West Nile Virus Resurfaces in 24 States, CDC Says
ATLANTA (Reuters) - U.S. health officials reported on Monday that the West Nile virus had resurfaced in two dozen states, but they stopped short of predicting another record outbreak of the deadly mosquito-borne disease.
West Nile has been detected in birds, horses and mosquitoes in at least 24 states so far this year, according to the U.S. Centers for Disease Control and Prevention, which has tracked the virus since it first emerged in the United States in 1999.
No human cases have been reported this year.
Dr. Stephen Ostroff, deputy director of the CDC's national center for infectious diseases, said it was unclear whether the mosquitoes responsible for spreading the virus would pose as much of a health risk to the public as they did in 2002.
"Whether or not this season will be a replay of last year is a little early to say," Ostroff said. He did, however, advise people to start draining pools of water where mosquitoes breed and to wear protective clothing and repellents outside.
There were 4,156 cases of West Nile, including 284 deaths, in the United States last year, according to the CDC. The outbreak was the largest since the virus first appeared in the Western Hemisphere four years ago.
During the 2002 outbreak, CDC officials confirmed the first known cases in which West Nile was transmitted through organ transplants and blood transfusions. The possibility the virus could be spread through breast milk or sexual contact also has been studied.
Although most people who contract West Nile have no symptoms and those who do normally suffer little more than flu-like illness, it is believed they still can carry small amounts of the virus in their blood for several days.
It is estimated that up to 200,000 Americans may have been exposed to West Nile since 1999, when it killed seven people in the New York City borough of Queens. An estimated 4.5 million Americans receive blood or blood products annually.
The prospect that the virus could spread through the nation's blood supply prompted officials with the Food and Drug Administration, blood banks and laboratories to work this past winter on a way to screen blood for the virus.
Dr. Jesse Goodman, director of the FDA's Center for Biologics, Evaluation and Research, said on Monday that two new tests would be available for use in high-risk areas this summer.
"We're still very concerned about this and we'll have to see how these tests perform," Goodman said