The number of tick-borne illnesses diagnosed in the United States doubled between 2004 and 2016, according to a recent report from the Centers for Disease Control and Prevention. Summer is prime tick season, and people spending time outdoors should be vigilant, says University of Illinois entomology professor Brian F. Allan. An expert in the spread of insect- and tick-borne diseases, Allan discussed ticks in Illinois and how to prevent bites in an interview with News Bureau biomedical sciences editor Liz Ahlberg Touchstone.
The recent CDC report showed the incidence of tick-borne illnesses is rising. Are tick populations increasing? If so, why?
Yes. The increase in tick populations and tick bites likely is driven by several factors, including changes in climate and land use that have facilitated the spread of ticks and associated diseases. More people are living in close proximity to natural areas. Increased residential development in previously undeveloped areas puts people in close contact with ticks and creates additional opportunities for exposure to tick-borne diseases.
What kinds of ticks do we have in Illinois, and what kinds of diseases can they carry?
While there are dozens of tick species in Illinois, the three encountered most commonly are the black-legged tick (also known as the deer tick), the American dog tick and the lone star tick. There are important diseases associated with each, and most begin with a rash or flu-like symptoms. The black-legged tick is best known as the vector of Lyme disease, but also can transmit anaplasmosis and babesiosis. The American dog tick primarily is responsible for the transmission of Rocky Mountain spotted fever. The lone star tick carries a number of emerging diseases, such as ehrlichiosis, as well as the Heartland and Bourbon viruses.
Where would someone be likely to pick up a tick? If I’m not in a wooded area, am I safe?
Depending on the tick species, people and their pets tend to pick up ticks in grassy areas like fields or meadows as well as in wooded areas. Some people even may encounter ticks in their yards, especially if they live close to natural areas.
What are some ways to prevent tick bites?
I recommend three strategies for tick bite prevention if going into areas where tick encounters are likely. First, use clothing to make a continuous barrier – tuck your pants into your socks and your shirt into your pants. Try to limit the number of openings in your clothing that a tick could crawl through. Second, use repellents, especially those containing permethrin. You can buy clothing already treated with permethrin, and recent research has shown this is highly effective in deterring ticks.
Third, perform a thorough tick check when you get home and remove immediately any ticks that may have attached themselves to you. This combination of strategies is very effective for preventing tick-borne disease in humans. And for pets, use tick prevention treatment prescribed by a veterinarian.
What should someone do if they find a tick on themselves, a family member or a pet?
The good news is that it can take hours for a tick to attach and start feeding, so often there is time to remove the tick before it can transmit a disease. The best method for tick removal is to grasp the tick with tweezers close to your skin and apply slow, steady pressure until it detaches. I’ve heard a lot of other methods described for tick removal, but this is the safest and preferred option. Don’t burn the tick or try another method that gets the tick to release on its own, as it can increase the probability of disease transmission.
If someone has been bitten by a tick or has symptoms of a tick-borne illness, when should they seek medical attention?
Not all ticks are carrying a pathogen, so being bitten by a tick is not necessarily a cause for alarm. But if a person is bitten, they should monitor their health closely for several weeks afterward. If a rash or flu-like symptoms develop, the person should seek medical attention as soon as possible, since some tick-borne illnesses can progress rapidly.