|
Updates: 5 May 2009:
Study materials:
In the 1918–1919 pandemic, a first or spring wave began in March
1918 and spread unevenly through the United States, Europe, and
possibly Asia over the next 6 months (Figure 1). Illness rates
were high, but death rates in most locales were not appreciably
above normal. A second or fall wave spread globally from September
to November 1918 and was highly fatal. In many nations, a third
wave occurred in early 1919 (21). Clinical similarities
led contemporary observers to conclude initially that they were
observing the same disease in the successive waves. The milder
forms of illness in all 3 waves were identical and typical of influenza
seen in the 1889 pandemic and in prior interpandemic years. In retrospect,
even the rapid progressions from uncomplicated influenza infections
to fatal pneumonia, a hallmark of the 1918–1919 fall and winter
waves, had been noted in the relatively few severe spring wave cases.
The differences between the waves thus seemed to be primarily in
the much higher frequency of complicated, severe, and fatal cases in the
last 2 waves. -- CDC: 1918 Influenza: the Mother of All Pandemics:*Armed
Forces Institute of Pathology, Rockville, Maryland, USA; and †National
Institutes of Health, Bethesda, Maryland, USA
Policy Progress during the last 24 hours:
The head of the World Health Organization warned in a newspaper interview
that swine flu may re-emerge stronger than ever even if the current outbreak
appears to be declining. Margaret Chan told Britain's Financial Times
that an apparent decline in mortality rates did not mean the pandemic
was coming to an end and a second wave may strike "with a vengeance."
"If it's going to happen it would be the biggest of all outbreaks the world
has faced in the 21st century," the business daily quoted her as saying.
-- WHO chief warns of second wave of swine flu, AFP, 4
May 2009.
Crucial global surveillance of animal disease could be revised to
include swine influenza in pigs because of its potential risk to human health,
a World Health Organisation expert said Monday.... Phase one of the WHO
pandemic flu alert system adopted just four years ago should be triggered
when a potentially dangerous virus is detected among animals but no infections
are reported in humans. With the new swine flu virus, the WHO jumped straight
into phase four very swiftly after the outbreak was first announced in Mexico
and the United States, because sustained human to human spread had been
established. -- Permanent watch on pigs may be needed for flu, AFP,
4 May 2009.
ROME, May 4 (Xinhua) -- The Food and Agriculture Organization (FAO) said
on Monday that national authorities and farmers should carefully monitor
pigs and investigate any possible occurrences of influenza-like symptoms
in domestic animals. -- FAO urges countries to closely monitor A/H1N1 in pigs:
www.chinaview.cn, 2009-05-05 08:01:42
Related:
|
