City and state officials are bracing themselves for a new West Nile invasion.
“We are preparing for any possibility,” said Sandra Mullin, spokeswoman for the city Health Department.
“We have no idea what will happen this year. The only thing we know is that West Nile will return.”
Mosquito control will begin in the city this month and focus on eliminating possible breeding grounds by using larvicides, which are sprayed into sewers and other risky areas like swamps.
One targeted spot is East 91st and 92nd streets, which last summer had sewers filled with breeding mosquitoes.
Health officials, however, have no immediate plans for the overhead spraying they did last year and are hoping not to have to.
Officials are particularly concerned because there is no way to predict with certainty how bad the virus will be this season.
“In countries such as Israel, where West Nile has been around for a long period of time, outbreaks of disease tend to be sporadic,” explained Lyle Petersen of the federal Centers for Disease Control and Prevention.
“That makes it hard to predict what will happen from year to year in the U.S.”
The only thing scientists are sure of is that the West Nile virus will continue to spread geographically. Last year it traveled from the New York City area to as far north as Canada and as far south as North Carolina.
Although the city Health Department has found few mosquitoes this year because of the unusually cold winter, health officials aren’t resting easy.
“We had a lot of snow this winter, so if you end up with melting snow and then a rainy spring, there will be many pools of stagnant water where mosquitoes can breed,” said Kristine Smith, spokeswoman for the state Health Department.
A dry summer could also spell trouble – culex mosquitoes, the skeeters that chiefly transmit West Nile, thrive on drought, according to Durland Fish, associate professor of epidemiology at Yale University School of Medicine.
But even as health officials beef up their efforts to extinguish the mosquito-borne disease, they say they will decrease their use of pesticides. “Last year, we were very aggressive. If one dead bird with West Nile was found, the CDC recommended spraying a 2-mile area,” said Smith.
This year, the state Health Department does not recommend spraying an area unless there are emergency circumstances such as an infected human or a rash of infected birds.
“These guidelines better balance the threat of the virus against the risk of pesticide exposure,” explained Smith.
The city’s Health Department has yet to unveil its spraying guidelines, although it’s expected to follow the state’s lead.
Last year, despite spraying, about five out of every 1,000 mosquitoes were infected – which means thousands of mosquitoes with the virus were swarming around the city.
Although there were only 21 human cases of West Nile reported to the CDC last year, federal officials say the numbers of people actually infected are higher.
An estimated 1,574 Staten Island residents – about one in every 200 – were unknowingly infected with the virus, according to a survey conducted last October by the city Health Department.
Estimated $$ spent on West Nile nationally last year: $50 million
–Between May 1, 2000, and January 15, 2001, the West Nile virus has been detected in:
20 humans
59 horses
4,323 birds
6 other mammals (two bats, one chipmunk, one skunk, one squirrel, and one rabbit) 481 mosquito pools
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Here’s who tested positive for West Nile Virus in New York City in 2000:
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Staten Island:
Humans: 10 (recovering)
Birds: 61
Mosquito Pools: 131
Horses: 8 (6 were asymptomatic)
Other mammals: 1 squirrel, 1 rabbit
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Manhattan:
Humans: 1 (recovering)
Birds: 36
Mosquito Pools: 17
Other mammals: 1 raccoon
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Queens
Humans: 1 (recovering)
Birds: 29
Mosquito Pools: 5
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Bronx
Birds: 13
Mosquito Pools: 6
Horses: 2
Other mammals: 1 squirrel
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Brooklyn
Humans: 2 (1 deceased, 1 in rehabilitation)
Birds: 38
Mosquito Pools: 11
Other mammals: 1 squirrel
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Where West Nile spread in 2000:
STATE / HUMANS / BIRDS
Conn. / 11 / 117
Delaware / 0 / 1
D.C. / 0 / 5
Maryland / 0 / 50
Mass. / 0 / 448
N.H. / 0 / 7
N.J. / 5 / 1,289
N.Y. / 14 / 1,278
N.C. / 0 / 1
Pa. / 0 / 32
R.I. / 0 / 87
Vermont / 0 / 1
Virginia / 0 / 7
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Sources: Centers For Disease Control And Prevention, NYC Dept. of Health, U. S. Dept. of Agriculture