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Biology 103
2000 First Web Report
On Serendip


Sarah Naimzadeh

During the summer of 1999, several birds infected with the West Nile virus were found in all five boroughs of New York City, as well as Nassau and Suffolk counties on Long Island. West Nile virus, also known as Dengue Fever, is a viral illness with symptoms such as fever, rash, muscle aches, dehydration and headache. (1). The West Nile Virus, previously unheard of in the Western Hemisphere, occupied much of the news again this summer when more infected birds were found. The virus is particularly frightening due to its methods of transmission. Mosquitoes that feed on the infected birds can easily transmit the disease to humans; this raises many fears especially during the summer months when mosquito bites are a common occurrence. Also, according to the official website of the Center for Disease Control, there is no explicit treatment nor is there a vaccination. (2). While this disease is very serious, even fatal, especially for the elderly and children, only one person, an 82-year-old man with other ailments, died from the disease in 2000. (3). As a Long Island native, I remember vividly the hotly debated topic of the usefulness and safety of the sprayings that were implemented to control the virus. Many wanted the sprayings regardless, perhaps to feel as though they were being protected while others adamantly opposed the sprayings because of the lack of information of the disease as well as the low rate of human infection.

For the most part, sprayings were not questioned or protested during the summer months of 1999, possibly because there was a much higher rate of human infection. (1). According to the website of the New York City Department of Health, "the city [was] hopeful that with an early and aggressive campaign against mosquitoes, the need for aerial spraying of pesticides will be reduced." (4). Citizens of the New York Metro area were assured that there would be very public notice when the sprayings were to occur. The only area to resist the sprayings was Nassau County, the group of towns nestled between Queens and Suffolk County. The county executive, Thomas Gullota, opted not to spray Nassau at the first sign of the virus, a decision that prompted much controversy. "Nassau has avoided spraying because no infected mosquitoes have been found in the county." (5). John Wagner Shirley, in a letter to Newsday wrote, "the panic over the West Nile virus last year is forgivable - nobody knew what we were dealing with. Now we know that most people experience either mild or no symptoms. We know, too, that it is far less deadly than the flu, which killed about 176 Long Islanders last year while West Nile virus killed one." (6). This opinion is countered by the letter of Valerie Kovel, who wrote, "my family lives very close to the areas in Nassau where the dead birds have been found. It's not right that we must live in fear that we may be bitten by an insect that carries a potentially fatal disease and the elected officials who are supposed to serve and protect us have knowledge of the problem and do nothing but monitor dead birds and mosquitoes." (7).

Another issue with respect to spraying was the actual pesticide used. "Last year, helicopters spraying diluted Malathion and other pesticides flew in low over some communities during times they hadn't been expected under city-issued schedules, causing concern among residents." (8). According to medical researchers at the University of Florida and University of South Florida Medical Libraries, Malathion is a very dangerous chemical that even in low levels can cause death and birth defects. (9). This pesticide is under federal review for possible health risks. As an interesting example of contradictory reports, science never getting it right and the question of being "less wrong," the Environmental Protection Agency "released a preliminary report on Malathion...indicating the widely used pesticide may carry carcinogenic risks but that the risks are within acceptable limits." (10). The first obvious question is: what is an acceptable risk? One would hope that this would mean that the risk of cancer is less than the risk of what the Malathion seeks to destroy, in this case, the West Nile virus. I am not convinced that this is the case. Consider that out of all of the birds infected with the West Nile Virus, only one elderly man with other ailments died this summer and that New York City cites that less than 1% of mosquitoes in bird infected areas carry the virus. (8). As the article does not continue to define and clarify the term "acceptable risk," I am rather skeptical of the EPA report.

Among critics of the decision not to spray the county was City Mayor Rudy Giuliani, who thought that city residents would be at risk because of Nassau's decision not to spray the area. In New York City, Giuliani and the Department of Health (DOH) implemented a comprehensive plan of controlling the virus. The DOH planned to maintain surveillance, institute an education program and expand the use of larvae eating fish. In the event of human infection, the City was prepared to use adulticide, namely resmethrin, sumithrin, permethrin and Malathion. (11). Nassau's decision was made because only infected birds had been found not infected mosquitoes and no infected people, unlike New York City. One has to wonder why Nassau is seemingly unconcerned by the mosquitoes found in Queens and Suffolk counties. Since there are no physical barriers between the areas, why wouldn't Nassau take the initiative to control the mosquito population before they become infected and possibly infect humans? This opinion was common, as the editors of Newsday wrote, "Giuliani claims Nassau's inaction puts the city at risk. Nassau says its aggressive mosquito-control program may preclude the need for pesticides. Right now, the matter is a judgment call. But it's hard to believe that the county will not find infected mosquitoes before summer is out. Nassau should be prepared to break out the pesticides (as it did last year) on a moment's notice. Until then, keep your fingers crossed." (12).

So the question becomes, what is Nassau County doing to control the West Nile virus? In a press release dated October 5, 2000, county executive Thomas Gullota announced that eight infected birds have just been found, bringing the total count to 69 birds, but only a few infected mosquitoes and no infected humans. (13). The website for the Nassau County Mosquito Control Program states that spraying continues to be a last resort and that due to the cool weather, Nassau may not need to worry about this possibility until next year. The Nassau County Departments of Public Works (DPW) and Health (NCDH) are working together to monitor mosquito populations as well as using larvicides. (14). County residents are urged to become an active part in controlling the disease by "removing standing water, keeping pools chlorinated, installing window and door screens and avoiding bug zappers." (15). Standing water, like in pool covers, tires and patio furniture provide an ideal space for mosquitoes to breed. All of the websites concerned with West Nile virus have also advocated the use of DEET free insect repellants when outdoors.

Despite all of the concern and the increase in both birds and mosquitoes infected with the disease in New York state and elsewhere, few humans contracted the illness and only one died. "In fact, the number of birds and other animals that became infected with the virus rose significantly and spread geographically this year compared with 1999. Yet the number of human beings who contracted the virus actually dropped." (16). Also, despite the critique from Giuliani, Nassau County has not had one human contract the West Nile virus. So what have we learned from this summer? New York City and Suffolk County used pesticides to control the virus and Nassau did not. All areas had a drop in human contraction, but couldn't this be attributed to greater awareness of the potential dangers of mosquito bites? " 'What all this tells us is that we don't know everything we need to know,' said Dr. Stephen M. Ostroff, the West Nile coordinator at the federal Centers for Disease Control and Prevention. 'Here we are with only 12 human cases identified, and yet you have to believe that given the intensity of the transmission, the risk was at least as high to humans as last year. I personally believe that our prevention activities have worked. But we don't have a ready explanation.'" (16). I am very interested to see how the summer of 2001 will differ from this past summer, as there are already reports of the virus in Boston, Philadelphia and Washington D.C. Hopefully these areas will help us to understand a little more about the virus and the most effective means of prevention.

WWW Sources

1)WebMD - Dengue Fever, Definition, Symptoms and Treatment of West Nile Virus

2)Questions and Answers About West Nile Virus - CDC Division of Vector-Borne Infectious Diseases, Q&A from the CDC

3) - Health - West Nile virus claims first death this year - September 25, 2000, CNN article about first West Nile Death

4)New York City Department of Health - DOH West Nile Virus - General Information on West Nile Virus, FAQ from NYC DOH

5) - Wednesday - Rudy : No Spray, Nassau? Says city put at risk by county's decision not to use incesticide, Giuliani wants Nassau to use similar spraying schedule

6) - Tuesday - LETTERS It's Wise to be Wary of Spraying Pesticides, Letter to the Editors of Newsday

7) Friday - Letters, Another Letter to the Editors of Newsday

8) - Friday - City Nixes , NYC decides not to use Malathion

9)Malathion Health Research , Information on the potentially dangerous chemical

10) - EPA says Malathion carries risk but it is within acceptable limits, CNN Article about Malathion

11)New York City Department of Health - DOH West Nile Virus/ Comprehensive Anthropod-born Disease Surveillance and Control Plan 2000, See Mosquito Control

12) - Friday - EDITORIAL - Use Common Sense in Spraying for West Nile Virus, Editor calls for preparation

13)Nassau County Press Release, More birds found in Nassau

14)Nassau County Mosquito Control Program,What Nassau is doing to prevent/counter West Nile virus

15)Nassau County Mosquite Control Program, What you can do to prevent West Nile virus

16)West Nile Virus Data Cheers, and Puzzles, Health Officials, NY Times article on Surprising Summer