
clinical
disease for 6 to 12 months. Its use is indicated in institutions where
shigellosis is endemic. Indiscriminate use of antibiotics must be
avoided
tn order to prevent the emergence of multiresistant strains and to
ensure
that these medications remain available for use in severe cases. In
animals,
control consists of a) isolation and treatment of sick or carrier
monkeys:
b) careful cleaning and sterilization of cages; c) prevention of
crowding
in cages: and d) prompt disposal of wastes and control of insects.
YERSINIA
U.S.
Centers for Disease Control and Prevention: Division of Bacterial and
Mycotic
Diseases
Yersinia
enterocolitica: General
Information | Technical Information | Additional Information
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
Laboratory
animals are susceptible to three Yersinia species that are potentially
zoonotic:
AGENT:
Gram negative,
non spore forming rods.
1. YERSINIA
PSEUDOTUBERCULOSIS AND ENTEROCOLITICA
(Pseudotuberculosis)
RESERVOIR
AND INCIDENCE
Ubiquitous
in nature, isolated from dust, soil, water, milk. Natural infections
occur
in man, birds, rodents, rabbits , guinea pigs, mice, cats, nonhuman
primates,
sheep, swine, goats.
TRANSMISSION:
Direct
contact, or fecal contaminated food or water cause most transmission
from
animals to man. Human cases of have been reported in association with
disease
in household pets, particularly sick puppies and kittens. The most
important
source of Y. enterocolitica infection may be pork, as the pharynx of
pigs
may be heavily colonized.
DISEASE
IN ANIMALS:
Guinea
pigs, rabbits, and hamsters exhibit poor condition and enlarged lymph
nodes.
Subacute clinical signs are common, with diarrhea and weight loss,
possibly
death within 2 weeks to 3 months. Chinchillas are very susceptible to
infection
with Y. enterocolitica. In sheep, abortions, epididymitis and orchitis
occur with high mortality. In cattle, abortion and pneumonia occur.
Nonhuman
primates exhibit an ulcerative colitis. Histopathological lesions
include
acute inflammation of the terminal ileum with mesenteric lymphadenitis
occurs. Sometimes abscesses develop in the liver, spleen, and lungs.
Usually
self-limiting, but there is a fatality rate of 5-7%.
DISEASE
IN MAN:
Acute
watery diarrhea, mesenteric lymphadenitis which can be confused with
appendicitis,
fever, headache, pharyngitis, anorexia, vomiting erythema nodosum (in
about
10% of adults), post-infectious arthritis, iritis, cutaneous
ulceration,
hepatosplenic abscesses, osteomyelitis and septicemia.
DIAGNOSIS:
Fecal
culture using cold enrichment technique. Serologic diagnosis can be
made
by an agglutination test or by ELISA.
TREATMENT:
Usually
resistant to penicillin and its derivatives. Agents of choice are the
aminoglycosides
and cotrimoxazole. Both are usually sensitive to the
tetracyclines.
PREVENTION/CONTROL:
Control
rodents and prevent contamination of food and water by rodents and
birds.
Pasteurize milk. Cook pork thoroughly. Personal hygiene is
important.
2. YERSINIA
PESTIS
(Plague,
Pest, black death, pestilential fever) The second pandemic of plague,
known
then as the "Black Death," originated in Mesopotamia about the middle
of
the 11th century, attained its height in the 14th century and did not
disappear
until the close of the 17th century. It is thought that the Crusaders,
returning from the Holy Land in the 12th and 13th centuries, were
instrumental
in hastening the spread of the disease. Again the land along trade
routes
was primarily involved and from them the infections spread east, west,
and north. During the course of the disease, 25,000,000 people
perished,
a fourth of the population of the world.
AGENT:
A gram
negative coccobacillus.
RESERVOIR
AND INCIDENCE
Endemic
in wild rodents in Southwestern U.S., as well as in Africa and Asia.
Most
important reservoirs worldwide are the domestic rat, Rattus rattus, and
the urban rat, Rattus norvegicus. Human infections have increased since
1965 and usually result from contact with infected fleas or rodents.
The
disease is also associated with cats, goats, camels, rabbits, dogs and
coyotes. Dogs and cats may serve as passive transporters of infected
rodent
fleas into the home or laboratory.
TRANSMISSION:
Contact
with infected rodent fleas or rodents. Fleas may remain infected for
months.
Note: a protein secreted by the Yersinia is a coagulase that causes
blood
ingested by the flea to clot in the proventriculus. The bacillus
proliferates
in the proventriculus, and thousands of organisms are regurgitated by
obstructed
fleas and inoculated intradermally into the skin. This coagulase is
inactive
at high temperatures and is thought to explain the cessation of plague
transmission during very hot weather. Pulmonary form spread by airborne
or droplet infection. Human infections from non-rodent species usually
result from direct contact with infected tissues, by scratch or bite
injuries,
and handling of infected animals. Several recent reports have detailed
human plague associated with exposure to domestic cats. Exposure can be
from inhalation of respiratory secretions of cats with pneumonic plague
or by contaminating mucous membranes or skin wounds with secretins or
exudates.
DISEASE
IN ANIMALS:
dogs usually
have a brief self-limiting illness cats usually exhibit severe and
often
fatal infection, with fever, lymphadenopathy, hemorrhagic pneumonia,
and
encephalitis. rodents may carry the disease asymptomatically or develop
fatal disease. infected rats and squirrels frequently die unless they
are
from an enzootic area and have acquired immunity.
DISEASE
IN MAN:
Incubation
period 2 to 6 days. In humans the disease is called Bubonic,
Septicemic,
or Pneumonic plague depending on the pattern of distribution of the
infection.
Bubonic is the most common form causing fever and swollen, tender lymph
nodes (called Buboes). Pneumonic plague is systemic plague with lung
involvement.
Mortality may exceed 50%. Plague is also called the "black death"
because
disseminated intravascular coagulation takes place and areas of skin
undergo
necrosis.
DIAGNOSIS:
Impression
smears of aspirates or blood stained with gram or Giemsa. Organisms
have
a typical "safety pin" appearance culture of the organisms can be
performed,
by reference lab FA of smear is confirmatory. Serology via Complement
fixation,
passive hemagglutination, and immunofluorescence (IFA)
TREATMENT:
Streptomycin
with tetracycline or chloramphenicol.
PREVENTION\CONTROL:
Wild rodents
should be controlled and fleas should be eliminated. It is important to
control rodents and fleas for outdoor housed animals. Sentinel animal
programs
used in endemic areas. Endemic areas of the U.S. include California,
Nevada,
Arizona, and New Mexico. Masks gowns, and gloves should be worn when
handling
cats suspected to be infected and all contaminated surfaces
disinfected.
Notify Health Department of suspected cases Vaccines available for high
risk personnel.
TUBERCULOSIS
(Consumption)
AGENT,
RESERVOIR AND
INCIDENCE
TB is
caused by the gram positive, acid fast, aerobic, bacillus of the
Mycobacterium
genera. The most common species of mycobacteria are: 1. M. bovis
(cattle,
dogs, swine) 2. M. avium (birds, swine, sheep) 3. M. tuberculosis (man,
nonhuman primates, cattle, dogs, swine, psitticines). 4. M. marinum,
fortuitum,
platypolcitis (fish) Note: Atypical mycobacterium, M. scrofulaceum, M.
kansasii, and M. intracellulare have been reported in NHP's and are
also
present in soil and water. They can cause pulmonary disease refractory
to treatment in man, and are most often seen in immunocompromised
people.
Specific reagents can be used to skin test for these bacteria. TB
continues
to be a major cause of morbidity and mortality throughout the world.
One
billion people are infected with the tubercle bacillus, and there are 8
million new cases and 3 million deaths annually. Cases of active
tuberculosis
are increasing in the United States after years of decline. A
provisional
total of 23,720 cases was reported by the end of 1990. Case rates
increased
4.4 percent between 1988 and 1989, and perhaps another 1 percent in
1990.
Overall rate was 9.5 per 100,000 in 1989, with the Middle Atlantic and
Pacific regions reporting the highest rates, 36 percent and 34 percent,
respectively, above the U.S. total. The lowest rates were in the West,
North, Central, and Mountain regions. Rates continue to be higher among
urbanites, minorities, the poor, the homeless, substance abusers and
persons
infected with HIV. All three types are capable of causing disease in
man
although M. tuberculosis (variety hominis) is by far the most common.
Nonhuman
primates can carry all three types but most infections are caused by M.
tuberculosis variety hominis. While most nonhuman primates are capable
of contracting TB, Old World species appear to be more susceptible to
the
disease than New World species and great apes. Most cases of TB in
monkeys
are thought to arise from human contact. Animals may be imported from
areas
of the world where the incidence of the disease is high and where
contact
between humans and simians is frequent. In close confinement the
disease
can spread rapidly.
TRANSMISSION:
Mycobacterium
bacilli are transmitted from infected animals or infected tissue
primarily
via the aerosol route. May also be contracted via ingestion or
cutaneous
inoculation of the bacilli. Personnel caring for infected animals as
well
as those performing necropsies on infected animals are at risk for
contracting
the disease. Exposure to dusty bedding of infected animals, coughing of
infected animals, and aerosolization of the organism during sanitation
procedures may also be sources of the disease in the lab environment.
Once
within the body the organism may spread throughout the lungs,
lymphatics,
blood vascular system, and many visceral organs.
DISEASE
IN NONHUMAN
PRIMATES:
The signs
of TB may be insidious with only slight behavioral changes noticed,
followed
by anorexia and lethargy. Often animals die suddenly while appearing to
be in good condition. Other signs which might be seen include diarrhea,
suppuration of lymph nodes, ulceration of the skin, and palpable
splenomegaly
and hepatomegaly. The organ of predilection is the lung but lesions may
also be seen in the pleura, intestines, lymph nodes, liver, kidney,
spleen,
and peritoneum. Under the surface of these tissues are yellowish-white
to gray nodules filled with caseous material which may rupture and
produce
cavitation. Although skeletal involvement in primates is rare,
tuberculosis
of the spine may cause paralysis of the hindlimbs (Pott's
disease).
DISEASE
IN FISH:
In infected
fish, granulomatous lesions are usually observed.
DISEASE
IN MAN:
In humans
the clinical signs depend on the organ system involved. The most
familiar
signs related to pulmonary TB are cough, sputum production, and
hemoptysis.
The patient may be asymptomatic for years. General signs may include
anorexia,
weight loss, lassitude, fatigue, fever, chills and cachexia. Skin
lesions
are characterized by ulcers or by papular lesions progressing to dark
suppurative
lesions. TB may affect virtually every other organ system with signs or
symptoms relating to the individual system. Miliary TB is most often
seen
in the very young and old people.
DIAGNOSIS:
The diagnosis
of TB is often difficult. Four tests are commonly used for presumptive
diagnosis: 1. Intradermal TB test - Mammalian tuberculin 2. Radiography
3. Acid fast stained sputum smear 4. ELISA Confirmation by culture,
histopath,
or animal inoculation.
TREATMENT:
Regimens
currently accepted in the USA include isoniazid combined with rifampin,
with or without pyrazinamide.
PREVENTION\CONTROL:
Multifaceted
and includes: personnel education wearing of protective clothing when
handling
nonhuman primates a regular health surveillance program for humans and
nonhuman primates isolation and quarantine of suspect animals rapid
euthanasia
and careful disposal of infected animals Vaccine - A vaccine, BCG, is
available
(Bacille Calmette-Guerin, strain of M. Bovis) a. Used in humans quite
often
in G. Britain b. Used in high risk groups c. Effective, but it causes
the
patient to have a positive TB test. Personnel working with NHP's who
convert
to a positive skin test should be referred for appropriate medical
treatment
and follow up and should not work with animals until shown to be
noninfectious.
LEPROSY
U.S.
Centers for Disease Control and Prevention: Division of Bacterial and
Mycotic
Diseases
Leprosy:
See:
Hansen's
Disease
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
SYNONYM:
Hansen's
disease.
ETIOLOGY:
Mycobacterium
leprae, a polymorphic acid-alcohol-fast bacillus. M. leprae is hard to
distinguish from other unculturable mycobacteria naturally infecting
animals.
The failure of attempts to culture M. leprae in vitro constitutes a
great
barrier to better determining its biochemical characteristics for
identification
purposes as well as for therapeutic and immunologic studies. In part,
this
difficulty has been overcome, first, by in vivo culture on mouse foot
pads
and, lately, by the discovery that the leprosy organism can infect the
nine-banded armadillo (Dasypus novemcinctus). At present, the latter
serves
as a model for lepromatous leprosy and provides a large number of
bacilli
for research.
OCCURRENCE
IN MAN:
An estimated
12 million people are affected by leprosy. The highest prevalence is in
tropical and subtropical regions of Asia, Africa, Latin America, and
Oceania.
Leprosy is very prevalent in India, Southeast Asia, the Philippines,
Korea,
southern China, Papua New Guinea, and some pacific islands. Ninety
percent
of the cases reported in the Americas come from five countries:
Argentina,
Brazil, Colombia, Mexico, and Venezuela. Chile is the only South
American
country free of the infection. In the United States 2,500 cases are
known,
most of them in immigrants. Autochthonous cases arise in Hawaii, Puerto
Rico, Texas, and Louisiana. The infection's prevalence is related to
the
socioeconomic level of the population. The fact that the disease has
practically
disappeared in Europe is attributed to the improved standard of living
there. The proportion of total leprosy cases represented by lepromatous
leprosy (see The Disease in Man) varies with the region. In Asia and
the
Americas this form makes up between 25 and 65% of all cases, while in
Africa
it accounts for only 6 to 20%.
THE
DISEASE IN MAN:
The incubation
period is usually 3 to 5 years, but it can vary from 6 months to 10
years
or more. Clinical forms of leprosy cover a wide spectrum, ranging from
mild self-healing lesions to a progressive and destructive chronic
disease.
The polar form at one end of the spectrum is tuberculoid leprosy, and
at
the other, lepromatous leprosy. Intermediate forms are also found.
Tuberculoid
leprosy is characterized by localized lesions of the skin and nerves,
often
asymptomatic. Basically, the lesions consist of a granulomatous,
paucibacillary,
inflammatory process. The bacilli are difficult to detect, and can be
observed
most frequently in the nerve endings of the skin. This form results
from
active destruction of the bacilli by the cellular immunity of the
patient.
On the other hand, serum antibody titers are generally low. Nerve
destruction
causes lowered conduction; heat sensibility is the most affected,
tactile
sensibility less so. Trophic and autonomic changes are common,
especially
ulcers on the sole and mutilation of body members. Lepromatous leprosy
is characterized by numerous symmetrical skin lesions consisting of
macules
and diffuse infiltrations, plaques, and nodules of varying sizes
(lepromas).
There is involvement of the mucosa of the upper respiratory tract, of
lymph
nodes, liver, spleen, and testicles. Infiltrates are basically
histiocytes
with a few lymphocytes. Cellular immunity is absent (negative reaction
to lepromin) and antibody titers are high. In this form of the disease,
as in the borderline, erythema nodosum leprosum (ENL) often appears.
The
indeterminate form of leprosy has still not been adequately
characterized
from the clinical point of view; it is considered to be the initial
stage
of the disease. The first cutaneous lesions are flat, hypopigmented,
and
have ill-defined borders. If this form is not treated, it may develop
into
tuberculoid, borderline, or lepromatous leprosy. Bacilli are few, and
it
is difficult to confirm their presence. Finally, the borderline form
occupies
a position intermediate between the two polar forms (tuberculoid and
lepromatous),
and shares properties of both; it is unstable and may progress in
either
direction. Destruction of nerve trunks may be extensive. Bacilli are
observed
in scrapings taken from skin lesions. An estimated one-third of
clinical
cases become incapacitated. half of them completely. Nevertheless,
these
proportions are now changing, due to both prevention/control programs
and
early implementation of effective treatments. There is evidence that
inapparent
infection may occur with a certain frequency among persons, especially
family members, in contact with patients.
THE
DISEASE IN ANIMALS:
The disease
in armadillos (Dasypus novemcinctus) is similar to the lepromatous form
in man. Infection in these animals is characterized by macrophage
infiltrates
containing a large number of bacilli. Skin lesions vary from mild to
severe.
The small dermal nerves are invaded by the etiologic agent. Many
bacilli
are seen in the macrophages of the lymph tissue, in the pulp of the
spleen,
and in Kupffer's cells in the liver. M. leprae is known to prefer the
coolish
parts of the human or mouse body. For this reason, armadillos were used
as experimental animals even before natural inaction was confirmed in
them,
since their body temperature is from 30 to 35oC. Experimental
inoculation
of armadillos with human leproma material reproduces the disease,
characterized
by broad dissemination of the agent, and involvement of lymph glands,
liver,
spleen, lungs, bone marrow, meninges, and other issues, in a more
intense
form than is usually observed in man. The disease in the chimpanzee
appeared
as a progressive chronic dermatitis with nodular thickening of the skin
of the ears, eyebrow nose, and lips. Lesions of the nose, skin, and
dermal
nerves contained copious quantities of acid-fast bacteria. The case was
histologically classified as borderline 12 months after the clinical
symptoms
were first observed, and as lepromatous after a later biopsy. In the
case
of the Cercocebus monkey, the initial lesion consisted of nodules on
the
face. Four months later, a massive infiltration and ulceration were
seen
on the face and nodules appeared on the car and the forearms. Sixteen
months
after cutaneous lesions were first observed. The animal began to suffer
deformities and paralysis of the extremities. Histopathologic findings
indicated the subpolar or intermediate lepromatous form. The disease
was
progressive, with neuropathic deformation of feet and hands. It seemed
to regress when specific treatment was administered. The animal
apparently
contracted the disease from a patient with active leprosy. Experimental
infections carried out to date have indicated that these animals may
experience
a spectrum of different forms similar to those in man.
SOURCE
OF INFECTION
AND MODE OF TRANSMISSION:
Man is
the principal reservoir of M. leprae. The method of transmission is
still
not well known due to the extended incubation period. Nevertheless, the
principal source of infection is believed to be lepromatous patients,
in
whom the infection is multibacillary, skin lesions are often ulcerous,
and a great number of bacilli are shed through the nose similarly.
Bacilli
are found in the mouth and pharynx. Consequently, transmission might be
effected by contact with infected skin, especially through wounds or
abrasions,
and by aerosols, as is the case in tuberculosis. Lately, more
importance
has been attributed to aerosol transmission. Oral transmission and
transmission
by hematophagous arthropods are not discounted, but they are assigned
less
epidemiologic importance. Until recently, leprosy was believed to be an
exclusively human disease. But research in recent years has
demonstrated
that the infection and the disease also occur naturally in wild
animals.
Even though some researchers have expressed doubt that the animal
infection
is identical to the human, at present an accumulation of evidence
indicates
that the etiologic agent is the same. The origin of infection in
animals
is unknown. It is believed that armadillos contracted the infection
from
a human source, perhaps from multibacillary patients before the era of
sulfones. In this regard, it should be pointed out that leprosy bacilli
may remain viable for a week in dried nasal secretions and that
armadillos
are in close contact with the soil. The high disease prevalence in some
localities would indicate armadillos can transmit the infection to one
another, either by inhalation or direct contact. Another possible
transmission
vehicle is maternal milk, in which the agent has been detected. It is
difficult
to demonstrate that armadillos are a source infection for man because
of
the long incubation period in humans and the impossibility of excluding
a human source in an endemic area. In Texas, a case of human leprosy
was
attributed to a patient's practice of capturing armadillos and eating
their
meat. Subsequently, another five cases with hand lesions were detected
in natives of the same state who habitually hunted and cleaned
armadillos
but had no known contact with human cases. The prevalence of leprosy in
armadillos in Louisiana and Texas suggests that these animals could
serve
as a reservoir of M. leprae; however, nothing is known about the
frequency
of infection in nonhuman primates and the role they may play in
transmission
of the disease. The sources of the cases of leprosy in these animals
were
probably people with lepromatous leprosy.
DIAGNOSIS:
Laboratory
confirmation of leprosy requires the demonstration of acid-fast bacilli
in scrapings from slit skin smears or the nasal septum. Biopsy of skin
or of a thickened involved nerve also gives a typical histologic
picture.
M. leprae does not grow in artificial media.
CONTROL:
Control
is based on early detection and chemotherapy. In the face of multiple
confirmed
cases of resistance to dapsone, combination of this medication with
rifampicin
is presently recommended for paucibacillary leprosy, and the same two
medications
in combination with clofazimine for multibacillary leprosy. Rifampicin
has a rapid bactericidal effect and eliminates contagion in patients in
1 to 2 weeks. The isolation of patients in leprosariums is no longer
necessary,
since the chemotherapy effectively eliminates infectiousness and
thereby
interrupts transmission of the disease.
VIBRIOSIS
U.S.
Centers for Disease Control and Prevention: Division of Bacterial and
Mycotic
Diseases
Vibrio
parahaemolyticus: General
Information | Technical
Information | Additional
Information
Vibrio
vulnificus: General
Information | Technical
Information | Additional
Information
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
Vibrios
other than Vibrio cholerae that cause human disease are Vibrio
parahaemolyticus,
Vibrio vulnificus and Vibrio alginolyticus. All are halophilic marine
organisms.
Infection is acquired by exposure to organisms in contaminated,
undercooked,
or raw crustaceans or shellfish and warm ( 20o C) ocean waters and
estuaries.
Infections are more common during the summer months from regions along
the Atlantic coast and the Gulf of Mexico in the United States and from
tropical waters around the world. Oysters are implicated in up to 90%
of
food-related cases. V. parahaemolyticus causes an acute watery diarrhea
with crampy abdominal pain and fever, typically occurring within 24
hours
after ingestion of contaminated shellfish. The disease is self-limited,
and antimicrobial therapy is usually not necessary. V. parahaemolyticus
may also cause cellulitis and sepsis, though these findings are more
characteristic
of V. vulnificus infection. V. vulnificus and V. alginolyticus-neither
of which is associated with diarrheal illness-are important causes of
cellulitis
and primary bacteremia, which may follow ingestion of contaminated
shellfish
or exposure to sea water. Cellulitis with or without sepsis may be
accompanied
by bulla formation and necrosis with extensive soft tissue destruction,
at times requiring debridement and amputation. The infection can be
rapidly
progressive and is particularly severe in immunocompromised
individuals-especially
those with cirrhosis-with death rates as high as 50%. Patients with
chronic
liver disease and those who are immunocompromised should be cautioned
to
avoid eating raw oysters. Tetracycline at a dose of 500 mg four times a
day is the drug of choice for treatment of suspected or documented
primary
bacteremia or cellulitis caused by Vibrio species. V. vulnificus is
susceptible
in vitro to penicillin, ampicillin, cephalosporins, chloramphenicol,
aminoglycosides,
and fluoroquinolones, and these agents may also be effective. V.
parahaemolyticus
and V. alginolyticus produce betalactamase and therefore are resistant
to penicillin and ampicillin, but susceptibilities otherwise are
similar
to those listed for V. vulnificus.
LISTERIOSIS
U.S.
Centers for Disease Control and Prevention: Division of Bacterial and
Mycotic
Diseases
Listeriosis:
General
Information | Technical
Information | Additional
Information
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Circling
disease)
AGENT
Listeria
monocytogenes, gram positive, pleomorphic rod
RESERVOIR
AND INCIDENCE
Isolated
from fish, birds, swine, horses, ruminants, guinea pigs, ferrets,
gerbils,
rabbits, and chinchillas. The principle reservoir of the organism is in
forage, water, mud, and silage. The seasonal use of silage as fodder is
frequently followed by an increased incidence of listeriosis in
animals.
TRANSMISSION:
Outbreaks
have been reported associated with ingestion of unpasteurized milk and
cheese and contaminated vegetables; some sporadic cases may also be due
to foodborne transmission. Refrigeration of foods may provide selective
growth of Listeria. Papular lesions on hands and arms may occur from
direct
contact with infectious material or soil contaminated with infected
animal
feces. In neonatal infections, the organism may have been transmitted
from
mother to fetus in utero or during passage through the infected birth
canal.
Person-to-person transmission through venereal contact is possible, as
is infection from inhalation of the organism.
DISEASE
IN ANIMALS:
Two forms
exist, the meningoencephalitic and visceral. The former involves
neurological
signs with dullness and somnolence. Drooling and lack of interest in
food
and mastication soon follow. There is lateral deviation of the head
with
a tendency to circle. Paralysis then sets in with recumbency and death
from respiratory failure. The visceral from involves abortion, with
retained
placenta. Microabscesses occur throughout the brain. Visceral lesions
involve
multiple foci of necrosis in the liver, spleen and heart. Placental
lesions
are characteristic with yellow necrotic foci and multiple granulomas in
the fetal liver. Abscess formation in the eye can lead to blindness.
Fatality
is very high, approaching 3-30% in outbreaks.
DISEASE
IN MAN:
Symptomless
fecal carriage is common. Fever, headache, nausea, vomiting,
endocarditis,
granulomatous lesions in multiple organs, cutaneous involvement,
coryza,
conjunctivitis, metritis with abortion, sepsis, & meningitis.
Granulomatous
lesions and abscesses occur in the liver and other organs and beneath
the
skin. Focal necrosis in the placenta with mononuclear infiltration is
seen.
Fatality rates may exceed 20%.
DIAGNOSIS:
culture
and isolation (special media required). Serologic tests are unreliable
because of cross reactions with other bacterial species.
TREATMENT:
Ampicillin
plus an aminoglycoside or Trimethoprim-sulfamethoxazole.
PREVENTION\CONTROL:
Caution
and protective clothing when handling infected tissues. Pregnant women
and immunocompromised individuals should avoid contact with potentially
infective materials such as aborted animal fetuses and known infected
persons;
they should eat only properly cooked meats and pasteurized dairy
products.
LEPTOSPIROSIS
U.S.
Centers for Disease Control and Prevention: Division of Bacterial and
Mycotic
Diseases
Leptospirosis:
General
Information | Technical
Information | Additional
Information
Office
International des Epizooties
Leptospirosis:
Manual of standards Diagnostic Tests and Vaccines 2000
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
[Weil's
disease, Hemorrhagic jaundice (Leptospira icterohaemorrhagiae),
canicola
fever (L. canicola), dairy worker fever (L. hardjo)]
AGENT
Spirochete,
Leptospira. Pathogenic leptospires belong to the species Leptospira
interrogans,
which is subdivided into more than 200 serovars. The main natural
reservoirs
for human infection vary with serovar: L. canicola in dogs, L. hardjo
in
cattle, L. pomona in swine, and L. icterohaemorrhagiae in rats.
RESERVOIR
AND INCIDENCE
Rats,
mice, field moles, guinea pigs, gerbils, squirrels, rabbits, hamsters,
reptiles, nonhuman primates, livestock, and dogs. In one study, 40 % of
stray dogs were seropositive. Rats and mice are common animal hosts for
L. ballum. Infection in mice is inapparent and can persist for the
animal's
lifetime. *Rodents are the only major animal species that can shed
leptospires
throughout their life-span without clinical manifestations. Active
shedding
by lab animals can go unrecognized until personnel handling the animals
become clinically ill.
TRANSMISSION:
Handling
affected animals, contaminating hands, or abrasions with urine, or
aerosol
exposure during cage cleaning are most common. The organism is often
transmitted
to humans by the urine of the reservoir host. The organism may also
enter
through minor skin lesions and probably via the conjunctiva. Many
infections
have followed bathing or swimming in infected waters.
DISEASE
IN ANIMALS:
In cattle,
fever and anorexia occur with rapid decline in milk yield and atypical
mastitis. Pregnant cows abort with retention of the placenta. Also,
mild
jaundice and severe anemia occurs with enlarged and friable liver and
swollen
kidneys. In pigs subclinical infection is common, though it can cause
abortion
and birth of weak piglets. In dogs and cats, gastroenteritis, jaundice,
and nephritis may occur.
DISEASE
IN MAN:
Ranges
from inapparent infection to severe infection and death. Biphasic
Illness
a. Weakness, headache, myalgia, malaise, chills, & fever. b.
Leukocytosis,
painful orchitis (testes not usually enlarged), conjunctival effusion,
and rash. Icteric leptospirosis (Weil's syndrome-usually caused by L.
icterohaemorrhagiae)
is the most severe form of the disease, characterized by impaired renal
and hepatic function, abnormal mental status, hypotension, and a 5-10%
mortality rate. Signs and symptoms are continuous and not
biphasic.
DIAGNOSIS:
Early
in the disease, the organism may be identified by darkfield examination
of the patient's blood or by culture on a semisolid medium. Culture is
difficult and requires several weeks. A rapid diagnosis is made with
the
DOT-ELISA test. *Leptospires can be recovered only from mature mice
even
though antibodies can be detected from infected mice of all ages.
TREATMENT:
Penicillins
or tetracyclines. Can eliminate L. ballum from a colony (mice) with
1000
gm chlortetracycline HCL/Ton of feed for ten days.
PREVENTION\CONTROL:
Vaccination
in cattle, swine, and dogs Avoid swimming in or drinking from
potentially
contaminated water. Protect workers by providing boots and gloves.
Rodent
control. Drain wet ground. Doxycycline chemoprophylaxis for persons at
high exposure.
BORRELIOSIS
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Relapsing
fever, tick-borne relapsing fever, spirochetal fever, vagabond fever,
famine
fever) A widely distributed bacterial infection spread from wild
rodents
by ticks or lice, with high fatality Tick-borne relapsing fever occurs
in Africa, the Americas, Asia and possibly parts of Europe. The
causative
agents are Borrelia recurrentis and several other borrelia strains
(bacterium).
There is no vaccine.
RESERVOIR
AND MODE OF
TRANSMISSION:
Epidemic
louse-borne infection is not considered zoonotic. Endemic tick-borne
relapsing
fever is transmitted from the natural wild rodent reservoir by tick
bites
to humans and dogs. Transovarial transmission in ticks occurs.
Blood-borne
person-to-person and intrauterine transmission have been reported.
INCUBATION
PERIOD:
Humans:
1-15 days. Animals.Unknown.
CLINICAL
FEATURES:
Humans.
Sudden onset of fever lasting for 3-5 days ends with a crisis. Then a
febrile
period of 2-4 days is followed by one to ten or more recurrences of
fever
accompanied by severe headaches, nausea, vomiting, diarrhoea, jaundice
and sometimes a macular rash with bleeding due to thrombocytopenia.
Meningitis
and cranial nerve involvement are possible. Animals. Arthritis and
fever
predominate in infected dogs. The arthritis recurs and may progress to
chronic deformity.
PATHOLOGY:
Humans.
Many lesions occur, including enlarged, soft, infarcted spleen,
hepatomegaly,
hemorrhages in bone marrow and skin, myocarditis, bronchopneumonia, and
meningitis. Animals. Arthritis, especially of the phalangeal joints,
occurs
with the possibility of progression to fibrosis of the joint capsule
and
ankylosis.
DIAGNOSIS:
Humans.
Identify borrelia in thick blood smears. Otherwise isolate the pathogen
by inoculation of blood into susceptible animals if possible. Animals.
Inoculate blood or tissues into rats or mice.
PROGNOSIS:
Humans.
The fatality rate is up to 40 per cent. Animals. Although fatality is
uncommon,
the lesions tend to be progressive.
PREVENTION:
Humans
and animals. Control tick vectors and prevent tick bites.
TREATMENT:
Humans.
A single dose of tetracycline or erythromycin, 0.5 g orally, or a
single
dose of procaine penicillin G, 600,000 units intramuscularly, probably
constitutes adequate treatment for louse-borne relapsing fevers.
Because
of higher relapse rates, tick-borne disease is treated with 0.5 g of
tetracycline
or erythromycin given 4 times daily for 5-10 days. Jarisch-Herxheimer
reactions
may occur and respond to aspirin given every 4 hours. Pretreatment with
steroids is not effective in preventing this reaction. Animals.
Tetracycline,
penicillin, erythromycin, and ceftriaxone at standard dosages for 21-28
days.
LEGISLATION:
Humans.Louse-borne
relapsing fever is notifiable to the World Health organization.
Tick-borne
infection may be notifiable in some countries (e.g. the UK).
Animals.None.
LYME
DISEASE
U.S.
Centers for Disease Control and Prevention: Division of Vector-Borne
Infectious
Diseases
Lyme
Disease:
Home
Page
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Lyme
arthritis, Bannworth's syndrome, tick-borne meningopolyneuritis,
erythema
chronicum migrans [ECM], Steere's disease)
AGENT:
Spirochete,
Borrelia burgdorferi
RESERVOIR
AND INCIDENCE
First
implicated in 1982 as agent in a 1975 epidemic of juvenile inflammatory
arthropathy in Old Lyme Connecticut. Cases have been reported from 46
states
and the annual number of Lyme disease cases has increased 18 fold from
497 to 8803. It is now the most common tick transmitted disease in the
USA. Also seen in Europe, England, Soviet Union, China, Japan,
Southeast
Asia, South Africa, Australia, and Canada.
TRANSMISSION:
Transmitted
mostly by Ixodes dammini and other ixodid ticks (three host tick with a
two to three year life cycle). Ixodes dammini has a broad range of
hosts;
adults prefer white tailed deer but will also parasitize dogs, horses,
and humans. Larvae feed primarily on rodents, especially mice. Nymphs
feed
on all hosts and appears to be primarily responsible for transmission
of
the disease to people. Birds are an important reservoir and means of
dispersal.
Also found in Dermacentor, Rhipicephalus and Amblyomma and other ticks
and biting insects, including mosquitoes, fleas, and biting flies.
Because
of lack of any proof to the contrary it is generally believed at this
time
that any potential increased risk to human beings from infected animals
is attributable to animals bringing ticks into areas of human
habitation
rather than any pet transmission. Dogs appear to be at greater risk
than
humans.
DISEASE
IN ANIMALS:
Serologic
evidence has been reported in the dog, cat, horse, and ruminants.
However,
correlation with disease is lacking except in the dog. The dog exhibits
the same symptoms as noted below for humans. Expanding skin lesions
have
been noted in mice and rabbits.
DISEASE
IN MAN:
Multisystemic
disease which may have chronic sequelae; an annular rash known as
erythema
chronicum migrans (ECM) develops in 60-80% of patients in the area of
the
tick bite and is considered pathognomonic. Also flu like symptoms,
which
resolve in about three weeks. 8-10% of people develop cardiac
involvement
several weeks later. Manifestations include atrioventricular block,
cardiomyopathy,
heart failure, myocarditis, and pancarditis. 15% develop neurologic
disorders
such as facial nerve palsies which usually resolve. Other
manifestations
include meningitis, cranial neuritis, radiculoneuritis, neuropathy, and
encephalopathy. 60% develop the most common sequelae, arthritis.
Disease
may remain latent with symptoms developing 4 years after
seroconversion.
DIAGNOSIS:
Most common
test is detecting antibody titers by IFA or ELISA (on blood, CSF or
synovial
fluid). Culture is definitive but is difficult and requires special
media
such as Barbour-Stoener-Kelly media. Histologically with Dieterle
Silver
Stain or immunoperoxidase stains, but is often unrewarding.
TREATMENT:
A positive
serology is no grounds for treatment when no clinical signs are
present.
Borrelia burgdorferi is sensitive to tetracycline and moderately
sensitive
to penicillin. amoxicillin, ceftriaxone, and imipenem are also highly
active.
PREVENTION\CONTROL:
Tick control
care when removing ticks or when handling potentially infective
materials
a vaccine against Lyme Disease tested in hamsters has been found
effective.
More research is needed but in the future vaccination may be beneficial
for those at constant risk of exposure.
ZOONOTIC
DISEASES
ENTERIC
INFECTIONS
CAMPYLOBACTERIOSIS
Centers
for Disease Control and Prevention: National Center for Infectious
Diseases
Campylobacteriosis
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Vibriosis,
vibrionic abortion)
AGENT:
Campylobacter
(Vibrio) fetus ss. jejuni, a gram negative, microaerophilic, curved,
motile
rod that is worldwide in distribution.
RESERVOIR
AND INCIDENCE
Isolated
from laboratory animals including dog, cat, hamsters, ferrets (>60 %
in
one study), nonhuman primates, rabbits, swine, sheep, cattle, and birds
Although most cases of human campylobacteriosis are of unknown origin,
infection after contact with sick animals has been well documented. *In
most reports of pet to human transmission of C. jejuni, diarrheic
puppies
or kittens from pounds have been the source of infection. Pet birds,
chickens,
and kittens are implicated in other reports. A lab animal technician
developed
Campylobacter enteritis after feeding and cleaning up after a recently
imported nonhuman primate. The organism was first isolated from
nonhuman
primates from Macaca fascicularis in 1979 and has since been reported
in
baboons, rhesus, patas, and marmosets. Can be shed for long periods of
time in stool by asymptomatic carriers. Younger animals seem more
likely
to acquire the infection and hence may more commonly shed the
organism.
TRANSMISSION:
Transmission
is thought to occur by the fecal-oral route, through contamination of
food
or water, or by direct contact with infected fecal material. The
organism
has also been isolated from houseflies. At 40 C the organism is viable
for three weeks in feces and milk, four weeks in water, and five weeks
in urine. Campylobacter is shed in the feces for at least six weeks
after
infection. Infected children may transmit infection to puppies or
kittens,
which may then expose other children. Poultry and cattle are the main
reservoirs
for human infection, which is acquired by ingesting contaminated raw
milk,
undercooked chicken or other food contaminated in the kitchen.
DISEASE
IN NONHUMAN
PRIMATES:
Variable.
the majority are asymptomatic carriers. Mild to severe enteritis may be
seen accompanied by fever, vomiting, and mucus and blood in the feces.
Bacteremia may occur complicated by meningitis or abortion. Most signs
appear 1 to 7 days after exposure and affect primarily the jejunum,
ileum,
and colon.
DISEASE
IN FERRETS:
Asymptomatic
to proliferative colitis. Shed organisms for long period of time (>
16
weeks).
DISEASE
IN OTHER ANIMALS:
Has also
been shown to cause hepatitis in poultry, proliferative ileitis in
hamsters,
and abortion in ruminants. In all animals, it may be associated with
diarrhea,
especially when acting secondarily to virus infection.
DISEASE
IN MAN:
Acute
gastrointestinal illness, diarrhea with or without blood, abdominal
pain,
and fever. It may cause pseudoappendicitis and, rarely, septicemia and
arthritis. Usually a brief, self-limiting disease. In humans the
asymptomatic
carrier state is rare. Reinfection is possible in both animals and
man.
DIAGNOSIS:
1. Rapid
diagnosis is done with dark field or phase contrast microscopy of fecal
material. 2. This is confirmed by stool culture which requires a
special
selective growth media(CAMPY-BAP) and incubation at 43oC with 10% CO2,
5% O2 and 85% Nitrogen. 3. Warthin Starry stain and histo 4. Various
techniques
are being used to detect seroconversion to the antigens of
Campylobacter.
TREATMENT:
Animals
can be treated based on culture and sensitivity. Currently erythromycin
is the drug of choice, but does not eliminate the carrier state.
Tetracycline
or ciprofloxacin are alternatives.
PREVENTION\CONTROL:
Vaccines
provide partial protection of short duration and routine use is not
recommended.
Control is aimed at isolation of affected individuals and personal
hygiene.
An increased awareness of the potential of infection due to
Campylobacter
is of primary importance. Thoroughly cook all foodstuffs derived from
animal
sources, particularly poultry. Recognize, prevent, and control
Campylobacter
infections among domestic animals and pets. Wash hands after handling
poultry
and animal feces.
COLIBACILLOSIS
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Colibacteriosis,
colitoxemia, white scours, gut edema of swine)
AGENT:
Escherichia
coli are gram-negative, aerobic, and facultatively anaerobic
medium-sized
rods.
RESERVOIR
AND INCIDENCE
Worldwide;
some endemic areas exist in developing countries.
TRANSMISSION:
Some serotypes
are species-specific, others are not. Milk, milk products, and meat
products
can contain pathogenic serotypes. Foods of animal origin and contact
with
dogs and cats have been indicated as sources of infection for
children.
DISEASE
IN ANIMALS:
Calf diarrhea
(white scours) is an acute disease causing mortality in calves less
than
10 days old. It manifests itself as serious diarrhea, with whitish
feces
and rapid dehydration. Mastitis caused by E. coli appears especially in
older cows with dilated milk ducts. A long-term study of horse fetuses
and newborn colts found that close to 1% of abortions and 5% of deaths
of newborns were due to E. coli. Neonatal enteritis caused by E. coli
in
suckling pigs begins 12 hours after birth with a profuse watery
diarrhea,
and may end with fatal dehydration. Edema in suckling pigs (gut edema)
is an acute disease that generally attacks between 6 and 14 weeks of
age.
It is characterized by sudden onset, incoordination, and edema of the
eyelids,
the cardiac region of the stomach, and sometimes other parts of the
body.
During septicemic diseases of fowl, such as cases of salpingitis and
pericarditis,
pathogenic serotypes of E. coli have been isolated. A colibacillary
etiology
has also been attributed to Hjarre's disease (coligranuloma), which is
a condition in adult fowl characterized by granulomatous lesions in the
liver, cecum, spleen, bone marrow, and lungs.
DISEASE
IN HUMANS:
The enterotoxigenic
stains (ETEC) cause profuse and watery diarrhea, abdominal colic,
vomiting,
acidosis, and dehydration. Enteroinvasive strains cause a dysenteric
syndrome
with mucoid diarrhea, at times tinged with blood. E. coli is also an
important
agent of urogenital infections.
DIAGNOSIS:
Stool
culture or immunoassays for enterotoxins.
TREATMENT:
Ciprofloxacin
or trimethoprim-sulfa.
PREVENTION/CONTROL:
With respect
to man, control measures include: a) personal cleanliness and hygienic
practices, sanitary waste removal and b) protection of food products.
Vaccines
for swine and bovine have been developed.
SALMONELLOSIS
Centers
for Disease Control and Prevention: National Center for Infectious
Diseases
Salmonellosis
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Enteric
paratyphosis)
AGENT:
Gram negative
bacteria. Out of 1600 recognized serotypes of Salmonella, S.
typhimurium
& S. enteritidis have been associated most commonly with lab animal
colony infections. In the U.S., 5 million cases are diagnosed annually.
S. typhi, the cause of Typhoid Fever, rarely occurs in the U.S. and is
not discussed here.
RESERVOIR
AND INCIDENCE
The organism
inhabits the intestinal tract of many animals including birds, cattle,
sheep, pigs, lab. animals (rats, mice, hamsters, guinea pigs, nonhuman
primates) and humans. Salmonella occurs worldwide. *The house mouse may
also be a reservoir of the infection and may play a role in human and
animal
salmonellosis. Humans, rarely, and animals may be carriers and
asymptomatic
shedders of the organism. *Salmonella prevalence in the U.S. canine
population
may be 10% or more. *Prevalence data from 8 studies conducted worldwide
indicated that a wide range (0.6-27%) of cats were culture-positive for
Salmonella. *Salmonella carriers in newly imported Rhesus and
Cynomolgus
monkeys exceeded 20% in some shipments. *Birds, reptiles, and turtles
are
especially dangerous sources of Salmonellosis. 94% of all reptiles
harbor
Salmonella. Turtles alone in 1970 may have caused 280,000 human cases
of
Salmonellosis. *In 1975 the FDA ruled it illegal to sell a. Viable
Turtle
eggs b. Live turtles with a carapace length < 10.2cm (4 inches) c.
Exceptions
- Educational & scientific institutions and marine turtles. d.
Marine
turtles have not been shown to be a reservoir of Salmonella THERE WAS A
77% DECREASE IN TURTLE ASSOCIATED SALMONELLOSIS AFTER ENACTMENT OF THIS
LAW.
TRANSMISSION:
Indirect
transmission via contaminated food and water are the most common
sources
but transmission may also be by direct contact. It is a common
contaminant
of sewage. Found in many environmental water sources. Environmental
contamination
continues to be a potential source of infection for lab animals and
secondarily
for personnel handling those animals. *Animal feed containing animal by
products continues to be a source of Salmonella contamination,
especially
if the diets consist of raw meal and have not undergone the pelleting
process.
DISEASE
IN ANIMALS:
Can be
asymptomatic with clinical signs precipitated by stress; penetration of
the infection into the mucosa is followed by inflammation, especially
ileitis,
progressing to inflamed mesenteric lymph nodes in the mesentery,
possibly
progressing to septicemia and pneumonia especially in calves. Calves
undergo
epizootic outbreaks of diarrhea with high mortality. Abortion in cattle
is caused by massive proliferation of salmonella in the placenta
leading
to placental necrosis. High percentage of survivors become carriers.
Infected
sheep, goats, and poultry usually show no signs of infection.
DISEASE
IN MAN:
Acute
gastroenteritis with sudden onset of abdominal pain, diarrhea, nausea,
and fever. May lead to septicemia. May be an inapparent infection.
DIAGNOSIS:
Fecal
Culture with selective media. Can get false negatives, though because
organism
is shed intermittently. In the carrier state bacterium resides in the
gall
bladder (NHP).
TREATMENT:
Symptomatic.
Severely ill patients are treated with trimethoprim-sulfamethoxazole,
ampicillin,
or ciprofloxacin.
PREVENTION\CONTROL:
Rapid
detection and treatment (acute and chronic) in lab animals. Treatment
based
on culture and sensitivity. Cull carrier animals. Watch during
quarantine
period. Sanitation and hygiene, protective clothing, gloves Rodent,
bird
& wild animal control is important. Examine feed and bedding and
pasteurize
or autoclave, if necessary. Consider screening animal care personnel
for
inapparent Salmonella infection to prevent the introduction of
Salmonella
into the colony from infected workers. Thoroughly cook all foodstuffs
derived
from animal sources. Exclude animal care personnel with diarrhea.
STAPHYLOCOCCAL
FOOD POISONING
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Staphylococcal
Alimentary Toxicosis, Staphylococcal Gastroenteritis)
AGENT:
Coagulase-positive
strains of Staphylococcus aureus, a gram-positive cocci.
RESERVOIR
AND INCIDENCE
Worldwide.
The principle reservoir is the human carrier. Infected cows, fowls, and
dogs may give rise to and be a source of staphylococcal poisoning in
man.
TRANSMISSION:
A high
proportion of healthy humans (30-35%) have staphylococci in the
nasopharynx
and on the skin. Sneezing, coughing, expectorating can contaminate
food.
Similarly, he may contaminate foods handled if he has a skin lesion.
Milk
from cow udders infected can contaminate numerous milk products.
Contaminated
egg contents can also be a source of infection.
DISEASE
IN ANIMALS:
Mastitis
in cattle. Pyoderma, impetigo, folliculitis, and furunculosis in dogs.
In fowl, staphylococcal infection can cause diseases ranging from
pyoderma
to septicemia with different locations (salpingitis, arthritis, and
other
disorders).
DISEASE
IN HUMANS:
The major
symptoms are nausea, vomiting, abdominal pains, and diarrhea. It is the
cause of toxic shock syndrome in women.
DIAGNOSIS:
Culture
of vomitus, feces, or a suspected food item.
TREATMENT:
Electrolyte
and fluid replacement. Ciprofloxacin.
PREVENTION/CONTROL:
Reduce
food handling time. Exclude persons with boils, abscesses, and other
purulent
lesions from handling food. Educate food handlers in strict food
hygiene.
ANTHRAX
Centers
for Disease Control and Prevention: National Center for Infectious
Diseases
Anthrax
(Bacillus anthracis infection)
Office
International des Epizooties
Anthrax:
Manual of standards Diagnostic Tests and Vaccines 2000
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Malignant
pustule, wool-sorters' disease, charbon, malignant edema, splenic
fever)
An acute bacterial infection of humans and animals which may be rapidly
fatal. The disease occurs worldwide and is enzootic in certain African
and Asian countries. It is an occupational hazard of persons such as
wool-sorters,
fellmongers, knackermen, farm workers and veterinarians in contact with
infected animals or their products (e.g., blood, wool, hides and
bones).
The causative agent is Bacillus anthracis (bacterium).
RESERVOIR
AND MODE OF
TRANSMISSION:
All domestic,
zoo and wild animals are potentially at risk of infection. Anthrax
bacilli
are released from infected carcasses and form resistant spores on
exposure
to air. These spores contaminate soil for many years. Humans are
usually
infected by inoculation from direct contact with infected animals,
carcasses
or animal products and contaminated soil. Inhalation or ingestion of
spores
may occur. Animals are infected from contaminated feed, forage, water
or
carcasses. Laboratory accidents have occurred.
INCUBATION
PERIOD:
Humans.
Cutaneous 3-10 days inhalation 1-5 days gastrointestinal 2-5 days.
Animals.
1-5 days.
CLINICAL
FEATURES:
Humans.
Various forms include: 1. Cutaneous anthrax; localized ulceration and
scab
with fever and headache which may be followed within a few days by
septicemia
and meningitis. 2. Inhalation anthrax; fulminating pneumonia. 3.
Intestinal
anthrax; acute gastroenteritis with bloody diarrhoea. Animals. Peracute
cases are found dead or moribund. Acute cases show fever, excitation
followed
by depression, incoordination, convulsion and death. Chronic cases show
edema of throat, pharynx and brisket, especially in pigs.
PATHOLOGY:
Humans.
Features include black scab (eschar) with edema, enlargement of
regional
lymph nodes and possibly septicemia; pneumonia and generalized
hemorrhages.
Animals. Carcasses should not be opened, hence necropsy is rarely
carried
out. Main features include failure of the blood to clot and hemorrhages
throughout the body. The spleen is enlarged and softened. The
subcutaneous
swelling, mainly about the neck and throat of affected pigs and horses,
contains gelatinous fluid. The blood contains very large numbers of B.
anthracis.
DIAGNOSIS:
Humans.
Identify B. anthracis in stained blood smears or by inoculation of
laboratory
animals. Culture swabs from wounds. Animals. As for humans. Specific
antigen
for anthrax may be found in animal products (e.g. hides) using a
precipitin
(Ascoli) test.
PROGNOSIS:
Humans.
Untreated cutaneous anthrax has a fatality rate of 5-20 Per cent and
gastrointestinal
anthrax of 25-75 per cent. Pulmonary anthrax is usually fatal. Animals.
The condition is usually fatal in cattle unless treated early. Pigs and
horses are more resistant.
PREVENTION:
Humans.
Prohibit contact with infected animals and their products. Establish
environmental
and personal hygiene (e.g., ventilation and protective clothing) where
a special risk exists. Treat wounds promptly and disinfect imports of
hairs
and wool. Vaccination may protect those occupationally exposed to risk.
Apply strict laboratory safety measures. Isolate infected patients,
with
concurrent disinfection. Animals. Sterilize, or avoid using, meat and
bone
meal from high-risk countries for animal feed. Vaccinate livestock
grazing
in enzootic area. Dispose of infected carcasses safely and fence off
areas
contaminated by inadequately buried carcasses.
TREATMENT:
Humans.
The mortality rate is high despite proper therapy, especially in
pulmonary
disease. Penicillin G, 2 million units IV every 4 hours, is the therapy
of choice. tetracycline, 500 mg orally every 6 hours, may be used for
mild,
localized cutaneous infection. Animals. Penicillin injection of all
animals
showing fever after the first case is confirmed. This involves checking
temperatures twice daily.
VACCINATION:
Humans.
Offered to workers at risk. Animals. Non-encapsulated Stern strain
vaccine
can be used in all species of domestic animal. Annual vaccination of
grazing
animals using spore or alum precipitated antigen vaccine in areas of
high
risk is recommended.
LEGISLATION:
Humans.
The disease is notifiable in most countries. It is a recognized
occupational
disease in some countries, including the UK. Animals. Notifiable in
many
countries with mandatory disposal of infected carcasses by burning or
deep
burial under lime. Opening of moving suspect carcasses is
prohibited.
STAPHYLOCOCCAL FOOD POISONING
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
SYNONYMS:
Staphylococcal
alimentary toxicosis, staphylococcal gastroenteritis.
ETIOLOGY:
Coagulase-positive
strains of Staphylococcus aureus that produce enterotoxins. Very few
coagulase-negative
stains are enterotoxigenic. The toxin is preformed in the food
involved.
To date, six types of enterotoxins are known: A, B, C, D, E, and F; of
these A is the most prevalent in outbreaks. Enterotoxin F is implicated
in toxic shock syndrome (TSS). Some strains can produce two or even
three
different enterotoxins. The toxins are heat-resistant and can withstand
a temperature of 100oC for 30 minutes.
GEOGRAPHIC
DISTRIBUTION:
Worldwide.
THE
DISEASE IN MAN:
The incubation
period is short, generally 3 hours after ingestion of the food
involved.
The interval between consumption of the enterotoxin and the first
symptoms
can vary from 30 minutes to 8 hours, depending on the quantity of toxin
ingested and the susceptibility of the individual. The major symptoms
are
nausea, vomiting, abdominal pains, and diarrhea. Some patients may show
low pyrexia (up to 38oC). More serious cases manifest prostration,
cephalalgia,
abnormal temperature, and lowered blood pressure, as well as blood and
mucus in the stool and vomit. The course of the disease is usually
benign
and the patient recovers without medication in 24 to 72 hours.
Recently,
a toxic shock syndrome has been described. Symptoms consist of
vomiting,
diarrhea, high fever, erythroderma, edema, renal insufficiency, and
toxic
shock. Most patients are women who become ill during their menstrual
period.
The above-described symptoms also are observed in association with
abscesses
and osteomyelitis caused by S. aureus. A staphylococcal enterotoxin
designated
F was isolated from 94% of these patients strains of S. aureus from
nine
patients with toxic shock were examined, and production of enterotoxin
F was confirmed in eight of them; only 42% of 50 strains isolated from
other hospitalized patients produced this toxin. Toxin F production was
not found in 48 strains originating from animal clinical specimens. Of
24 strains from healthy human carriers, 25% produced the toxin.
SOURCE
OF INFECTION
AND MODE OF TRANSMISSION:
The principal
reservoir of is S. aureus is the human carrier. A high proportion (from
30 to 35%) of healthy humans have staphylococci in the nasopharynx and
on the skin. A carrier with a respiratory disease can contaminate foods
by sneezing coughing, or expectorating. Similarly, he may contaminate
foods
he handles if he has a staphylococcal skin lesion. However. even if not
sick himself, the carrier may spread the agent by handling food
ingredients.
utensils, and equipment. or the finished food product. According to
different
authors, the proportion of enterotoxin-producing S. aureus strains of
human
origin varies between 18 and 75%. The proportion of toxigenic strains
isolated
from various sources (human, animal, and food) is very high. Strains of
human origin predominate in epidemics, but animals are also reservoirs
of the infection. Milk from cow udders infected with staphylococci can
contaminate numerous milk products. Many outbreaks have been produced
by
consumption of inadequately refrigerated raw milk or cheeses from cows
whose udders harbored staphylococci. The largest outbreak affected at
least
500 students in California between 1977 and 1981 and was traced to
chocolate
milk. In developing countries, where refrigeration after milking is
often
inadequate, milk and milk products may be an important source of
staphylococcal
intoxication. According to recent investigations, a high proportion of
strains isolated from staphylococcal mastitis produce enterotoxin A,
which
causes many outbreaks in humans. In several investigations it was
possible
to isolate from skin lesions and cow's milk the S. aureus phage type
80/81,
which is related to epidemic infections in man. One of the studies
proved
that phage type 80/81 produced interstitial mastitis in cows. The same
phage type was found among animal caretakers, which indicates that the
bacterium is intertransmissible between man and animals and that the
latter
may reinfect man. Infected fowl and dogs may also give rise to and be a
source of staphylococcal poisoning in man. One subject that deserves
special
attention is the appearance of antibiotic-resistant strains in animals
whose food includes antibiotics. Concern exists over the possible
transmission
of these strains to man. On several occasions, resistant stains have
been
found both in animals (cows, swine, and fowl) and in their caretakers,
with the same antibiotic resistance. Moreover, "human" strains (phage
typed)
have on occasion been isolated from the nostrils and lesions of other
species
of domestic animals. A variety of foods and dishes may be vehicles of
the
toxin. If environmental conditions are favorable, S. aureus multiplies
in the food and produces enterotoxins. Once made, the toxin is not
destroyed
even if the food is subjected to boiling while being cooked.
Consequently,
the toxin may be found in the food whereas staphylococci are not. An
important
causal factor in food-borne intoxications is holding food at room
temperature,
which permits multiplication of staphylococci. Lack of hygiene in food
handling is another notable factor. Frequently, outbreaks of food
poisoning
may be traced to a single dish.
THE
ROLE OF ANIMALS
IN THE EPIDEMIOLOGY OF THE DISEASE:
Most outbreaks
are caused by human strains, and to a lesser degree by strains from
cattle
and other domestic animals. Animal products -- such as meat, ham, milk,
cheese, cream, and ice cream -usually constitute a good substrate for
staphylococcal
multiplication. Milk pasteurization offers no guarantee of safety if
toxins
were produced before heat treatment, as the toxins are heat-resistant.
Outbreaks have been caused by reconstituted powdered milk, even when
the
dried product contained few or no staphylococci.
DIAGNOSIS:
The short
incubation period between ingestion of contaminated food and appearance
of symptoms is the most important clinical criterion. Laboratory
confirmation,
when possible, is based above all on demonstration of the presence of
enterotoxin
in the food. Biological methods (inoculation of cats with cultures of
the
suspect food, or of rhesus monkeys with the foodstuffs or cultures) are
expensive and not always reliable. As substitutes, serologic methods
such
as immunodiffusion, immunofluorescence, hemagglutination inhibition,
and,
recently, ELISA are increasingly used. In febrile patients, blood
cultures
are indicated. Isolation of enterotoxigenic staphylococcal strains from
foods and typing by phage or, more recently, by immunofluorescence have
epidemiologic value. Quantitative examination of staphylococci in
processed
or cooked foods serves as an indicator of hygienic conditions in the
processing
plant and of personnel supervision.
TREATMENT:
In humans,
treatment usually consists of replacement of fluids and electrolytes
and,
very rarely, management of hypovolemic shock and respiratory
embarrassment.
If botulism is suspected, polyvalent antitoxin must be administered.
Historically,
antimicrobial drugs have not been recommended unless a specific
microbial
agent producing progressive systemic involvement can be identified.
Preliminary
data now suggest that ciprofloxacin, 500 mg every 12 hours for 5 days,
may shorten the duration of diarrhea and lead to a more rapid
resolution
of symptoms. Antimotility drugs may relieve cramping and decrease
diarrhea
in mild cases. Their use should be limited to patients without fever
and
without dysentery (bloody stools), and they should be used in low
doses.
CONTROL:
It includes
the following measures: a) education of persons who prepare food at
home
or commercially in proper personal hygiene; b) exclusion from handling
food of individuals with abscesses or other skin lesions; and c)
refrigeration
of all foods to prevent bacterial multiplication and formation of
toxins.
Foods should be kept at room temperature as little time as possible.
The
veterinary milk inspection service should supervise dairy
installations,
ensuring that refrigeration units function correctly and are used
immediately
after milking, and that milk is refrigerated during transport to
pasteurization
plants. The veterinary meat inspection service should be responsible
for
enforcing hygienic regulations before and after slaughter as well as
during
handling and production of meat products. Control of hygienic
conditions
in meat retail establishments ts also important.
LEPROSY
Centers
for Disease Control and Prevention: Division of Bacterial and Mycotic
Diseases
Hansen's
Disease (Leprosy)
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Hansen's
disease)
AGENT:
Mycobacterium
leprae, a polymorphic acid-fast bacillus.
RESERVOIR
& INCIDENCE:
The world
prevalence is estimated to be between 10 and 12 million. Newly
recognized
cases in the USA are diagnosed principally in California, Hawaii,
Texas,
Florida, Louisiana, and New York City, and in Puerto Rico. Most of
these
cases are in immigrants and refugees whose disease was acquired in
their
native country; however, the disease remains endemic in Hawaii, Texas,
California, Louisiana and Puerto Rico. Man is the only significant
reservoir.
Armadillos, mangabey monkeys, and chimpanzees can acquire the disease
from
humans. Epidemiologic data on leprosy in the U.S. reveal very high
ratios
of native to foreign-born leprosy patients in Texas and Louisiana in
comparison
to all other states. These are the 2 states known to have the highest
prevalences
of leprosy in wild armadillos.
TRANSMISSION:
Respiratory
and involves prolonged exposure in childhood. Only rarely have adults
become
infected.
DISEASE
IN ANIMALS:
The disease
in armadillos (Dasypus novemcinctus) is similar to the lepromatous form
in man. Infection in these animals is characterized by macrophage
infiltrates
containing a large number of bacilli. M. leprae is known to prefer the
coldest parts of the human body. For this reason, armadillos are used
as
experimental animals since their body temperature is 30-35oC. In
chimpanzees,
the disease appears as a progressive chronic dermatitis with nodular
thickening
of the skin of the ears, eyebrows, nose, and lips. Sooty mangabey
monkeys
develop lepromatous leprosy with neuropathic deformities of the
extremities,
including clawing of the digits.
DISEASE
IN HUMANS:
In lepromatous
leprosy, nodules, papules, macules and diffuse infiltrations are
bilaterally
symmetrical and usually numerous and extensive; involvement of the
nasal
mucosa may lead to crusting, obstructed breathing and epistaxis; ocular
involvement leads to iritis and keratitis. In tuberculoid leprosy, skin
lesions are single or few, sharply demarcated, anesthetic or
hyperesthetic,
and bilaterally asymmetrical; peripheral nerve involvement tends to be
severe.
DIAGNOSIS:
Demonstration
of acid-fast bacilli from skin or nasal septum scrapings.
TREATMENT:
Combination
therapy is recommended since single-drug treatment is accompanied by
emergence
of resistance. Lepromatous leprosy is treated with dapsone,
clofazimine,
and rifampin. Tuberculoid leprosy is treated with dapsone and
rifampin.
PREVENTION/
CONTROL:
Early
detection and treatment. Contact isolation for lepromatous leprosy but
not necessary for tuberculoid leprosy.
DERMATOPHILOSIS
Office
International des Epizooties
Dermatophilosis:
Manual of standards Diagnostic Tests and Vaccines 2000
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Streptotrichosis,
Mycotic Dermatitis of Sheep)
AGENT:
Dermatophilus
congolensis. An aerobic actinomycete with gram positive long branching
filaments and coccoid bodies.
RESERVOIR
AND INCIDENCE
Occurs
in temperate regions worldwide. Natural disease described in horses,
cattle,
sheep, goats, cottontail rabbits, owl monkeys, lizards &
humans.
TRANSMISSION:
The etiologic
agent is an obligate parasite that has been isolated only from lesions
in animals. Human cases have arisen from direct contact with infected
animals.
The most common means of transmission between animals is mechanical
thru
arthropod vectors. The infection may also be transmitted by means of
objects,
such as plant thorns or shears.
DISEASE
IN ANIMALS:
Circumscribed
areas of alopecia, elevated crusty papillomatous lesions, and exudative
dermatitis. **Owl monkeys may have relapsing Dermatophilosis after
apparently
appropriate antibiotic regimens. Therefore organism may persist on
pelage
of animals after resolution of lesions. In cats, the lesions differ
from
those of other domestic animals by affecting deeper tissues. In cats,
granulomatous
lesions have been found on the tongue, bladder, and popliteal lymph
nodes.
DISEASE
IN MAN:
Pustular
desquamative dermatitis.
DIAGNOSIS:
Microscopic
exam of stained material from lesions and culture.
PREVENTION\CONTROL:
1. Treatment
with antibiotics 2. Isolate affected animals 3. Protective clothing,
gloves,
personal hygiene 4. Tick control.
ERYSIPELOID
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Rosenbach's
erysipeloid, erythema migrans, erysipelotrichosis, rose disease in
swine,
diamond skin disease in swine, fish-handler's disease or fish rose in
man).
AGENT:
Erysipelothrix
rhusiopathiae (insidiosa). 22 different serotypes are recognized.
*Discovered
by ROBERT KOCH==He called it the Bacillus of Mouse Septicemia.
RESERVOIR
AND INCIDENCE
Saprophyte
in soil, water, and decaying organic matter. Pathogen in swine, lambs,
calves, poultry, fish, & wild and lab mice. *Pigs probably
represent
the most likely source of exposure in the laboratory environment.
(Natural
disease or zoonotic transmission from lab rodents has NOT been
reported.)
TRANSMISSION:
Contamination
of wounds while handling infected tissues.
DISEASE
IN ANIMALS:
Diamond
skin disease in pigs. Arthritis in sheep and swine. Cyanosis and
hemorrhages
in turkeys. Can be septicemic disease in many species.
DISEASE
IN MAN:
Disease
in humans is called Erysipeloid, and is primarily occupation related.
Inflammatory
lesions of the skin, with elevated erythematous edge; spreads
circumferentially.
Septicemia is an infrequent complication.
DIAGNOSIS:
Culture
from lesion or blood.
PREVENTION\CONTROL:
Treatment
with Penicillin Gloves when handling animals Vaccine for swine and
turkeys.
MELIOIDOSIS
Centers
for Disease Control and Prevention: Division of Bacterial and Mycotic
Diseases
Melioidosis
(Burkholderia pseudomallei)
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Pseudoglanders,
Whitmore's disease)
AGENT:
Pseudomonas
pseudomallei (Malleomyces pseudomallei, Actinobacillus pseudomallei )
--MOTILE,
Gram negative rod.
RESERVOIR
AND INCIDENCE
Normal
inhabitant of surface soil and water in Southeast Asia, and tropical
areas.
Recent studies have shown that the water of tanks in which exotic
aquarium
fishes were imported was contaminated. Occurs in wild rodents, goats,
pigs,
sheep. Also identified in Chimps, orangutans, and macaques. There is no
evidence that animals are important reservoirs, except in the transfer
of the agent to new foci. Rare in the U.S. except in drug users.
TRANSMISSION:
By inhalation
from moist soil-water reservoir, by contact with contaminated soil or
water
thru overt or inapparent skin wounds, or by ingestion of contaminated
feeds.
Can be venereal in man.
DISEASE
IN ANIMALS:
Signs
include loss of weight, swelling of joints, fever, cough, and chest
pain.
Skin lesions with fistulous tracks can develop. Emaciation and multiple
abscesses in lung, bone, viscera. A chronic draining purulent skin
lesion
in a primate is suspect. Incubation period can be 6 months to three
years.
Sheep seem especially susceptible- over 25% mortality can occur in
outbreaks.
DISEASE
IN MAN:
Clinical
disease is not common in man but subclinical disease in endemic areas
based
on serology is common. It may simulate typhoid fever or TB including
pulmonary
cavitation, empyema, chronic abscesses and osteomyelitis. High case
fatality
rate (80%) in people who do develop clinical signs.
DIAGNOSIS:
Culture
and isolation from lesions, a rising serological titer is
confirmatory.
TREATMENT:
ceftazidime.
Alternates: Chloramphenicol or Trimethoprim-sulfamethoxazole.
CONTROL:
Safe disposal
of sputum and wound discharges.
GLANDERS
Office
International des Epizooties
Glanders:
Manual of standards Diagnostic Tests and Vaccines 2000
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Farcy)
AGENT:
Pseudomonas
mallei (Actinobacillus mallei) NONMOTILE, gram negative rod
RESERVOIR
AND INCIDENCE
Disease
of equidae and rarely man. Occasionally reported in dogs, cats, sheep,
and goats. Mostly seen in Asia and Mediterranean areas, rare in North
America.
TRANSMISSION:
Spread
by contamination by infectious discharges of wounds and mucus membranes
and by ingestion.
DISEASE
IN ANIMALS AND
MAN:
Pulmonary
form: cough, nasal discharge. cutaneous form: multiple, purulent,
cutaneous
eruptions, often following lymphatics. Usually affects hind legs of
horses.
May have long periods of remission. The fatality rate in humans is 95%
if left untreated. Horses usually suffer chronic and sometimes fatal
illness.
Asses and mules usually suffer acute disease which is often fatal.
DIAGNOSIS:
Cannot
be differentiated from P. pseudomallei serologically. Specific
diagnosis
can be made only by characterization of the isolated organism.
TREATMENT:
Streptomycin
+ tetracycline or chloramphenicol + streptomycin.
PREVENTION/CONTROL:
1. Treatment
with antibiotics 2. Elimination of carrier animals 3. Gloves,
protective
clothing when handling infected animals.
TULAREMIA
Centers
for Disease Control and Prevention: National Center for Infectious
Diseases
Tularemia
(Francisella tularensis Infection)
Office
International des Epizooties
Tularemia:
Manual of standards Diagnostic Tests and Vaccines 2000
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Francis'
disease, deer-fly fever, rabbit fever, O'Hara disease)
AGENT
Francisella
tularensis, a small pleomorphic, gram-negative, nonmotile rod or
coccobacillus
that can survive several weeks in the external environment.
RESERVOIR
AND INCIDENCE
Common
often fatal septicemic disease of rabbits, squirrels, muskrats, deer,
bull
snakes, sheep, wild rodents, cats and dogs. Major reservoirs are
RABBITS,
TICKS, MUSKRATS. Has been reported in NHP's at an urban zoo. Natural
infection
in laboratory animals and zoonotic transmission from them has NOT been
reported.
TRANSMISSION:
Handling
tissue of infected animals (direct contact with UNBROKEN skin is
sufficient).
Reported human infections due to a cat bite and scratch and a NHP bite
also reported. transmitted by biting insects inhalation,
ingestion.
DISEASE
IN ANIMALS:
Clinical
signs usually occur alongside heavy infestation with ticks, and include
sudden high fever, anorexia and stiffness, eventually leading to
prostration
and death. In sheep, pregnant ewes may abort. Affected dogs have soft
nodular
swellings under the skin. Miliary foci of necrosis occur in the liver,
spleen and lymph nodes. Severe lesions in the lung involve widespread
consolidation
with edema and pleurisy.
DISEASE
IN MAN:
Fever,
headache, and nausea begin suddenly, and a local lesion-a
papule-develops
and soon ulcerates. Regional lymph nodes may become enlarged and tender
and may suppurate. The local lesion may be on the skin of an extremity
(ulceroglandular disease) or in the eye. Pleuropulmonary disease may
develop
from hematogenous spread or may be primary after inhalation. Following
ingestion of infected meat or water, an enteric (typhoidal) form may be
manifested by enteritis, stupor, and delirium. In any type of
involvement,
the spleen may be enlarged and tender and there may be nonspecific
rashes,
myalgias, and prostration. A case fatality rate of 5-10% mainly from
the
typhoidal or pulmonary form exists.
DIAGNOSIS:
Culture
(requires specialized laboratory and dangerous, therefore, not
recommended)
A positive agglutination test (>1:80) develops in the second week
after
infection and may persist for several years.
TREATMENT
IN MAN:
Streptomycin
+ tetracycline. Chloramphenicol may be substituted for
tetracycline.
PREVENTION\CONTROL:
Wear impervious
gloves while handling animals or tissues cook the meat of wild rabbits
and rodents thoroughly vaccine available for high risk personnel avoid
bites of flies, mosquitos, and ticks and avoid drinking, bathing,
swimming
in untreated water in endemic areas.
STREPTOCOCCOSIS
Centers
for Disease Control and Prevention: National Center for Infectious
Diseases
Streptococcus
pneumoniae Infection
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
AGENT:
The causative
agents are various streptococci species, including Streptococcus suis
and
S. zooepidemicus.
RESERVOIR
AND INCIDENCE
Pigs are
the reservoir of S. suis.
TRANSMISSION:
Humans
are infected with S. suis by handling infected meat. S. zooepidemicus
has
occurred in persons in direct contact with domestic animals and from
drinking
raw milk.
DISEASE
IN ANIMALS:
S. suis
epizootics may occur in pigs with high mortality, heralded by signs of
meningitis including depression, fever, incoordination and paralysis.
Suppurative
arthritis may occur. More usually the disease is subclinical. S.
zooepidemicus
may cause mastitis in cattle.
DISEASE
IN MAN:
S. suis
causes fever and occasionally meningitis. S. zooepidemicus may cause
upper
respiratory tract symptoms, cervical adenitis, pneumonia, endocarditis
and nephritis. A fatality rate of 8% has been reported for S. suis,
with
residual deafness in a high proportion of survivors.
DIAGNOSIS:
Isolation
and culture.
TREATMENT:
Benzathine
Penicillin G. For persons allergic to penicillin, erythromycin is an
effective
alternative. However, increasing reports of resistance from Europe
threatens
its clinical utility.
PREVENTION/CONTROL:
Exercise
caution in handling pig meat. Dress all wounds to avoid contamination.
Pasteurize milk.
RAT
BITE FEVER
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Streptobacillary
fever, Haverhill fever, epidemic arthritic erythema, sodoku)
AGENT:
Gram negative,
pleomorphic bacillus. Two different agents can cause disease: 1.
Streptobacillus
moniliformis (Haverhill Fever) *Named after a 1926 outbreak in
Haverhill,
Mass. attributed to contaminated milk. 2. Spirillum minus
(Sodoku).
RESERVOIR
AND INCIDENCE
Present
in the oral and respiratory passages of a large number of asymptomatic
rodents, including Rats and Mice. Incidence of disease appears to be
low.
Historically, wild rat bites and subsequent illness (usually small
children)
relate to poor sanitation and overcrowding.
TRANSMISSION:
Man infected
by bite of infected rodent or via contaminated milk or food.
DISEASE
IN ANIMALS:
Rats:
inapparent infection Mice: acute, systemic, fatal disease in
immunologically
inexperienced mice. Surviving mice (or if endemic disease), exhibit
suppurative
polyarthritis, swelling and loss of digits or limbs.
DISEASE
IN MAN:
Acute
febrile disease following bite from a rodent. Can see inflammation,
lymphadenopathy,
and nonspecific signs. May exhibit rash on extremities, often soles and
palms. May see arthritis with S. moniliformis. Incubation period
variable:
S. moniliformis: hours to 1 to 3 days S. minus: 1 to 6 weeks Symptoms
usually
resolve spontaneously. Complications, if not treated promptly, lead to
pneumonia, hepatitis, enteritis, endocarditis with a 10% fatality
rate.
DIAGNOSIS:
Culture:
S. moniliformis requires 10 to 20% horse or rabbit serum and reduced
oxygen
tension. S. minus- won't grow in vitro. Must inoculate culture
specimens
into lab animals and use dark field microscopy.
TREATMENT:
Treat
with procaine penicillin G or tetracycline HCl. Give supportive and
symptomatic
measures as indicated.
PREVENTION/CONTROL:
Bacteriologic
monitoring Proper treatment of rodent bites
PASTEURELLOSIS
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Shipping
or transport fever, hemorrhagic septicemia)
AGENT:
Pasteurella
multocida, small, nonmotile, polymorphic, gram-positive bacilli.
RESERVOIR
AND INCIDENCE
Inhabits
the oral cavity and upper respiratory tract of many animals (Rabbits,
rodents,
dogs, cats, mice, birds, swine). Dogs and cats are frequently healthy
carriers.
TRANSMISSION:
All animals
and birds may be colonized by pasteurellas, and human infection occurs
by wound infection from bites or scratches. Animal-to-animal
transmission
may occur by ingestion and inhalation. 1986 case report of meningitis
in
a woman who kissed her dog (cultured positive for organism) and also
had
dental caries which was considered to be the route of infection.
DISEASE
IN ANIMALS:
can cause
acute pneumonia or septicemic disease in many species. May cause
chronic
infection of upper respiratory and middle ear especially in the
rabbit.
DISEASE
IN MAN:
Local
inflammation occurs around the bite or scratch, possibly leading to
abscess
formation with systemic symptoms.
TREATMENT:
Penicillin,
tetracycline, or cephalosporin.
PREVENTION/CONTROL:
Proper
treatment of bite Protective clothing (mask,gloves) Euthanize
aggressive
dogs and cats. Vaccinate cattle and sheep.
CLOSTRIDIAL
INFECTIONS
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Clostridial
myositis: black leg, malignant edema, gas gangrene. Enterotoxemia:
pulpy
kidney, struck, lamb dysentery, braxy. Tetanus: lockjaw).
AGENT:
Clostridium
tetani (horses)--tetanus Clostridium perfringens (cattle, sheep)--gas
gangrene
Clostridium septicum (cattle) malignant edema.
RESERVOIR
AND INCIDENCE
Clostridia
are normal intestinal flora and also survive by spores in the
soil.
TRANSMISSION:
Infection
may be by contamination of deep, penetrating wounds to cause tetanus,
by
ingestion of preformed toxin or spores which vegetate in the digestive
tract to cause enterotoxemia, or by ingestion of spores which are
carried
by the blood to muscles where they remain dormant until activated by
trauma
to produce necrotizing myositis. C. perfringens food poisoning is due
to
spore contamination of foods which survive heating to vegetate in
unrefrigerated
conditions. Neonatal tetanus in humans is frequently caused by
contamination
of the umbilicus.
DISEASE
IN ANIMALS:
Tetanus:
as in humans. In myositis (black leg) cases a limb is still and painful
with crepitus on palpation. Signs of toxemia. Rapidly fatal. C.
chauvoei,
novyi, and septicum toxins produce massive muscle necrosis, often with
edema and SC gas formation. C. perfringens causes a variety of profound
toxemias with cloudy swelling of parenchymatous organs and excess
fluids,
often bloodstained in serous cavities.
DISEASE
IN MAN:
Tetanus:
painful toxic contractions of muscles and trismus. The case fatality
rate
for tetanus is 30-90% even when treated. Gas gangrene: fever, toxemia,
painful edema spreading from the edges of wounds, interstitial
emphysema,
neck stiffness. Food poisoning: vomiting and diarrhea of a few days'
duration.
TREATMENT:
Myositis:
penicillin, adequate surgical debridement and exposure of infected
areas.
Tetanus: immune globulin, penicillin, mechanical ventilation. Spasms
are
controlled with chlorpromazine or diazepam combined with a
sedative.
PREVENTION/CONTROL:
Immunization
with toxoids (good for 10 years), proper treatment of wounds. Good food
hygiene is essential. In animals, prevent wound contamination during
lambing,
shearing, castration and docking.
CAPNOCYTOPHAGA
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
AGENT:
Capnocytophaga
canimorsus (formerly Dysgonic fermenter-2), a recently described
aerobic,
gram negative bacillus with unusual fermentation pattern.
RESERVOIR
AND INCIDENCE
Found
as part of oral flora of normal dogs and cats. C. canimorsus has been
isolated
from the mouths of 24% and 17% of normal dogs and cats respectively.
Serious
infections in man are most commonly reported in splenectomized or
immunocompromised
people, alcoholics, or persons who have chronic respiratory disease.
More
than 40 cases reported, many fatal, since first reported in 1976.
TRANSMISSION:
Contact,
bite or scratch from dog or cat
DISEASE
IN MAN:
Can lead
to cellulitis and overwhelming bacteremia, meningitis, endocarditis,
septic
arthritis, and DIC. The organism appears to have an affinity for the
eye,
causing angular blepharitis and severe keratitis. Accidental corneal
inoculation
occurred during a tooth extraction in a Poodle causing severe
refractory
keratitis in a veterinarian. The predisposition of the cornea to
infection
may be due to its avascularity and to the low concentrations of
immunoglobulins
and complement components in the tissue. Most serious disease and
fatalities
have occurred in splenectomized people. Case fatality rates of 4-27%
have
been reported.
DIAGNOSIS:
History,
clinical signs, and culture. ORGANISM IS SLOW GROWING. May require 8
days
of incubation. Micro exam of blood smear or buffy coat with gram stain
to detect organisms.
PREVENTION/CONTROL:
Awareness,
especially of high risk individuals Treatment of bite wounds,
Penicillin
G. (Treatment of high risk people even without sign of infection
recommended).
PSITTACOSIS
Centers
for Disease Control and Prevention: Division of Bacterial and Mycotic
Diseases
Psittacosis
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Ornithosis,
Parrot Fever, Chlamydiosis)
AGENT:
Obligate,intracellular
organism with a unique development cycle and worldwide distribution
Genus
Chlamydia has only four species, many strains 1. Chlamydia trachomatis-
humans, mice (Zoonotic potential not known) 2. Chlamydia psittaci-
BIRDS,
Mice, g. pig, rabbits, cats, frogs, ruminants 3. Chlamydia pneumoniae-
humans 4. Chlamydia pecorum- ruminants.
RESERVOIR
AND INCIDENCE
The mammalian
strains appear to be a zoonotic problem only rarely. 2 cases of human
conjunctivitis
reported from close association with cats with chlamydial pneumonitis
and
conjunctivitis. Birds are the main reservoir of human infection,
however,
25% of human cases have no history of avian contact. Ovine strains may
infect pregnant women.
TRANSMISSION:
Inhalation;
dry feces produce highly infective aerosols Direct contact with feces
or
respiratory secretions May survive in dust for several months.
DISEASE
IN ANIMALS:
There
are many strains of C. psittaci which produce a diverse disease
spectrum
in animals, e.g., conjunctivitis, air sacculitis, pericarditis,
hepatitis,
meningoencephalitis, enteritis, urethritis, arthritis, and endometritis
with abortion. G.I. infection results in enteric shedding of the
organism.
Latency - Well recognized feature of Chlamydia infection, i.e., the
organism
can cause inapparent infection or fulminant infection in the same host.
In clinically healthy birds, stress can precipitate clinical signs and
shedding of the organism.
DISEASE
IN MAN:
Asymptomatic
or clinical disease after 1-2 week incubation period. Fever, chills,
myalgia,
anorexia, headache, nonproductive cough. Pneumonitis or atypical
pneumonia
may be present. May see a toxic or septic form with hepatosplenomegaly,
hepatitis, meningoencephalitis and cardiac involvement with
endocarditis.
Ovine chlamydial infection in pregnant women is life-threatening,
causing
late abortion and neonatal death and disseminated intravascular
coagulation
in the mother.
DIAGNOSIS:
Fecal
culture (rarely successful) serology (CF, IFA) [Note: African Grey
Parrot,
cockatiel, and budgie may remain serologically negative despite active
infection.] ELISA-based tests for antigen in feces has proven
reliable.
TREATMENT:
Tetracycline
or Erythromycin.
PREVENTION/CONTROL:
Treatment
with tetracycline Introduce birds into colony from psittacosis-free
flocks
or use chlortetracycline chemoprophylaxis. Protective clothing (masks,
gowns, gloves). Wild caught birds should be placed on chlortetracycline
during quarantine. In sheep, keep flocks closed or vaccinate annually.
Isolate aborting ewes until discharges cease.
BLASTOMYCOSIS
Centers
for Disease Control and Prevention: Division of Bacterial and Mycotic
Diseases
Blastomycosis
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
SYNONYMS:
North
American blastomycosis, Chicago disease, Gilchrist's disease.
ETIOLOGY:
Blastomyces
dermatitidis, a dimorphic fungus existing in mycelial form in cultures
and as a budding yeast in the tissues of infected mammals.
GEOGRAPHIC
DISTRIBUTION:
The disease
has been observed in the United States, eastern Canada, Zaire,
Tanzania,
South Africa, and Tunisia. Autochthonous cases may have occurred in
some
Latin American countries.
THE
DISEASE IN MAN:
The incubation
period is not well known; it possibly extends to several weeks or
months.
Blastomycosis is a chronic disease that principally affects the lungs.
The respiratory symptomatology initially resembles influenzas purulent
or bloody expectoration, weight loss, and cachexia, in addition to
fever
and cough, may develop later. If the infection remains localized, it
can
become asymptomatic. When it disseminates, it can cause subcutaneous
abscesses
as well as localized infections in several organs. Death frequently
results
in cases of untreated disseminated infection. The cutaneous form is
commonly
secondary to the pulmo-nary and is characterized by an
irregular-shaped,
scabby ulcer that has raised borders and contains minute abscesses.
Lesions
develop on exposed parts of the body.
THE
DISEASE IN ANIMALS:
The highest
incidence is observed in dogs around 2 years of age. The symptoms
consist
of weight loss, chronic cough, dyspnea, cutaneous abscesses, fever,
anorexia,
and sometimes blindness. The lesions localize in the lungs, lymph
nodes,
eyes, skin, and joints and bones. Of 47 clinical cases recently
described,
72% occurred in large males. There were lesions of the respiratory
tract
in 85% of the cases.
SOURCE
OF INFECTION
AND MODE OF TRANSMISSION:
The reservoir
is environmental, probably the soil, but the ecologic biotope has not
been
determined. Transmission to man and to animals is effected by aerosols;
the fungal conidia are the infecting element. Persons at highest risk
are
those having the most contact with the soil. Dogs most frequently
infected
are sporting and hunting breeds.
ROLE
OF ANIMALS IN THE
EPIDEMIOLOGY OF THE DISEASE:
None.
It is a disease common to man and animals. Cases of transmission from
individual
to individual (man or animal) are not known.
DIAGNOSIS:
Diagnosis
is based on direct microscopic examination of sputum and material from
lesions, on isolation of the agent in culture media, and on examination
of histologic preparations. B. dermatitidis grows well in Sabouraud's
culture
medium or other adequate median it is most distinctive in its sprouting
yeast form, and therefore the inoculated medium should be incubated at
37oC, since at ambient temperature the mycelial form of the fungus is
obtained.
B. dermatitidis in its yeast form (in tissues or cultures at 37oC) is
characterized
by a single bud attached to the parent cell by a wide base, from which
it detaches when it has reached a size similar to the parent cell. In
contrast,
Paracoccidioides brasiliensis, the agent of paracoccidioidomycosis
("South
American blastomycosis"), has multiple buds in the yeast phase.
Serologic
tests in use are complement fixation and gel immunodiffusion; the
latter
gives better results. It should be borne in mind that cross-reactions
with
Histoplasma and Coccidioides may occur. At present, the intradermal
test
is considered to have no diagnostic value.
TREATMENT:
Humans.
Itraconazole, 100-200 mg/d orally, is now the therapy of choice for
nonmeningeal
disease, with a response rate of over 70%. Amphotericin B is given for
treatment failures or cases with central nervous system involvement.
Follow-up
for relapse should be regularly made for several years so that therapy
may be resumed or another drug instituted. Animals. Rare primary
cutaneous
disease may persist for months; these lesions should be removed
surgically
since blastomycosis responds poorly to therapy. Amphotericin B is
considered
the drug of choice, but treatment is of little avail once the disease
is
disseminated. The combination of amphotericin B and ketoconazole has
been
suggested to reduce the rate of relapse.
CONTROL:
As long
as the ecologic biotope remains poorly defined, practical prevention
methods
cannot be established.
CAT
SCRATCH DISEASE
Centers
for Disease Control and Prevention: National Center for Infectious
Diseases
Cat
Scratch Disease (Bartonella henselae Infection)
Disease
Overview:
Institutional
Animal Care and Use Committee, University of California, Santa
Barbara.
(Cat
Scratch Fever, Benign Lymphoreticulosis, Benign nonbacterial
Lymphadenitis,
Bacillary Angiomatosis, Bacillary Peliosis Hepatis)
AGENT:
Controversial,
it is not currently possible to definitively name the causative agent
responsible
for CSD. Felt to be either Afipia felis, a gram-negative rod or
Rochalimaea
henselae and Rochalimaea quintana. Both are members of class
Proteobacteria
and both are intracellular parasitic bacteria.
RESERVOIR
AND INCIDENCE
Associated
with domestic cats throughout the USA, and worldwide. Over 6000 cases
annually.
Seen more often in men than in women . Have seen clusters of infection
within families within a 2 to 3 week period, suggesting that shedding
by
cats may occur periodically. Other sources of infection have included
scratches
from other species including dogs, squirrels, and goats and from wounds
induced by crab claws, barbed wire, and plant material.
TRANSMISSION:
90% of
patients have been exposed to a cat. 75% of these have been bitten,
scratched,
or licked. Most affected individuals are <20 years of age. 75-80% of
the cases of CSD are diagnosed between September and February with a
peak
incidence in December. 4 to 6% of the general population and 20% of
veterinarians
have positive skin test reactions to CSD antigen.
DISEASE
IN ANIMALS:
Subclinical
DISEASE
IN MAN:
Different
distinct syndromes exist:
Typical
CSD
A primary
lesion, most common on neck or extremities, will develop in 50% of the
cases and appear approximately 10 days after a bite or scratch. A
pustule
persists for 1-2 weeks. 10-14 days after the lesion appears,
lymphadenopathy
develops and usually regresses within 6 weeks. 30-50% of the enlarged
nodes
become suppurative. Of the approximately 65% who develop systemic
illness,
fever and malaise are the symptoms most often noted. The disease is
usually
benign and most patients recover spontaneously without sequelae within
2-4 months. Many unrecognized cases probably occur. Disease appears to
confer lifelong immunity.
Atypical
CSD
The atypical
forms of CSD, which constitute 11% of all cases, are extremely varied.
The most common, representing 6% of all cases, is Parinaud's
oculoglandular
syndrome (POGS), or granulomatous conjunctivitis with preauricular
adenopathy.
Other, atypical presentations include tonsillitis, encephalitis,
cerebral
arteritis, transverse myelitis, radiculitis, granulomatous hepatitis
and/or
splenitis, osteolysis, atypical pneumonia, hilar adenopathy, pleural
effusion,
erythema nodosum, erythema annulare, maculopapular rash,
thrombocytopenic
purpura, and breast tumor. Bacillary Angiomatosis Dermal BA presents in
several ways. The commonest form is an enlarging red papule with some
resemblance
to a cranberry, often with a collarette of scale and sometimes with a
suggestion
of surrounding erythema. This type of lesion may be mistaken for
pyogenic
granuloma, unless fairly deep biopsy specimens are examined. These
lesions
begin as small papules and enlarge, occasionally becoming several
centimeters
in diameter and rarely ulcerating. They may be single or quite
numerous.
Another form of dermal BA is a deeper, subcutaneous nodule that appears
flesh-colored and may be either fixed to subcutaneous tissues or freely
mobile. Rarely BA may present as a dermal plaque. BA has been reported
to occur in every organ system, including the brain, and is often
difficult
to differentiate from mycobacterial and fungal infections or malignancy
without the use of biopsy. It is unclear if the personality changes,
ranging
from frank psychosis to depression, that have been described in
association
with BA represent CNS involvement or a neurotoxic product of this
infection.
Bacillary Peliosis Hepatis BPH, a vasoproliferative condition involving
the liver of HIV-infected patients, is characterized by a proliferation
of cystic blood-filled spaces surrounded by fibromyxoid stroma in which
one can see bacteria similar to those seen in BA. Clinically these
patients
may or may not have visible bacillary angiomas. Their symptoms usually
include fever, weight loss, and abdominal pain or fullness. Physical
exam
may reveal organomegaly. Laboratory studies usually demonstrate
elevation
of alkaline phosphatase and ç-glutamyltransferase levels out of
proportion to those of aminotransferase and bilirubin.
DIAGNOSIS:
The sedimentation
rate is elevated, the white blood cell count normal, and the pus from
the
nodes is sterile. ID skin testing with antigen prepared from the pus is
positive. Excisional biopsy, usually performed to exclude lymphoma,
confirms
the diagnosis.
TREATMENT:
For CSD:
Rifampin, ciprofloxacin, gentamycin, and trimethoprim-sulfa. Aspiration
of suppurating nodes is recommended for relief of pain. Symptoms
resolve
without treatment in 2-4 months. BA and BPH respond to erythromycin,
rifampin,
or doxycycline. Therapy must be continue for 4-6 weeks to avoid
relapse.
PREVENTION/CONTROL:
Education.
Wash hands after handling cat. Wash cuts and scratches promptly and
don't
allow cat to lick open wound.
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