Discovered in Uganda in 1937, West Nile Virus accounted for sporadic outbreaks of illness in Africa, Asia, Europe, and the Middle East. It was first seen in the United States in the late summer of 1999 when it sickened dozens of New York residents and claimed several lives. Since 1999, it has resurfaced each spring and is responsible for 83 human cases resulting in nine deaths between 1999 and 2000. By the end of the year 2001, the virus had been found in 1,078 crows and 357 mosquito pools. At least nine New Jersey residents had contracted the virus.

West Nile Virus is a mosquito-borne illness transmitted through the bite of an infected mosquito. Adult female mosquitoes become infected when they feed on infected birds and then transmit the disease by biting humans and other animals. West Nile Virus is not transmitted from person to person. The control of mosquito breeding continues to be an essential element in the prevention of human disease.

The incubation period in humans is 3 to 15 days, but not all humans infected with the disease become ill. Most infections are mild and symptoms may include fever, headache, body aches, skin rash and swollen lymph glands. Most people recover from the disease. When more severe symptoms occur, they can range from fever, rash and headache to meningitis, encephalitis, coma and death. The most serious illness tends to occur in the elderly and those with weak immune systems. There is no specific treatment or vaccine, but most people recover completely within two weeks.

Bergen County has taken a pro-active approach to the surveillance and control of West Nile Virus. For example:

• In 2000, a West Nile Virus Task Force was convened by the Bergen County Executive and includes representation from the Bergen County Division of Mosquito Control, the Office of Emergency Management, the Bergen County Department of Health Services, the Bergen County Animal Shelter, Bergen County Parks Department, local health officers, veterinarians, Rutgers University Extension Service and Hackensack University Medical Center. The purpose of the task force is to develop coordinated plans for prevention of the West Nile virus, to share information, and communicate with various community groups.
  
  
• Bergen County Mosquito Control Division works year-round on stream clearance, adjustment and repair of dykes, reduction of standing water, equipment maintenance and updating maps of mosquito breeding sites. Among many other duties, they perform active surveillance of larvae in early spring and stock ponds in Bergen County with mosquito-eating fish.
  
  
• The Bergen County Office of Emergency Management provides updates to local government, health and police departments as well as conducting periodic briefings on West Nile Virus for emergency management coordinators.
  
  
• Bergen County Department of Health Services coordinates bird submissions, maps and communicated testing results throughout the county. Professionals at the department use the information gathered to help prevent human disease.