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As West Nile virus creeps toward California, an unlikely warrior could provide the first line of defense: the chicken. The familiar fowl make irresistible targets for mosquitoes. Unlike crows, chickens don´t get sick from West Nile. But they do produce telltale antibodies to the virus. So in test coops scattered across the state, more than 2000" sentinel chickens" submit to frequent blood tests. When antibodies do turn up, California health officials will know that the inevitable has occurred:the West Nile epidemic will have swept the country.
Last week alone, more than 100 new human cases of West Nile were reported. The virus was detected as far west as Colorado and Wyoming, infecting 371 and killing 16 people in 20 states plus the District of Columbia. This year West Nile appeared earlier in the mosquito season--mid-June in- stead of August--and claimed younger victims;the average age dropped from 65 to 54 Federal health officials are still trying to figure out why, but say they may be finding more West Nile pre- cisely because they´re on the lookout for it. As Dr. Julie Gerberding, the new director of the Centers for Disease Control (CDC) ,recently told reporters, "We´re not in crisis mode. "
When West Nile hit New York City in 1999, the CDC realized it was a victim of its own suc- cess. Because health officials had conquered most mosquito-borne diseases decades ago, many states abolished their mosquito-control programs. The Feds rushed in with funds--some $ 50 million since 1999, plus $ 31 million more this year alone--to train insect researchers, set up state testing labs and kill off the annoying insects. The CDC established a new computer monitoring
system and held strategy sessions with state officials.
Some epidemiologists question the focus--and the millions--lavished on a virus that´s killed fewer than 20. "There´s an epidemic in gun violence that´s taking more lives than West Nile virus," says Dr. William Steinmann, director of the Tulance Center for Clinical Effectiveness and Prevention.
But the Feds say their efforts have kept West Nile from doing far more damage. "We´re basically building the infrastructure to deal with this over the next 50 years, "says Dr. Lyle Peterson, a CDC ep- idemiologist. "This is here to stay. "
So far, there are no remedies for West Nile. Officials eventually expect the virus to settle into a quiet pattern of mild infections with occasional outbreaks. To do battle at home, the CDC recommends eliminating standing water and using insect spray with DEET--simple precautions, but the best defense against an invader that shows no signs of going away.
In California scientists use chicken to