Feb. 12, 2004
Dr. Greg Vercellotti discussed avian flu on the Feb. 12
KARE-11 Today Show.
Q: What is avian flu?
Dr. Vercellotti:
The avian flu making the news is a strain of Influenza A that infects birds,
primarily waterfowl and domestic poultry. This family of viruses causes human
flu as well.
There are 15 strains of Influenza A that infect birds, but
only two are considered to be pathogenic, meaning that they cause severe
symptoms and even death. Thirteen strains are classified as low pathogenic.
Wild birds like ducks commonly carry these influenza
strains, but they typically do not get sick. These wild birds can infect
domestic turkeys and chickens, which can become seriously ill and even die.
Researchers think one of these highly pathogenic strains has
infected millions of birds in Asia and so far 18 people in 10 countries have
died. Millions of birds have been slaughtered as a safety precaution. They
believe the outbreak began October 2003 in Vietnam.
Sick chickens carry the disease in saliva, nasal secretions,
and fecal matter. Humans seem to be able to catch the disease by coming into
contact with these fluids containing the virus. Researchers think the human
cases involve people catching the flu from birds, though scientists are
investigating the possibility that two cases in Vietnam involved
person-to-person transmission.
Human symptoms include fever, chills, spotty muscle aches,
and cough, just like any other influenza. So far, the disease has little or no
ability to be passed from person-to-person. However, scientists fear if the
virus changes and does pass from person-to-person, it could create a worldwide
epidemic like the Spanish influenza epidemic of 1918-1919, which killed 40
million to 50 million people. At this time, such a scenario appears unlikely.
Key Points
- So
far, most of the outbreaks have occurred in Asia, though authorities in
Delaware say there is an isolated outbreak of a different strain of avian
flu in the central part of the state. No human cases have been reported in
the United States.
- There
have been previous outbreaks of avian flu in the United States. A 1983
outbreak of a related avian influenza in Pennsylvania led to the slaughter
of 17 million birds.
- One
of the first possible cases of this same strain of influenza involving
humans is believed to have occurred in Hong Kong in 1997 when six people
died out of 18 reported cases. Officials believe the outbreak was halted
by the slaughter of 1.5 million birds in three days. The Netherlands
experienced an outbreak in 2003; 28 million birds were slaughtered and one
person died.
- Researchers
are concerned that the virus could jump from one species to another.
That could have serious ramifications. Why?
1.
Influenza is made up of eight short segments of genetic
material called RNA. That makes it easy for the virus to mutate, which partly
explains why its virtually impossible to come up with a cure for the flu.
Researchers fear once the bird flu gets into humans, it could mutate, giving
rise to a more deadly strain.
- The
subtype of virus has already proven it could mutate rapidly and has a
propensity for acquiring genes from viruses in other animal species.
- Its
caused severe disease in humans already, and
- Its
spread rapidly.
- All this leads researchers to caution that this could
lead to a pandemic, or worldwide epidemic.
The Health Talk & You Web site provides general information on health-related
topics. The information is for general health education purposes only and
is not intended to provide medical advice. Specific advice on diagnosing or
treating a health care problem should be obtained from a health care provider.
Visit University of Minnesota Physicians
for a list of medical specialties at the University of Minnesota, or call
612-672-7422.
