Reduce exposure to mosquitoes — record level of mosquito activity continues to be observed
Nine cases of West Nile virus disease have been identified in humans so far this season
The Health Department today reminded all New Yorkers to continue to protect themselves against mosquitoes and West Nile virus. Mosquitoes are active in New York City from April through October. So far this season, 9 cases of West Nile virus disease have been identified in New Yorkers, 4 from the Bronx, 2 from Queens, 1 each from Brooklyn, Manhattan, and Staten Island. The amount of West Nile virus activity varies every year. To date, a record-breaking 1,039 West Nile virus-positive mosquito pools—mosquitoes gathered from the same trap site and tested together for the virus—have been identified. On average, the Health Department identifies 309 positive mosquito pools each season. Previously, 2018 was noted as a record with 1,024 positive pools for the entire mosquito season. This year’s warm, wet weather may be contributing to these higher counts.
“While the end of summer is around the corner, we want all New Yorkers to be aware that mosquitoes are still active and we’ve seen record numbers of activity this season,” said Health Commissioner Dr. Dave A. Chokshi. “When outdoors, make sure you wear insect repellent and remove standing water from your property. If you observe standing water not on your property, please report it to 311.”
The West Nile virus was first detected in New York City 22 years ago. Since 1999, the number of human cases has ranged from 3 to 47 annually. Of the 359 West Nile virus neuroinvasive disease cases reported through last year, 47 (13%) died due to their infection. New York City has over 40 species of mosquitoes, but West Nile virus is transmitted primarily by several Culex species, including Culex salinarius and Culex pipiens.
The Health Department has successfully helped control mosquito-borne diseases since the West Nile virus was first detected in NYC. The Department uses a comprehensive, integrated pest management approach to prevent and control mosquitoes which can transmit West Nile virus. This includes reducing standing water where mosquitoes can lay their eggs, applying larvicide in bodies of standing water that cannot be drained such as catch basins and marshland, and spraying pesticides to target adult mosquitoes where persistent West Nile virus activity is detected. The Agency’s data-driven approach relies on mosquito trapping and testing to determine where in the city to apply larvicides or other pesticides