flu was in the news earlier this year with an outbreak in Asia
and cases reported in the United States. Avianflu is caused
by influenza A viruses that primarily infect bird populations
worldwide. Certain strains of avian flu arehighly contagious
and possibly deadly for some birds, especially domesticated
chickens. The virus is spreadamong susceptible birds when they
have contact with nasal, respiratory or fecal material from
infected birds. There are several subtypes of avian influenza
viruses but, BirdFlu.org reports that only three subtypes are
known to cause severe illness in humans: H5N1, H9N2 and H7N7.
Influenza A subtypes are given names based on two surface proteins,
Hemagglutinin and Neuraminidase, thus the strain is identified
recent outbreak of avian flu in Asia was attributed to the H5N1
strain, which can cause illness and even death in humans. However,
the isolated outbreaks in the United States were not related
to the Asian H5N1 outbreak.The strains recently identified in
the United States were H5N2, H7N2 and H7N3. These strains are
not considered fatal to humans though they can be devastating
to domestic chicken populations.
The first instance of direct bird-to-human transmission of H5N1
occurred during an outbreak of avian influenza among poultry
in Hong Kong in 1997, according to reports from the Centers
for Disease Control (CDC). The virus caused severe respiratory
illness in 18 people and resulted in six deaths.
cases during the latest outbreak occurred only after direct
contact with infected chickens or their drop-pings. However,
in rare circumstances, people who catch the virus from birds
can pass it on to other humans,although the disease is generally
milder in those who caught it from an infected person rather
than from infected birds.
of avian influenza in humans range from typical influenza-like
symptoms such as fever, cough, sore throat and muscle aches
to eye infections, pneumonia, acute respiratory distress, viral
pneumonia and other severe and life-threatening complications.
a way of preventing a major outbreak of avian flu, the World
Health Organization recommends that all infected or exposed
flocks of chickens and other birds be killed to help prevent
further spread of the virus and reduce opportunities for human
infection. Rapid detection and elimination of the avian flu
strain is essential. People working with potentially infected
bird populations need take precautions to prevent disease transmission.
traveling to areas affected by avian flu need to avoid poultry
farms, live animal markets and contact with areas contaminated
with animal or bird excrement.
more information on avian flu strains and current outbreak information,
visit the Centers for Disease Controversies at www.cdc.gov/flu,
and the University of Texas Health Science Center at Houston’s
online magazine at http://publicaffairs.uth.tmc.edu/hLeader/archive/