Mosquito tests positive for West Nile virus showing up earlier, in greater numbers in Suffolk

The West Nile virus has been detected in a new batch of 40 mosquito samples collected earlier this month, Suffolk health officials announced Tuesday, continuing a trend of the virus showing up early and in greater numbers than prior years.

In addition to the blood-sucking insects, two birds recently sampled — a blue jay in Selden and a mallard in Smithtown — also tested positive for the virus.

Seventy-two mosquito samples tested positive for West Nile so far this year in Suffolk County, officials said. Grace Kelly-McGovern, a spokesperson for the Suffolk County Department of Health Services, confirmed this is far greater than numbers reported at this point in the season in recent years.

On July 28, 2023, she said the county reported a total of seven cases since first detecting them earlier in the month. By July 29, 2022, she said a total of 12 mosquitoes tested positive for West Nile virus for the season.

Suffolk County recorded 99 positive mosquito samples and five human cases of West Nile virus throughout the entire 2023 season. In 2022, 96 mosquitoes and 11 humans tested positive for the virus. Kelly-McGovern said several birds also test positive annually, typically robins, blue jays, hawks and other birds of prey.

Earlier this month, Newsday reported a batch of 16 mosquito samples tested positive for West Nile virus. At that time, Dr. Scott Campbell, director of the county's Arthropod Borne Disease Lab in Yaphank, said public health researchers have often detected West Nile in as many as 16 mosquitoes in a single batch, but typically later in the season.

“We’re ahead of our normal progression,” he said before adding that “in theory,” this advanced timeline could mean more positive cases than usual as the year progresses.

In a news release dated Tuesday, Suffolk Health Commissioner Gregson Pigott said "While there is no cause for alarm, we advise residents to cooperate with us in our efforts to reduce exposure to West Nile virus and other mosquito-borne diseases."

The Nassau County Department of Health has reported that 16 mosquitoes tested positive for West Nile virus so far this year, according to a department spokesperson. They were collected between July 10 and July 19 in Hicksville, Plainview, Plandome Manor, Searingtown, Lakeview, Massapequa, Massapequa Park, East Meadow, Oyster Bay Cove, Garden City, Mineola, East Hills and Old Westbury.

Anthony Falco, Nassau County Vector Control supervisor, said said his team has been patrolling South Shore salt marshes for mosquito larvae since May 1. According to public notices issued, Nassau's vector control division sprayed pesticides via helicopter to combat mosquito larvae on May 16, May 29 and June 20. Newsday previously reported that Suffolk County Vector Control has similarly applied pesticides via helicopter at Suffolk wetlands four times between June 11 and July 23.

The federal Centers for Disease Control and Prevention report 72 cases of West Nile virus in humans across 21 states so far this year. There have been no reported human cases in New York State, according to CDC data as of Tuesday.

Suffolk's most recent batch of mosquito samples were taken July 16-17 and involved mosquitoes testing positive in: Melville (6); Northport, Dix Hills and Setauket (3 each); Aquebogue, Manorville, Holtsville, Brentwood and Port Jefferson Station (2 each); and, Cold Spring Harbor, Greenlawn, West Babylon, Lindenhurst, West Islip, Mount Sinai, Smithtown, Commack, Nesconset, Bay Shore, Holbrook, Islip, Farmingville and North Patchogue, which each had 1. A July 10 test in Manorville also had 1 positive sample.

West Nile was first detected in mosquitoes and birds in Suffolk in 1999, officials said. The virus is transferred to humans through mosquito bites and has been discovered each year since, officials said.

Officials said most people infected with West Nile with exhibit mild or no symptoms, though some can develop severe symptoms which include high fever, headache, neck stiffness, stupor, disorientation, tremors, convulsions, muscle weakness, vision loss, paralysis, numbness and even coma.

Officials recommend residents, especially  those age 50 and older and those with compromised immune systems, limit outdoor activities between dusk and dawn and wear shoes, socks, long pants and long-sleeved shirts when mosquitoes are active. The use of repellent also is advised.

Officials also warn that standing water can be prime breeding grounds for mosquitoes and recommends weekly cleaning — and emptying — or any containers, vases, pet water bowls, flowerpots, old tires, buckets, birdbaths, trash cans and other outdoor items to clear your premises of mosquito eggs.

Dead birds also may indicate the presence of West Nile and officials ask you report any finds in Suffolk to the Bureau of Public Health Protection at 631-852-5999 between 9 a.m. and 4 p.m. To report mosquito problems or stagnant pools of water at locations in Suffolk, contact the Department of Public Works’ Vector Control Division at 631-852-4270.