WNV is a mosquito-borne virus that is commonly found in Africa, West Asia and the Middle East. In recent years, it has been found in the United States. The onset of symptoms is three to 14 days after being bitten by an infected mosquito. Most people infected with the WNV experience few if any symptoms and recover completely after a few days. Mild symptoms include a fever, headache, body aches, swollen lymph glands and occasionally a skin rash on the trunk of the body. Although rare, some people experience severe infection (West Nile encephalitis or meningitis), with symptoms including headache, high fever, neck stiffness, stupor, disorientation, coma, tremors, convulsions, muscle weakness and paralysis.

Mosquitoes become infected with the WNV when they feed on infected birds and can then transmit the virus to humans and animals while biting to take blood. The WNV is NOT transmitted from person-to-person. Other possible transmission routes of the virus are being studied. In areas where the virus is circulating, very few mosquitoes are infected. Even if the mosquito is infected, there is a very low chance that people who get bitten and become infected will get severely ill. The chances you will become severely ill from one mosquito bite are extremely small.

JCHD has a trapping and testing program that operates May – October. JCHD staff also work with all municipalities and townships to be trained to apply larvicide in areas that need to be treated.