As we go to press, Nassau public officials are scrambling to monitor the extent of the West Nile-like virus outbreak, determine which areas to spray and communicate with the public. Mixed messages from Nassau County officials as to spraying schedules were causing school districts, today, to cancel outdoor events only to learn later that spraying in their respective areas had been cancelled. Nassau County Public Health Commissioner Gaffney said, "We're reserving judgment on what we are going to do next." Homeowners will be pre-notified by yellow fliers if and when spraying will occur near their property.

On Thursday, Sept. 23 after the news broke about a dead crow from Conn. that had been analyzed revealing the St. Louis encephalitis virus (SLV), a call came in to the Record from a local school teacher who had spotted six dead crows in July in Great Neck.To date, there have been 13 confirmed cases of dead crows reported in Great Neck.

On Friday, Sept. 24, the Record spoke first with Dr. Kevin McGowan, curator and senior research associate of Ornithology at Cornell who specializes in crow research. He confirmed that while birds may be infected with the SLV, and may be sick for a few days, it does not cause mortality. He added that during the summer, he had reports of dead crows from different regions in New York. Dr. McGowan thought that a different strain of an encephalitis virus might be at work.

In a call to Dr. John Smith, director of the John A. Mulrennan, Sr., Public Health Entomology Research and Education Center (PHEREC) which is affiliated with Florida A&M University, the Record learned more about sophisticated measures to monitor, understand and control mosquito populations. Florida spends $100 million per year in mosquito control and research. According to Dr. Smith, a medical entomologist, there are three essential components involved in keeping mosquitoes at bay. First, weather conditions play a large role in the behavior and breeding patterns of different species of mosquitoes. The time span from egg laying to adult hatching may vary up to a week or more depending on how warm it is. Mosquito activity in general slows down with cooler weather. Precipitation is taken into account as well since some species of mosquitoes hatch with an onslaught of water.

Second, in Florida mosquitoes are trapped but only to estimate population numbers and species present. Dr. Smith said, "Viruses die very quickly when the host is dead. Capturing mosquitoes for analysis is an inefficient and inadequate way of making accurate determinations." He stressed that the third and only reliable way to pick up on viral transmissions is to analyze the blood of live birds. For this reason, Florida uses flocks of "sentinel chickens" for this purpose, testing blood samples from the flock every two weeks.

On that same Friday, the Record, according to press protocol, phoned Cynthia Brown, Nassau County Health Department's public information director to apprise her of the above information and to stay abreast of any new developments in Nassau County.

On Friday afternoon, Sept. 24, the announcement was made that the State Department of Environmental Conservation's Pathology Office had discovered that dead birds were found to have a "West Nile-like" virus hitherto undocumented in the Western Hemisphere. In speaking with Ward Stone, DEC state pathologist on Saturday, Sept. 25 to report the dead crows from Great Neck, he confirmed that indeed his office was interested in information regarding dead birds and where they are dying. Mr. Stone's office is working feverishly to handle the lab work necessary to put the pieces of this medical puzzle together. Not an easy task given that he has one biologist, two technicians and one secretary to handle a more and more complicated encephalitis outbreak.

To wage a good fight against mosquitoes, one must understand the peculiarities of the critters. The first mosquito implicated when the St. Louis encephalitis virus hit the news is called Culex pipiens by the culicidologists (mosquito experts) better known to the public as the northern house mosquito. This mosquito breeds in permanent waters that are rich in organic wastes, such as storm sewer catch basins, clean and polluted ground pools, effluent from sewage treatment plants and the like. They lay their eggs in large clusters called "rafts" and these eggs go though a metamorphosis into larvae, pupa and finally adults in 8-12 days depending on the temperature. The adult females overwinter in a state similar to hibernation in protected areas even in cold climates.

The mosquito that is thought to carry the West Nile-like virus is the Aedes Vexans, one of the most widespread mosquitoes in the world. From a biological standpoint, they are considered highly successful and here's why: A wide range of habitats suits their needs. Aedes Vexans lay their eggs in moist soil in sites where water accumulates temporarily due to rain water, overflow or tidal flow, putting them in a separate category of mosquitoes. Their eggs can live up to 3 years, just waiting to emerge when water inundates them. The adults die with the cold weather, but the eggs do not. Further, these mosquitoes tend to congregate during the day in shady areas although they most often go on biting forays at dawn and dusk.

The anopheles mosquito, a vector suspect for West Nile-like virus, is also a permanent water breeding mosquito, similar to Culex pipiens.

According to the culicidologists, it is not just what is sprayed, but how and when that is important. Currently, Malathion is being sprayed by New York City and Westchester County. According to Dr. Smith, it is widely used because it is reliable under certain conditions and it is cheaper at $19 gallon than other pesticides used in the mosquito chronicles. However, it is "worthless" if sprayed when the temperatures are in the 40s, according to Dr. Smith.

In addition, studies being conducted at PHEREC indicate that newly developed spraying nozzles that spray a finer mist are not only more effective, but do less environmental damage to other living organisms than sprayers that release larger particles. Most pesticides commonly used, kill on direct contact with the mosquito, but with Malathion, it takes 24 hours for the mosquito to die. Even potent pesticides, according to a report from the Ohio State Extension Service are safer environmentally and more effective if applied with ultra-low volume (ULV) techniques. For every 50 percent decrease in the droplet diameter of a set volume of insecticide, the spray surface area is increased eightfold. It is important to know that newly hatched mosquitoes will be virus free at least until their first blood meal. If they bite infected birds, they may become disease vectors.

Although birds and mosquitoes appear to be the primary agents in the West Nile-like virus, there are reports in the scientific literature that other mammals may be affected. Horses are susceptible to infection with this virus and can develop encephalitis. Antibody to West Nile virus have been detected in cows and dogs, but infection caused mild or no clinical signs of disease, according to Dr. Amy Glaser, Cornell University, School of Veterinary Medicine. It is also important to understand that this virus is transmitted only by mosquitoes and that infected mammals do not transmit the virus to other mammals. she stressed that while there is good evidence that mammals, other than humans, are affected, when outbreaks like this occur, it may take several months before reliable information trickles in and many more months before sound conclusions can be reached. Prevention of exposure is the best way to avoid infection in any species. In this case, this means keeping animals indoors during hours when mosquitoes are active (dusk to dawn) and using insect repellents, similar to recommendations made for limiting exposure in people.

Scourge, the trade name for the insecticide being used on Long Island, has been verified by Dr. Smith and Martin Chomsky, regional director of the New Jersey Mosquito Commission as being highly effective. Dr. Smith added that it is more environmentally safe than Malathion albeit more expensive at $100 per gallon.

While the experts do not agree on all the intricacies of mosquito control, especially monitoring techniques, they do agree that it is vital to have an on-going, well-funded preventive program to combat mosquitoes to avoid outbreaks. Dr. Smith says, "In the long run, hit and run approaches don't work."

On the morning of Sept. 28, Cynthia Brown spokesperson for the Nassau County Health Department reported that Nassau County would be spraying Scourge, a derivative of chrysanthemum, by truck in Bayville, Manhasset, Garden City, Sands Point, Port Washington and Hempstead. But by Tuesday afternoon, the County Executive's office announced that only Bayville would be sprayed on Sept. 28.

If you see a dead bird (no road-kill, please), call 571-8707 immediately.