04/12/2026
Scientists sound alarm on ticks
carrying Lyme, other diseases
By Stephen Underwood
Hartford Courant
Scientists with the Connecticut Agricultural Experiment Station say they are seeing an increasing number of ticks testing positive for Lyme disease this year, a concerning trend for anyone looking to enjoy the outdoors this spring.
“During the past few weeks, we have received an average of 30 tick submissions per day for testing, and greater than 40% have tested positive for Lyme disease spirochetes. In addition, these ticks have tested positive for the pathogens responsible for babesiosis, anaplasmosis and Borrelia miyamotoi disease,” said Dr. Goudarz Molaei, director of the CAES tick testing program. “We are at the beginning of the tick activity season for adult blacklegged ticks, which often have higher infection rates because they have had two chances to acquire disease agents during their juvenile stages (larva and nymph),” Molaei said.
In March, scientists with the CAES announced that more than 10,000 ticks were collected from 40 publicly accessible locations across all eight Connecticut counties during the spring, summer and fall of 2025. The ticks were then tested for five human disease-causing pathogens including anaplasmosis, babesiosis, Lyme
disease, hard tick relapsing fever and Powassan virus. Scientists said the number of ticks collected was higher than in previous years, showing a rise in the tick population. New London County reported the highest average adult blacklegged tick density, with around 81 ticks per acre, and Litchfield County reported the highest average nymphal tick density, around 28 nymph ticks per acre. Nymphs are ticks that have not fully matured and are often the size of a poppy seed, making them hard to detect.
Treatment and prevention According to the Centers for Disease Control and Prevention, Lyme disease is the most commonly reported vector-borne disease in the United States, affecting an estimated 475,000 people annually and causing potential damage to the joints and nervous system. “One of the biggest issues of Lyme disease in Connecticut is that there are a lot of symptoms that are attributed to Lyme, that aren’t necessarily Lyme,” said Dr. Ulysses Wu, chief epidemiologist at Hartford HealthCare. “It’s
both an over-diagnosed disease, because the testing is not perfect for it, it’s also a vastly under-diagnosed disease as well because a lot of people aren’t tested for it.”
Wu said that most patients with Lyme disease often display the characteristic bullseye rash, but not all who are infected will develop it. He said the most important thing is doing a tick check after spending time outdoors. Some of the first signs of Lyme disease include mild fever, joint aches, muscle pain, fatigue and headache. The first stage of Lyme disease is called “early localized disease” followed by early disseminated disease, which occurs a few weeks to a few months after an infected tick bite. This stage, while more serious, can affect the central nervous system and the heart, Wu said. “Before we didn’t always prescribe anti-microbial prophylaxes every time someone had a deer tick bite, but it’s much more common nowadays, because people don’t want to take the risk,” Wu said. “If you find a tick on you, the first thing to do is find out if it’s a deer tick. There are plenty of other ticks in Connecticut that don’t transmit Lyme. If it is a deer tick, it needs to be on you greater than 36 hours, and we can judge that by the rate of engorgement. If that’s the case, then we generally start prophylaxes within 72 hours.” Common antibiotics used to treat Lyme disease include doxycycline, amoxicillin, and cefuroxime. Early, prompt treatment with these antibiotics is highly effective, Wu said.
The state’s Department of Public Health reported 2,170 human cases of Lyme disease in Connecticut in 2024. While there are no currently approved human vaccines for Lyme disease, Pfizer recently announced the results of a clinical vaccine trial that demonstrated 70% efficacy in preventing Lyme disease in individuals aged 5 years old and above. The drug maker said they will now seek FDA approval for the vaccine. A human vaccine for Lyme disease was approved by the FDA in 1998. Called LYMErix, it was the first and only licensed vaccine for Lyme disease, developed by SmithKline Beecham. But it was discounted shortly after due
to low demand, safety fears and lawsuits, according to Wu.
“This is a very promising development,” Wu said. “Believe it or not, there was a vaccine in 1998, but it was discontinued because of poor sales. But there is a difficulty in making one because of the complexity of the bacteria. The Pfizer oner seems to be quite promising and expected this year. So this is a really big
development for Lyme disease.” Ticks carry more than Lyme
Molaei said several other tick species found in Connecticut carry babesiosis and human granulocytic anaplasmosis. Hundreds of ticks were found to be positive last year, but the “actual number of disease cases could be nearly 10 times higher.” Babesiosis, transmitted by blacklegged ticks, can cause flu-like symptoms — fever, chills, fatigue and muscle aches — and can be severe or fatal in older adults or those with weakened immune systems, according to scientists.
“Using tick repellents when hiking or camping and conducting tick checks remain the best ways to reduce the risk of contracting tick-borne diseases,” said Dr. Jason White, director of the CAES. “Connecticut residents are also encouraged to submit ticks they have removed from their bodies to our laboratory for species
identification and testing. This allows them to make informed decisions concerning diagnosis and treatment in consultation with their healthcare providers.” Connecticut also has several non-native tick species that have established populations in the state, according to Molaei.
The lone star tick, mostly native to the southeast portion of the United States, was first discovered in 2017. It was found in Fairfield and New London counties in 2019. The tick, while not a carrier of Lyme disease, is known for its unusual ability to make some people develop a red meat allergy. Alpha-gal syndrome, also known as mammalian meat allergy, is a tick-borne allergy to a sugar molecule called alpha-gal, triggering delayed reactions to ingesting red meat. Longhorned ticks, which are also now considered established in Connecticut, are not native to the United States and are considered an exotic species. They originally were found in tropical environments in Asia and often don’t bite humans, but there have been documented reports of humans being bit by them in Connecticut, according to CAES. They are unusual for their ability to reproduce primarily through parthenogenesis, a form of asexual reproduction where females lay eggs without mating. “In addition to pervasive populations of blacklegged and American dog ticks, Connecticut has established populations of three invasive species: the lone star tick, Gulf Coast tick, and longhorned tick, primarily in the coastal areas of Fairfield and New Haven counties,” Molaei said.
“These ticks are capable of transmitting their own suite of pathogens responsible for ehrlichiosis, rickettsiosis, and Heartland virus, among others,” he said. The best way to remove a tick is to grasp it close to the mouth parts near the skin surface and with gentle, steady pressure, pull the tick upward away from the skin until it releases, Molaei said. Once the tick is removed, wash the area of the bite with an antiseptic or rubbing alcohol.
According to the Center for Disease Control, the best way to prevent tick-borne illness includes: Checking your clothing for ticks. Ticks may be carried into the house on clothing. Any ticks that are found should be removed. Tumble dry clothes in a dryer on high heat for 10 minutes to kill ticks on dry clothing after you come indoors. If the clothes are damp, additional time may be needed. If the clothes require washing first, hot water is recommended. Cold and medium temperature water will not kill ticks. Examining gear and pets. Ticks can ride into the home on clothing and pets, then attach to a person later, so carefully examine pets, coats and daypacks. Showering soon after being outdoors. Showering within two hours of coming indoors has been shown to reduce the risk of getting Lyme disease and may be effective in reducing the risk of other tick-borne diseases. Showering may help wash off unattached ticks and it is a good opportunity to do a tick check. Checking your body for ticks after being outdoors. Conduct a full body check upon return from potentially tick-infested areas, including your own backyard. Use a hand-held or full-length mirror to view all parts of
your body. Check these parts of your body and your child’s body for ticks.