The number of mosquito pools testing positive for West Nile virus in New York City has nearly doubled compared to the same period last year, according to city health officials. As of July 25, 612 out of over 2,000 sampled mosquito pools across the five boroughs have tested positive for the virus.
In response, the NYC Health Department has increased mosquito surveillance, deploying additional traps and expanding mosquito control efforts. Four targeted operations have been conducted since July, which officials say reduced adult mosquito populations by approximately 70% and decreased West Nile-infested mosquito pools by more than 85%.
"The detection of West Nile virus in mosquitoes demonstrates that New York City’s mosquito surveillance system is working exactly as intended," NYC Health Commissioner Dr. Alister F. Martin said in a press release. "Now is the time for every New Yorker, especially older adults and people with weakened immune systems, to take simple precautions to prevent mosquito bites."
While all five boroughs have detected positive mosquito pools, Staten Island and Queens have shown higher concentrations. Despite the rise in positive mosquito samples, no human cases of West Nile virus have been reported in New York City this season. Typically, cases in humans tend to increase between mid-July and early fall.
The West Nile virus, the only mosquito-borne disease known to spread to humans in New York City, has been present in the city for over 25 years. Most people infected do not develop symptoms, but about 20% may experience mild illness including fever, headache, body aches, nausea, and vomiting. In rare, severe cases, the virus can lead to serious neurological conditions such as encephalitis or meningitis.
Health officials recommend several precautions to protect against mosquito bites. These include limiting outdoor activities during dawn and dusk when mosquitoes are most active, using an EPA-registered insect repellent, and wearing long-sleeved shirts and pants when in areas with high mosquito populations.
