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As West Nile virus creeps towardCalifornia, an unlikely warrior could provide the first line of defense: the chicken. The familiar fowl make irresistible targetsfor mosquitoes. Unlike crows, chickens don't get sick from West Nile. But they do produce telltale antibodies to thevirus. So in test coops scattered acrossthe state, more than 2000" sentinel chickens" submit to frequentblood tests. When antibodies do turn up, California health officials will knowthat the inevitable has occurred: the West Nile epidemic will have swept thecountry.
Lastweek alone, more than 100 new human cases of West Nile were reported. The virus was detected as far west as Colorado andWyoming, 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-Juneinstead of August--and claimed younger victims; the average age dropped from 65to 54. Federal health officials arestill trying to figure out why, but say they may be finding more West Nileprecisely because they're on the lookout for it. As Dr. Julie Gerberding, the new director of theCenters for Disease Control ( CDC), recently told reporters ," We're notin crisis mode. "
WhenWest Nile hit New York City in 1999,the CDC realized it was a victim of its ownsuccess. Because health officials hadconquered most mosquito-borne diseases decades ago, many states
abolished their mosquito-control programs. The Feds rushed in with funds--some $ 50million since 1999, plus $31 million more this year alone--to train insectresearchers, set up state testing labs and kill off the annoying insects. The CDC established a new computer monitoringsystem and held strategy sessions with state officials.
Someepidemiologists question the focus--and the millions--lavished on a virusthat's killed fewer than 20. "There's an epidemic in gun violencethat's taking more lives than West Nile virus," says Dr. William Steinmann, director of the TulaneCenter for Clinical Effectiveness and Prevention. But the Feds say theirefforts have kept West Nile from doing far more damage. "We're basically building theinfrastructure to deal with this over the next 50 years, "says Dr. Lyle Peterson, a CDC epidemiologist. "This is here to stay. "
Sofar, there are no remedies for West Nile. Officials eventually expect the virus tosettle into a quiet pattern of mild infections withoccasional outbreaks. To do battle athome, the CDC recommends eliminating standing water and using insect spray withDEET--simple precautions, but the best defense against an invader that shows nosigns of going away.
In California scientists use chicken to A．sweep away the West Nile epidemic.
B．produce antibodies to West Nile virus.
C．fight against the spread of West Nile virus.
D．monitor the presence of the West Nile virus.
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