Emerging infectious diseases have attracted a great deal of attention over the past few years. Researchers and medical personnel have felt confident in their abilities to combat the majority of infectious diseases through medical breakthroughs, such as the creation of new vaccines, novel treatment regimes, and control and elimination of disease vectors. The public's belief that we had eradicated most infectious diseases has been shattered with the return of old diseases more virulent than ever, due to antibiotic resistance (e.g. tuberculosis). We are also seeing new diseases entering the human population; take, for instance, the worldwide AIDS epidemic that started in the 1980s. These new and emerging infectious diseases are appearing due to human activities and environmental factors. Humans are now able to travel from continent to continent in less that 24 hours, and thousands of pounds of raw goods (and manufactured ones) are imported and exported daily between countries. It is no wonder that disease endemic in human populations in one region could appear suddenly in another region. In addition, disease vectors, such as mosquitos and other insects, are able to travel as stowaways on human and freight transport, and can survive long distance trips.

Therefore, it is no wonder that the West Nile virus, a disease endemic in Africa and Asia, made its first appearence in New York City in 1999. While we could perhaps not have predicted that the West Nile virus would have been one of the first exotic viruses to cross the Atlantic Ocean in recent years, it is not surprising that it did. But since health officials were unprepared for its arrival and dissemination, they quickly took whatever action they thought was appropriate to limit its adverse health impacts upon humans, wildlife (mostly birds), and other animals (i.e. horses). Unfortunately, the activites chosen for the elimination of the contributing disease vector, mainly the mosquito species Culex pipien pipiens and Culex pipiens form molestus, have adverse health effects of their own. Government authorities decide upon countywide blanket aerial insecticide spraying and targeted larviciding of mosquito breeding sites. Pesticide exposure can result in illness or death, and steps must be taken to reduce such exposure so that the risks associated with pesticide spraying and larviciding do not outweigh the benefits of eliminating or vastly reducing exposure to the West Nile virus-infected mosquitos.

Since introduction of the West Nile virus to the United States occured only in the late summer and early fall of 1999, it would be an informative and useful contribution to the research community and general public to illustrate the characteristics of the West Nile virus and how it affects humans and other animals, how the virus could possibly become endemic in the United States, what pesticides were used in the New York City area to eliminate the primary West Nile vector (Cx. pipiens), what management strategies were used to respond to the West Nile virus outbreak, and the risks associated with contracting the virus and being exposed to pesticides.

Lastly, some recommendations are given for how local, state and federal government officials should continue to respond to the West Nile virus, should it become endemic in the United States, as well as how they should react to other new and emerging infectious diseases that may become introduced here in the future.