Health threat example of entwined world

This is normally the time of year when mosquito commissions wind down their spraying. It's getting close to the first frost, and there are fewer insects because of the shorter and cooler days.

But in the New York metro region, helicopters and trucks are still fogging neighborhoods with insecticides - and plan to continue until the pesky insects are dormant. The reason: a mosquito-borne encephalitis virus that public-health authorities say is responsible for at least five deaths and as many as 40 hospitalizations.

Although officials are still tracking the origin of the West Nile-like virus, they believe its appearance illustrates a downside to the global community: Because of worldwide travel, few areas of the world can remain isolated. Insects can hide in airplane compartments, be smuggled in with illicit wildlife, or even bite a traveler returning from overseas.

"Anyone can bring these things in from abroad," says Jerome Levine, chief of the infectious diseases division at Hackensack University Medical Center in New Jersey.

Despite the quick reaction by local authorities, officials are warning that it's possible the new strain of virus will be around in the spring - and in a larger part of the country. Researchers believe migratory birds, after getting bit by a mosquito, might spread the virus.

"The only thing we can do is work with public health to increase surveillance," says James Hughes, director of the National Center for Infectious Diseases, part of the Centers for Disease Control and Prevention in Atlanta.

That's exactly what's happening in Monmouth County in New Jersey, where the local mosquito commission is still trapping the insects in illuminated boxes. "We have no reason to think this thing can't spread to anyplace in the state of New Jersey," says Martin S. Chomsky, superintendent of the commission in Tinton Falls, N.J. Indeed, in the northern part of the state, labs are testing dead crows that appear to have been bitten by mosquitoes.

With the need for increased surveillance, the American Mosquito Control Association expects to ask Congress for additional funding for next year. "We are trying to get additional funding for research," says Mr. Chomsky.

Surveillance is an integral part of the new method, called "integrated pest management." Chomsky says the goal is to "determine the most effective way to treat mosquitoes and at what time and with what technology." For example, many environmental groups object to the use of the pesticide malathion, which was used in California to spray for the Mediterranean fruit fly in the mid-1990s. Today, it is still being used to spray for adult mosquitoes. Authorities recommend individuals remain indoors during spraying. But there are now less-toxic insecticides, including one made from chrysanthemums.

One of the goals this fall has been to spray stagnant ponds where the mosquito larvae are located. When New York officials surveyed parts of Queens, they found many swimming pools filled with green, scummy water.

"This breed of mosquito likes breeding in water that is relatively stagnant with a lot of organic matter," says Thomas Daniels, a biologist at Fordham University. "So you would find it in old buckets, or pools where people may not have filled them up because of the drought."

This fall the city launched helicopters in residential neighborhoods in Queens. However, residents said they had been complaining to the city all summer about the insects.

Unfortunately, this was a good year for mosquitoes. Chomsky says the storm sewers became breeding grounds for mosquitoes because there was not enough fresh flowing water. Then, hurricane Floyd dumped a large quantity of water on the region. This has created a new potential breeding ground.

Until the first frost of the year, authorities are advising individuals to take normal precautions against mosquitoes.

(c) Copyright 1999. The Christian Science Publishing Society