Ask the Expert: Avoiding ticks and preventing tick-borne diseases
June 17, 2020
Jean Tsao is an associate professor in the Department of Fisheries and Wildlife in the College of Agriculture and Natural Resources. She and her colleagues developed a mobile health app, The Tick App, that informs users how human behavior affects tick bites. Tsao answers questions on ticks and tick-borne disease prevention.
Q: How can people avoid tick bites while enjoying the outdoors? Is there any proper attire or bug spray to use?
A: There are generally three principles with various options to carry out: avoid tick habitat; use an EPA-approved repellant following the manufacturer’s instructions (most of the ones approved for mosquitoes are approved for ticks; just check the label; it will say); conduct thorough tick checks.
I would do it when you’re recreating/working in tick habitat, before you get back in your car — check yourselves as well as your pets — and then do another through check when you take a shower/bath within two hours of coming back from recreating/working in tick habitat.
There is one more thing you can do to reduce any loose blacklegged ticks from later finding you/others/your pets: Put your clothes that you wore directly into the dryer for ten minutes on high heat to kill ticks.
Q: What should we do if we find a tick on us? What’s the proper removal process?
Don’t panic! Carefully grab it with tweezers at the point closest to your skin to remove it. Then, take a clear photo and submit it to The Tick App so the team can identify the species.
Afterwards, put the tick in a plastic bag labeled with the date and geographic location where you think you may have contacted it; then, store it in your freezer.
If you start feeling ill, go to a doctor and show them your tick. The species and degree of swelling can help with diagnosis and treatment.
Q: What are telltale signs of Lyme disease or other tick-borne illnesses?
A: Not being a medical worker, I’m not comfortable answering this question, so I suggest looking to the links on the CDC website. But, I would comment that my impression is that many people who have tick-borne illnesses experience general “flu-like” symptoms — fever, malaise, achiness, which is why they might be difficult to diagnose as a particular tick-borne disease.
Q: Why/how do ticks and tick bites lead to Lyme disease?
A: People can become infected with the agent of Lyme disease, Borrelia burgdorferi, if they are bitten by an infected tick.
There are three stages of ticks that look for a host so that they can get a blood meal: the larva (baby), nymph (teenager) and the adult female (adult). The larva needs a blood meal in order to become a nymph; the nymph needs a blood meal in order to become an adult; and an adult female needs a blood meal in order to lay eggs. The adult male doesn’t feed so does not need a blood meal.
The larva hatches uninfected — so it’s through the bloodmeal from an infected host, that it acquires Lyme disease bacteria. Then when it molts to become a nymph, the bacteria survive the developmental process and the new nymph that emerges carries the bacteria in its gut. When the flat, infected nymph finds a host and feeds, the bacteria in the gut multiply — then they break out of the gut, swim through the hemocoel of the tick (where the tick’s blood bathes its organs), invades the salivary glands, and then gets injected into the host.
This is why it is so important to try to find and remove ticks as soon as possible. Even if the tick has attached, if it’s < 36 hours of feeding, you’re very unlikely to become infected. If the tick has fed > 72 hours, you’re much more likely to become infected and experience signs of disease.
Q: What are the chances of getting Lyme disease from a tick, and what are the chances of being bitten at all?
A: Not all tick species transmit the Lyme disease pathogen. Your chances of getting Lyme disease from a tick depends geographically. More than 95% of cases of Lyme disease in the U.S. are caused by the blacklegged ticks distributed among the states in the Northeast, Mid-Atlantic and North Central regions.
In these regions, ~20-30% of blacklegged nymphs are infected and ~40-60% of adult females are infected. But, as stated above, even if an infected tick bites you, if you can remove it before it has fed > 36 hours, your chances of becoming sick are very low.
Q: What time of day are they most active? Where do they often hide?
A: These ticks are active day and night if it’s warm enough, but if it becomes too dry, they become less active. Ticks are prone to dessication, and so if it’s dry, they hunker down below the leaf litter, where it’s more moist, and re-hydrate and conserve energy.
Research from the 80s suggests that adult and nymphal ticks were the most active during their study, which was from 6 a.m. – 9 p.m., but most active from 6 a.m. - noon. But the fact that you can find blacklegged larvae and nymphs on wildlife that are nocturnal, diurnal and crepuscular tells you that the ticks are active all the time.
The American dog tick is a tick that is can be found in woods, but can survive and do well in grassy areas, too. Lone star ticks also are more associated with wooded areas, but they can be found in areas outside woods.
Q: How can people create a tick-free zone around a camping area or campsite? And subsequently how can people avoid bringing them back home?
A: Knowing that ticks are associated with leaf litter and vegetation, I would recommend people to place their campsite in a more open area within the designated campsite — not right up against the vegetation.
It won’t be tick free, but at least for blacklegged ticks, they do not tend to crawl out from the vegetation towards people.
And, just as one can treat clothes and shoes, one can also treat camping gear with permethrin, which will prevent you from bringing ticks home. Permethrin can stun and/or kill ticks on contact and so if they get on clothes/gear, they will fall off, and potentially die.
But, one should always inspect their gear before packing up everything regardless if you use permethrin.
For more information about ticks, visit CDC.gov.