West Nile virus cases on Long Island approached near records due to warm fall

A Huntington resident hospitalized last month due to West Nile virus, the 21st human case in Suffolk and at least the 41st on Long Island this year, is recovering from the illness at home, Suffolk health officials announced Tuesday.

Since the first case was confirmed in an Islip man on Aug. 7, Suffolk County Health Commissioner Dr. Gregson Pigott has reported 21 cases of West Nile virus in the county this year, according to a press release Tuesday. This year marks the second-highest number of human cases of West Nile virus in a single year since Suffolk County began tracking cases in 2000. A total of 235 mosquitoes tested positive for the virus in Suffolk, the second highest ever in a single year according to county data.

The year 2010 holds the Suffolk County records for the most human cases in a single year — 25 — the most deaths from West Nile in a single year — three and the most mosquitoes which tested positive for the virus in a single year — 295.

This year, 20 Nassau County residents have been infected with West Nile virus, Nassau County Health Department spokesperson Alyssa Zohrabian confirmed via email Tuesday. This marks the second highest number of human cases in Nassau, according to county data since 2014. The highest number of cases was 24, recorded in 2022.

The Huntington case marks the most recent since health officials announced a Smithtown resident was infected on Oct. 11. Newsday previously reported that most human cases are detected in August and September. Fall temperatures and the lack of precipitation over the past three months may have been a factor in the virus lingering this late in the year, according to Dr. Pigott. 

"The warmer than normal fall with little rainfall might account for West Nile virus activity in November," Dr. Pigott said in a statement. "Now is a good time to prepare for next year. Many species of mosquitoes overwinter as eggs on the sides of water-filled containers, so we recommend scrubbing bird baths and buckets to prevent eggs from hatching in the spring when mosquitoes will start biting again."

The Huntington resident infected last month and two other individuals infected earlier this year were the only people under 50 who contracted the illness in Suffolk this year, according to the release. Health officials said those over 50, as well as those with chronic illnesses or compromised immune systems, are at higher risk for severe West Nile infection.

Six of these 21 infected individuals live in the Town of Islip; nine reside in the Town of Brookhaven; three hail from the Town of Smithtown; two live in the Town of Huntington; and one resides in the Town of Babylon, according to health officials.

Mosquitoes infected with West Nile virus can transmit the disease to humans via bite, health officials said. Symptoms typically occur within two weeks of transmission, and can range from fever, head and body aches and skin rash to convulsions, muscle weakness, vision loss and paralysis, according to the release. The virus can prove fatal.

Anyone who experiences symptoms of West Nile are advised to visit their health care providers, Dr. Pigott said. Suffolk residents can report mosquito concerns or stagnant pools of water to the Department of Public Works’ Vector/ Mosquito Control Division by calling 631-852-4270.