New West Nile surge hits NYC as 2026 cases outpace all of 2025
New York City has logged 30 West Nile virus cases this year (as of Sept. 18, 2026), already exceeding the 2025 total of 18; Brooklyn leads with 11 cases, followed by Queens and Staten Island (7 each), the Bronx (3) and Manhattan (2). Of the cases, 24 are the neuroinvasive form (encephalitis, meningitis or paralysis). Health officials attribute the surge to warmer temperatures and humidity that boost mosquito populations and viral replication, with many infections mild or asymptomatic and thus underreported; 1,700+ positive mosquito pools this year indicate a larger outbreak, and the city continues mosquito-control efforts. West Nile is the only mosquito-borne disease in NYC.