Tick population spikes early in Connecticut after snowy winter

Two ticks col­lect­ed byJamie L. Can­toni, an agri­cul­tur­al research tech­ni­cian for the New Haven-based Con­necti­cut Agri­cul­tur­al Exper­i­ment Sta­tion, in the UConn for­est. The larg­er, more col­or­ful tick on the left is a female, and the small­er one on the right is a male. Pho­to by Alli­son Gol­len­berg

By Alli­son Gol­len­berg | UConn Jour­nal­ism
June 8, 2026

The num­ber of ticks infect­ed with Lyme dis­ease is spik­ing ear­ly this sea­son in Con­necti­cut, data from the Con­necti­cut Agri­cul­tur­al Exper­i­ment Sta­tion shows, as envi­ron­men­tal con­di­tions give ticks a chance to thrive.

Dr. Goudarz Molaei, an ento­mol­o­gist and research sci­en­tist at the Con­necti­cut Agri­cul­tur­al Exper­i­ment Station’s tick test­ing lab in New Haven, said the aver­age rate for adult ticks infect­ed with the Lyme dis­ease pathogen test­ed at the sta­tion usu­al­ly hov­ers around 32%. But as of May 19, he said the infec­tion rate had already reached 38.5%.

“This time of year is not our peak sea­son,” Molaei said. “But we’re receiv­ing num­bers that are sim­i­lar to peak tick activ­i­ty.”

The sta­tion pro­vides free test­ing on ticks col­lect­ed by res­i­dents across the state, gath­er­ing data that’s help­ful for track­ing tick activ­i­ty and diag­nos­ing dis­ease in humans. In late March and ear­ly April alone, the sta­tion received over 600 ticks, and by May 19, it had received about a total of 2,300, he said.

Some days, Molaei said, the lab has been receiv­ing over 150 tick sub­mis­sions. Some­times more than 50% of the ticks in their lab test pos­i­tive for the bac­te­ria that caus­es Lyme.

Molaei said this winter’s con­di­tions were ide­al for tick sur­vival.

“First of all, the cold sea­son is what gets them,” he said. “But if we’re deal­ing with a cold win­ter asso­ci­at­ed with heavy snow, heavy snow acts as a warm blan­ket for ticks.”

Ticks have two- to three-year lifes­pans, Molaei said. This means that adult ticks over­win­ter under the snow­pack before emerg­ing in the spring to repro­duce. Dur­ing par­tic­u­lar­ly cold win­ters, or those with­out snow, a lot of them die, and that leads to low­er num­bers of Lyme cas­es in the spring.

The sta­tion report­ed that pos­i­tive cas­es of Lyme dis­ease iden­ti­fied in black­legged, or deer ticks, the most com­mon vari­ety in Con­necti­cut, increased 9% between 2024 and 2025. In 2024, 905, or 27%, of ticks test­ed pos­i­tive for the bac­te­ria that caus­es Lyme. In 2025, 1,465, or 36% did.

In 2023, the last year data was avail­able, Con­necti­cut saw 3,239 human cas­es of Lyme dis­ease, accord­ing to the U.S. Cen­ters for Dis­ease Con­trol and Pre­ven­tion. In 2010 and 2011, there were rough­ly 3,000 cas­es report­ed each year.

But from 2011 to 2019, annu­al cas­es saw a sharp decline. In 2019, before report­ing was skewed by the COVID-19 pan­dem­ic, data showed there were 1,233 cas­es in Con­necti­cut. That means the state saw a 163% increase from 2019 to 2023, a dif­fer­ence of 2,006 cas­es.

Jamie L. Can­toni, an agri­cul­tur­al research tech­ni­cian for the New Haven-based Con­necti­cut Agri­cul­tur­al Exper­i­ment Sta­tion col­lects a female black­legged tick, the most com­mon species in Con­necti­cut and com­mon­ly known as a deer tick. Pho­to by Alli­son Gol­len­berg

Dr. David Banach, an infec­tious dis­ease spe­cial­ist and epi­demi­ol­o­gist at UConn Health in Farm­ing­ton, said some of this increase could be due to changes in report­ing. Lyme dis­ease is chron­i­cal­ly under­re­port­ed, he said.

But envi­ron­men­tal fac­tors also play a role in the num­ber of infec­tions doc­tors see each year.

Jamie L. Can­toni said she’s nev­er had Lyme dis­ease and rarely finds ticks on her­self despite work­ing as an agri­cul­tur­al research tech­ni­cian for the exper­i­ment station’s active tick sur­veil­lance pro­gram. Part of Cantoni’s job is to col­lect ticks from around the state through a process called drag­ging. Drag­ging for ticks involves run­ning a square of can­vas through edge areas and check­ing it for the bugs every 25 meters, said Can­toni, who was recent­ly drag­ging for ticks just off Horse­barn Hill in Storrs. Any ticks the drag picks up are stored in vials, labelled and brought to the sta­tion for research.

Increased res­i­den­tial devel­op­ment in wood­ed areas since the pan­dem­ic is also a fac­tor dri­ving infec­tion, she said, since ticks and humans both like to hang out in areas where lawns and wood­lands merge.

“A lot of it is envi­ron­men­tal. A lot of it is peo­ple now. They move,” said Dr. Justin Radolf, an infec­tious dis­ease doc­tor who works with the Uni­ver­si­ty of Connecticut’s Lyme Dis­ease Research team. “They build hous­es in areas that every­body wants to be in, in beau­ti­ful places. And that’s where the Lyme dis­ease is.”

Plus, Radolf said, chang­ing cli­mates have allowed both ticks and Lyme dis­ease bac­te­ria to increase their range. Even birds can catch and car­ry Lyme dis­ease, poten­tial­ly pick­ing up and drop­ping off ticks across large dis­tances, he said.

Ticks don’t hiber­nate, so since the last few win­ters have been milder, they’ve been com­ing out ear­li­er and infect­ing more peo­ple, Dr. Megan Linske, a vec­tor ecol­o­gist spe­cial­iz­ing in tick-host-habi­tat dynam­ics at the exper­i­ment sta­tion, said.

She said they can some­times even find hosts on warm days in Feb­ru­ary.

“Connecticut’s kind of this per­fect storm for black-legged ticks,” Linske said. Connecticut’s abun­dant pop­u­la­tions of mice and deer give ticks plen­ty of poten­tial hosts to latch onto and feed from.

“[A total of] 87 mil­lion Amer­i­cans live, work, or vaca­tion in Lyme-endem­ic areas,” Dr. Seth Led­er­man, CEO and founder of Tonix Phar­ma­ceu­ti­cals, said. “It’s spread­ing north. It’s spread­ing south. It’s spread­ing west.”

Drag­ging a light­ly col­ored square of can­vas called a drag behind her, Can­toni stops to check for and col­lect ticks every 25 meters, cov­er­ing 750 square meters per site. Pho­to by Alli­son Gol­len­berg

Led­er­man said Tonix, a com­pa­ny based in Chatham, New Jer­sey that devel­ops treat­ments for chron­ic, rare and infec­tious dis­eases, is devel­op­ing a vac­cine that kills the bac­te­ria that caus­es Lyme before it even leaves the tick’s gut.

“Most vac­cines mean that the dis­ease you get is milder than if you didn’t get the vac­cine,” Led­er­man said. “This one, it lit­er­al­ly blocks– it kills the Bor­re­lia before it gets into your sys­tem.”

Bor­re­lia is the bac­te­ria which caus­es Lyme dis­ease. Led­er­man said the injec­tion of Bor­re­lia anti­bod­ies has been in the works at the Uni­ver­si­ty of Mass­a­chu­setts for the last ten years.

The vac­cine could be avail­able by 2030 and would be pre­scribed at doc­tors’ dis­cre­tion, Led­er­man said. One dose would be effec­tive for rough­ly four months. He expects it to be most fre­quent­ly used by peo­ple who spend a lot of time out­doors, like hik­ers, gar­den­ers and land­scap­ers.

A dif­fer­ent Lyme vac­cine, LYMEr­ix, was avail­able from 1998 to 2002, Dr. Paulo Ver­ar­di, head of UConn’s depart­ment of Virol­o­gy and Vac­ci­nol­o­gy, said. He said it was ulti­mate­ly dis­con­tin­ued because of low demand and con­tro­ver­sy over safe­ty con­cerns.

Led­er­man said Tonix’s vac­cine was about 95% effec­tive in pri­mate tests. Anoth­er vac­cine, in devel­op­ment by Pfiz­er, is about 70% effec­tive, accord­ing to a press release from the com­pa­ny.

But despite its poten­tial, Ver­ar­di said, a vac­cine is not a catch-all solu­tion. To real­ly con­trol tick­borne dis­eases, he said, there needs to be more land man­age­ment, pub­lic edu­ca­tion and a drop in the over­all tick pop­u­la­tion.

Linske said when it comes to keep­ing ticks off their prop­er­ty, peo­ple should know that many spray treat­ments can harm the ecosys­tem. As a solu­tion, she said, her team has been work­ing with pes­ti­cide treat­ments that tar­get tick and mite pop­u­la­tions in the fall. This means they can elim­i­nate ticks with­out harm­ing ben­e­fi­cial insects, like bees, but­ter­flies and oth­er pol­li­na­tors that are most active in the spring, she said.

“I feel like peo­ple get freaked out by ticks and tick-borne dis­eases, and then they’re like, I’m nev­er going out­side again,” Linske said.

But the best thing peo­ple can do, she said, is to be mind­ful of their sur­round­ings when they’re out­side and check them­selves for ticks once they’re back in.

“Go out and enjoy them, but just be aware of where you are,” she said.

Tick sea­son typ­i­cal­ly peaks in May and June. But regard­less of the date, Ver­ar­di said, ticks will be out when the sun and the peo­ple are.

“If I were to go out­side, it would take me less than five min­utes to find a tick,” Ver­ar­di said. “Or, I should prob­a­bly say that it would take less than five min­utes for the tick to find me. Because that’s what they’re good at.”