An increase of Lyme disease cases in Michigan has highlighted the importance of tick surveillance, public health officials say.
Blacklegged ticks (commonly called deer ticks, have increased in Michigan, according to Andrew Cox, the director of the Macomb County Health Department. The greater the tick population, the larger the chance of exposure to Lyme disease for humans.
More and more ticks are being found in gardens and backyards, said Rachel Burkholder, a vector-borne disease epidemiologist at the Michigan Department of Health and Human Services. The rise of ticks can be caused by the migratory patterns of their deer, bird, and squirrel carriers, she said.
To monitor tick-borne diseases, the state health department created a vector-borne disease surveillance project. A vector-borne disease is one that's transmitted by a living organism.
This year, 26 counties are involved in tick surveillance. Surveillance consists of tick dragging, where a square-meter-sized cloth is pulled over fallen leaves and grasses along hiking trails, parks, and any place where people are doing recreation outdoors. The ticks catch onto the fabric and get sent to the CDC to be tested for pathogens and determine how many are carrying disease.
Blacklegged ticks are the primary carriers of Lyme disease. Cox said that nymph blacklegged ticks, which are not yet adults, can be hard to spot. “That’s a challenge for us in public health because they are really the size of a poppy seed," he said. "They can really blend in.”
It takes around 24 to 36 hours for Lyme disease to pass from a tick to a human once a tick attaches, Burkholder said. The longer a tick stays on a person without being spotted, the more likely it is that the individual will contract the disease.
The peak season for tick surveillance and movement is in the months of April through September, Cox said. But adult blacklegged ticks can be active any time that temperatures are above freezing, according to Burkholder. "I still get citizen reports of ticks in December, January, February. So, it's really important that people know that,” she added.
Cox said the persistence of tick reports into winter months is likely because of climate changes. With Michigan winters growing shorter and warmer, ticks are less likely to be killed off.
Common symptoms of early stage Lyme disease — the first 30 days after the illness is contracted — include a bulls-eye rash, headaches, fatigue, muscle aches, and joint pain and swelling. Once caught, it is easily treatable through antibiotics. However, late-stage forms of the disease can result in an inflammation of the brain, heart problems, meningitis, and nerve tissue damage.
To protect against ticks, the state health department recommends using EPA-registered repellents, wearing light colored clothing, staying on well-groomed trails, performing regular tick checks, and showering after being outdoors.
Residents can also submit photos of a tick to get the species identified and submit it for testing by the state. Additional information about this process can be found on the MDHHS website.
