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SWINE FLU
Swine influenza (also called swine flu, hog flu, and pig flu) is an infection
of a host animal by any one of several specific types of microscopic organisms
called "swine influenza virus".
The 2009 outbreak of Influenza A virus subtype H1N1 was identified in April
2009 as an epidemic of a new strain of influenza virus, commonly referred to as
swine flu. It was thought to be a mutation (reassortment) of four known strains
of influenza A virus subtype H1N1: one endemic in humans, one endemic in birds,
and two endemic in pigs (swine).[50] The outbreak began in Mexico, where early
reports indicated a surge of cases that had already killed at least 81 people by
April 26. As a result, the U.N.'s World Health Organization (WHO), along with
the U.S. Centers for Disease Control and Prevention (CDC), expressed concern
that this could become a worldwide flu pandemic, with WHO raising its alert
level to Phase 5 out of the six maximum, indicating that a pandemic was
"imminent".
According to the CDC, it was not yet clear how serious this new virus actually
was compared with other influenza viruses, although on May 26 they stated that
new cases in the U.S. had probably peaked, and most cases throughout the world
have so far been mild relative to "seasonal flus."[51] But because this is a new
virus, most people do not have immunity to it, and illness may eventually become
more severe and widespread in different demographic and population groups as a
result. The H1N1 flu mainly spreads in the same way that regular "seasonal
influenza" spreads, which is through the air from coughs and sneezes or touching
those infected. It cannot be transmitted from eating cooked pork or by being in
close contact with pigs.[52]
There was no vaccine available to prevent infection as of June 2009[update],
although companies were developing one for availability in late July or August.
There was concern that the virus could mutate again over the coming months,
leading to a new and potentially more dangerous flu outbreak later in the year,
and a vaccine that would be less effective in preventing its spread. Health
officials in the U.S. pointed out that the "terrible experience" of the 1918 flu
pandemic, which killed approximately 600,000 in the United States alone, was
preceded by a mild "herald" wave of cases in the spring. [53]
As of June 1, the virus had spread to more than 66 countries, however over 80%
of reported deaths had taken place in Mexico. This led to speculation that
Mexico may have been in the midst of an unrecognized epidemic for months prior
to the current outbreak, thereby showing a fatality rate that was much higher
than it would have been if earlier cases had been counted. According to the CDC,
the fact that the flu's infection activity is now monitored more closely may
also help explain why more flu cases than normal are being recorded in many
countries. With the southern hemisphere soon entering its winter flu season, the
CDC, as part of WHO's global surveillance network, would help monitor cases in
that region. It has supplied test kits to laboratories in more than 100
countries, and would be providing technical assistance to other governments.
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