By Susannah Wood
Photos by Bruce Frisch

On Saturday, Aug. 10, Eliza Little gave the annual Ted Byers lecture at the Doolittle Club in front of a standing-room-only audience. The lectures are free and open to the public. Little, a postdoctoral researcher at the Connecticut Agricultural Experiment Station in New Haven for the past two years, has been studying ticks and the pathogens they carry, a natural segue from her doctoral thesis exploring mosquito-borne diseases and how landscapes affect their distribution. For now, her research relies primarily on submission of ticks to the CAES and reporting of infections rather than direct collection of field data.

Ticks have a long history in the world, 200 to 400 million years versus five to seven million years for humans, and are found on every continent. Their saliva is a rich soup of anesthetics, antihistamines and anticoagulants. Though very few tick species are of concern to humans, tick-borne disease is now a global problem. In most of Connecticut, at least for right now, we really only need to worry about the black-legged or deer tick, which can transmit the worm-shaped spirochete (Borrelia burgdorferi) that causes Lyme disease as well as the pathogens that cause anaplasmosis and babesiosis. The American dog tick can carry Rocky Mountain spotted fever, but only seven cases were reported in the state, and those may well have been acquired elsewhere. That said, other ticks of concern, like the lone star tick, are beginning to show up in a few counties on the southern coast and may become more problematic in the future.

Lyme disease is the third most common bacterial disease after chlamydia and gonorrhea. Reported cases in the United States have tripled since 1991 to 35,000 in 2016. The Centers for Disease Control estimate that reported cases represent only about a 10th of actual cases, meaning that about 350,000 people had the disease in 2016.

The black-legged tick has a two-year life cycle. In early spring the female tick lays around 2,000 eggs that hatch into larvae. The larvae are not born infected but may become so after a blood meal from an infected host. They molt into nymphs, most numerous in June and July in Connecticut. The nymphs take a blood meal from small mammals, deer, humans or birds and molt into adults by the end of summer. While only 26 percent of nymphs in the state are infected, their tiny size means they are often missed and so account for the highest rates of infection with Lyme disease. Adult ticks consume their biggest blood meal on a large, two- or four-legged mammal before mating and laying eggs.

The white-footed mouse is a “reservoir host” for the Lyme spirochete, meaning the mice serve as the source of infection (along with other small animals like birds and chipmunks). White-tailed deer are termed “amplifying hosts” because the ticks get a big blood meal from them. They do not infect the tick with B. burgdorferi, but may pass on other pathogens to other species of ticks.

Ticks and deer vanished from New England by the late 19th century owing to farming and charcoal manufacture. It’s likely that a remnant population of deer and ticks remained in Long Island. Once the forests began to return, deer and ticks did too. Unfortunately, climate change with its warmer winters is likely to increase populations of the black-legged tick and expand the range of new tick species in Connecticut. Our landscape of houses in the midst of small forest patches creates ideal habitat for both deer and ticks.

Once a tick latches on, finding it quickly and removing it safely remains the best protection against disease, since it takes more than 24 hours for the spirochetes to make their way to the tick’s salivary glands. The other common tick-borne diseases in our area have a similar pattern of delayed infection. 

While the chances of a human vaccine are dim at the moment, scientists are working to develop ways to treat the mammalian carriers, both to kill off the ticks and to vaccinate them against the disease. A new spray that contains a tick-specific fungus could offer effective treatment for people’s yards, which is where most infections occur, especially at the forest edge or near stone walls. Spraying clothing with permethrin or buying clothing treated with the pesticide provides good protection that lasts for a number of washings. Clearing away Japanese barberry and multiflora rose around your house has been shown to reduce the presence of infected ticks and mice. Setting bait boxes to kill mice is not a good idea, since the poison migrates into the very predators that keep mice in check. 

There is still a lot we don’t know about Lyme disease. Little pointed out that, in view of its debilitating effects, increasing infection rates and expanding range, research has been woefully underfunded. She hopes that a recent report by the Tick Task Force may increase federal investment. Needs include active collection of field data, understanding increasing rates of co-infection, developing integrated management practices to reduce rates of infection in animal hosts. More funding is also needed to investigate the causes and treatment of Post Lyme Disease Treatment Syndrome, which affects 10 to 20 percent of patients.

While Little refuses to let the threat of disease keep her and her family out of the woods, she is thinking about buying permethrin-treated socks. 

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Tick Check List

• Learn your ticks.
• Wear light colored pants and tuck into socks. Tuck in shirt too!
• Spray pants and shoes with DEET or other tick repellant: https://www.epa.gov/insect-repellents/find-repellents-right-you.
• While walking in ticky areas, check your pants frequently. Don’t wait to get home.
• Put clothes right into dryer on high heat for 20 minutes.
• Comb out hair with a fine-tooth comb.
• Shower and do a tick check. Don’t forget groin, armpits, scalp.
• If you find a tick embedded, don’t panic. Remember you have 24 hours to remove a tick before it can transmit Lyme disease or the other two main diseases in our area.

• Keep a tick-removal tool handy. Needle-pointed tweezers are best.
• Grasp tick as close to the head as possible and pull straight out.
• Rub area with alcohol.
• Send engorged ticks or any lone star ticks to CAES. Check here for instructions: https://portal.ct.gov/CAES/Tick-Office/Tick-Office/Information-on-Submitting-Ticks.
• If you develop flu-like symptoms, the bull’s-eye rash or aching joints, contact your doctor.