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Surveillance by the North Shore Mosquito Abatement District indicates that the risk of West Nile virus from infected mosquitoes has increased to moderate. T

he number of positive batches of mosquitoes tested in its lab through Aug. 13 increased from the previous week, pushing the vector Index to 2.68. A vector index greater than 1.0 is associated with increased likelihood of human infections.

WNV positive batches of mosquitoes have been found in NSMAD traps located in every community served this season. In response to the increase in WNV activity, the NSMAD will be conducting adult mosquito control operations in portions of the District to augment our continued larval mosquito control.

The NSMAD recommends that residents take personal protection measures to minimize mosquito bites by using EPA registered insect repellents, wearing loose fitting clothing and avoiding peak mosquito feeding times during the hours around dawn and dusk. Residents are urged to examine their property and eliminate any items that can hold water, particularly smaller items that may be easily overlooked. If it can hold water, it can breed mosquitoes.

West Nile virus is transmitted to humans via the bite of an infected Culex pipiens mosquito. Most people infected with the virus show no symptoms. Mild cases may cause a slight fever or headache. More severe infections are marked by a rapid onset of a high fever with head and body aches, disorientation, tremors, convulsions and, in the most severe cases, paralysis or death. Symptoms typically occur within three to 14 days after the bite from an infected mosquito. Persons 50 years of age or older are at the highest risk for serious illness.