New York Lyme disease cases jump 16% as East End deer population surges

Summer is ending, but tick season is not. 

Health officials warned Tuesday that autumn brings another peak in tick activity — as Southold wrestles with an exploding deer herd and Lyme disease cases surge statewide.

Preliminary state figures show approximately 25,000 Lyme cases in 2025, nearly 16% more than the 21,632 recorded in 2024. About 3,000 of last year’s cases were in New York City, leaving roughly 22,000 elsewhere in the state.

State Health Commissioner Dr. James McDonald disclosed the troubling increase during a visit to Stony Brook Southampton Hospital’s Regional Tick-Borne Disease Resource Center and Clinic in Hampton Bays.

“I think it’s safe to say the ticks are winning,” Dr. McDonald said. “We are in a time where we have to think differently about ticks. They’re no longer just a nuisance, but ticks really are a rising threat.”

His assessment echoed an exchange during Southold Supervisor Al Krupski’s Aug. 13 State of the Town address. When a resident said the town was “losing the war” against its growing deer herd and the spread of tick-borne illnesses, Mr. Krupski agreed.

“We are, there’s no question,” he said.

A day earlier, Southold’s Deer Management Task Force confronted the local side of that threat, considering stronger measures against a herd officials say remains far above sustainable levels.

The preliminary discussion included expanded crossbow access, greater flexibility in handling harvested deer and preparations for the coming hunting season. The state Department of Environmental Conservation’s Deer Management Assistance Program begins Sept. 13 in Southold.

Dr. John Rasweiler, a wildlife scientist who has served on Southold’s deer management committee since 2009 and Suffolk County’s Tick Control Advisory Committee since 2014, called the town’s earlier deer-management pilot ineffective.

“We didn’t get anywhere near what we needed,” Supervisor Al Krupski said of the 2023 pilot program.

Mr. Krupski said the task force also discussed expanding meat-donation efforts and the possibility of teaching residents how to process harvested deer.

“They did talk about different programs, like meat donation,” Mr. Krupski said. “It would be good if there was a butchering class for people because people could take the free deer. There’s a lot of meat and with the price of meat, it would be good if people could butcher it themselves and have a lot of good, high-quality protein.”

Town officials are also considering whether professional sharpshooters should play a larger role because recreational hunting has not kept pace with the herd’s growth.

“However, when populations are this high, it’s important to note that recreational hunting cannot control it alone,” said Councilwoman Alexa Suess, the task force liaison. “Hunting is a time-intensive and physically demanding activity, and even with the deer management strategies that we have in place, populations continue to grow.”

Estimates place Southold’s herd at roughly 65 to 75 deer per square mile. Dr. Rasweiler has said an environmentally sustainable level would be closer to 10 to 15 per square mile.

Deer are particularly important to the life cycle of blacklegged ticks, which can transmit Lyme disease. Adult females commonly feed and mate on deer before dropping off and laying eggs, allowing a large herd to support large numbers of ticks.

The statewide numbers mask an even sharper divide within Suffolk County.

“We have done some analysis, and the East End appears to be a higher risk compared to the West End,” said Dr. Scott Campbell, chief of the Arthropod-borne Disease Laboratory at the Suffolk County Department of Health Services.

The statewide increase follows an unusually active start to this year’s tick season. In April, tick bites accounted for 183 of every 100,000 emergency-room visits in the Northeast, up from 131 during the same period last year and the highest level for that point in the year in nearly a decade, according to the Centers for Disease Control and Prevention.

Officials on Tuesday identified blacklegged ticks, lone star ticks and American dog ticks as the three primary concerns in Suffolk County. They cautioned that the danger does not disappear when summer ends.

Suffolk County recorded 3,152 Lyme disease cases in 2024, the latest finalized county figure available, after 3,299 in 2023 and 2,668 in 2022. New York changed its Lyme disease reporting methodology in 2022, making direct comparisons with earlier years difficult. County figures for 2025 were not immediately available.

Dr. Campbell said adult blacklegged ticks become particularly active in October and can remain active throughout the winter whenever temperatures rise above 40 degrees.

“There’s no friendly tick, and since there’s no friendly tick, I’m concerned about preventing us from having any tick bites,” Dr. McDonald said.

Lyme disease remains the most commonly reported tick-borne illness in New York, but the East End has confronted other emerging threats. Lone star tick bites can trigger alpha-gal syndrome, an allergy to red meat and other mammal products. 

Suffolk County has reported four cases of tularemia this year, including a 9-year-old Riverhead boy infected by a tick and a Riverhead woman who contracted the illness after her infected cat bit her. The rare bacterial disease, commonly called rabbit fever, can spread through tick and deer-fly bites or contact with infected animals.

While government agencies continue surveillance and deer-management efforts, state health officials said personal protection remains the most immediate defense.

They recommend wearing long pants and long sleeves in wooded or grassy areas, using an EPA-registered tick repellent and performing full-body checks after spending time outdoors. Children and pets should also be checked, and clothing can be placed in a dryer on high heat for 10 minutes to kill ticks.

Dr. McDonald stressed that the rising threat should not keep people indoors, but it should change how they prepare before venturing outside.

“Although the ticks are winning, we live here, too,” he said. “And we aren’t giving up.”