- ATLANTA (AP) - As if West
Nile virus wasn't bad enough, now U.S. health officials are on the lookout
for another mosquito-bourne disease, fearing it could become a permanent
part of the American landscape if it entered the country.
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- Rift Valley fever, which originated in Africa, is the
only disease at the top of both human health and agriculture lists of dangerous
diseases.
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- The virus can kill people, with a near 1 percent mortality
rate, making it deadlier than West Nile. But Rift Valley poses a greater
threat to cattle and sheep.
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- It kills up to 30 percent of the livestock it infects
and if it were found in animals here, it would probably prompt livestock
bans by other countries.
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- "This is not a disease that occurs here now, but
we want to make sure people are aware of the signs and symptoms,"
said Dr. Thomas Ksiazek, chief of the special pathogens branch of the U.S.
Centers for Disease Control and Prevention. "The medical and public
health community need to be mindful of it."
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- Most people get a flu-like illness when infected. Some
may develop serious symptoms, including liver or kidney disease, Ksiazek
said.
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- About 14 percent of those seriously ill with Rift Valley
fever in previous outbreaks died. West Nile kills about 10 percent of those
with serious complications, such as brain inflammation.
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- The virus is worrisome because at least 30 species of
mosquitoes are capable of carrying it from cattle or sheep to humans, far
more than the kind of mosquitoes that can carry West Nile. People also
can catch it by handling the blood or fluids of an infected animal.
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- Scientists said that Rift Valley fever was being researched
as a possible weapon during the Cold War and showed promise because of
its stability in an aerosol form.
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- Despite the concern, health and agricultural officials
have been slow to prepare for Rift Valley, said Dr. Corrie Brown, a professor
of veterinary pathology at the University of Georgia and a member of the
U.S. Secretary of Agriculture's advisory committee for animal and poultry
diseases.
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- "I think people weren't very worried about it until
we started to think about agri-terror," Brown said.
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- The disease could appear here as mysteriously as West
Nile, which first showed up as the culprit in the unexplained deaths of
birds in New York in 1999.
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- The virus was first identified in a 1930 sheep outbreak
in Kenya's Rift Valley in eastern Africa. For the next 70 years, it remained
on the continent, emerging for the first time outside of Africa in outbreaks
in Saudi Arabia and Yemen in 2000. In those cases, about 100 people died
and 800 became ill.
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- Luckily, the virus seems to have disappeared, and there
have been no new cases there since 2001.
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- Rift Valley fever is one of several emerging viruses
being studied by the University of Texas Medical Branch in Galveston, Texas.
One focus is better vaccines, since there is no approved vaccine for people
or livestock in case of an outbreak, Ksiazek said. The military developed
a vaccine that has been approved for testing in people.
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- "It would really be hard to control this without
a vaccine," said Dr. C.J. Peters, director of biodefense at UTMB in
Galveston.
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- http://apnews.myway.com/article/20040623/D83CJL5O0.html
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