News Release

PO 360
Trenton, NJ 08625-0360
Christine Grant
For Release:
July 21, 2000
For Further Information Contact:
Rita Manno
Marilyn Riley
NJ Home Page DHSS Home Page

State Begins Active Surveillance for WNV in Humans
Total of Nine Crows in Bergen, Hudson and Middlesex Counties are Positive
Sentinel Chickens and Mosquitoes Virus-free

TRENTON - The Department of Health and Senior Services, in cooperation with local health officers in five Northern New Jersey counties, will begin active surveillance for potential cases of West Nile virus (WNV) in humans.

Beginning next week, health officers in Bergen, Essex, Hudson, Passaic and Union Counties will call each hospital in their respective jurisdictions on a weekly basis to identify potential WNV cases which may not have been detected or reported.

This new surveillance method is part of the State's WNV action plan announced in March and is one of the many activities supported by State and local funding and a $200,000 grant from the federal Centers for Disease Control and Prevention (CDC) for increased WNV surveillance and testing. Active surveillance supplements the current human disease surveillance system that asks doctors, hospitals and labs to report possible human cases of WNV to the Department of Health and Senior Services.

To date, no resident has received a WNV test in New Jersey although more than two dozen residents with conditions that did not meet established testing criteria have been prescreened for WNV infection by private laboratories using a test traditionally used to detect St. Louis Encephalitis (SLE). Since SLE and WNV are closely related viruses, a WNV case will react positively to a SLE test. All results have been negative and further testing for mosquito-borne viruses were not necessary.

In New Jersey, a team of experts from the departments of Health and Senior Services, Environmental Protection, and Agriculture; state and county mosquito control commissions and programs; local health departments and Rutgers University are conducting WNV monitoring and mosquito control.

To date, 237 crows and 3 pigeons have been submitted and accepted for testing to the New Jersey Department of Health and Senior Services' Public Health and Environmental Laboratory. Seven crows found in Bergen County and two crows found in Hudson and Middlesex counties have tested positive for the presence of the WNV. At least one crow sample has been submitted from all 21 New Jersey counties.

Also to date, 299 blood samples taken from sentinel chicken flocks placed in all 21 counties and 349 mosquito pools collected in every county, have all tested negative for WNV.

The West Nile virus, an arboviral disease, is transmitted through the bite of a mosquito that has picked up the virus by feeding on an infected bird. The virus is not directly transmitted from birds to humans or from person to person. WNV infection generally causes no symptoms or just mild, flu-like symptoms. However, the elderly are at higher risk of more severe disease.

The West Nile virus was first isolated and identified by the CDC in September 1999 in birds found dead in New York City and Westchester County. The virus was responsible for 62 human cases of encephalitis in New York State and seven deaths.

New Jersey residents have been advised to take precautions to reduce their risk of mosquito bites. This includes spraying insect repellent on their clothing and exposed skin in accordance with labeling directions and wearing long sleeved shirts and pants when outdoors. Residents can also curb outdoor activities at dawn, dusk and during the evening. Residents should also eliminate standing water on their own property that can serve as a breeding ground for mosquitoes.

For more information on West Nile virus, visit the State Department of Health and Senior Services' website at, the State Department of Environmental Protection's site at, or the CDC's site at

# # #

NJ Home Page DHSS Home Page