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Ticks and mouse poop greet Michigan residents as summer arrives

blacklegged tick
As if an ever-worsening tick season isn’t bad enough, Michigan now has diagnosed its first-ever case of Sin Nombre hantavirus, which can be passed by infected rodents. (Shutterstock)

After nearly 15 months staying close to home, Michiganders are finally ready to venture back out as concerns over the COVID-19 pandemic fade and life bubbles back to normal on summer’s doorstep.

But has anybody told the ticks? 

Or the mice?

Michigan residents are being accosted by an army of ticks as they head into the woods. Some of those ticks carry Lyme disease, which can be passed to humans through bites.

And if an army of Lyme disease-carrying ticks isn’t enough to send you scurrying back indoors, the state announced Monday the first confirmed human case of Sin Nombre hantavirus in Michigan — an often-fatal illness borne from the fluids of infected rodents, typically mouse poop. The disease is more frequently found in the American Southwest.



Ticks are more prevalent this year than in the past, but Michigan may need to get used to it. Climate change is expanding the region in which ticks thrive.

“This year, it seems like the dog tick has gone bonkers,” Jean Tsao, an associate professor in the fisheries and wildlife department at Michigan State University, told Bridge Michigan Monday. Its cousin, the blacklegged tick, is the species that bites humans, and signs point to there being lots of them this year, too, Tsao said.

Not all ticks carry Lyme disease, but the disease does spread quickly.

“It’s kind of like a fire — it takes a little bit before it starts to smolder …but it eventually becomes stable and increases to a higher level,” Tsao said, explaining how Lyme spreads through a tick population.

A warming climate has allowed ticks to spread northward into the lower peninsula from Indiana, Tsao said. Longer summers and warmer winters allow the population to explode.

Tsao recommends a tick app Michigan residents can download to help researchers track the parasites this summer.

A 40-percent mortality rate

The Michigan Department of Health and Human Services on Monday announced the first confirmed case of Sin Nombre hantavirus in the state in a Washtenaw County woman The virus can cause hantavirus pulmonary syndrome (HPS), a rare but severe disease with a fatality rate of 40 percent.

The Sin Nombre hantavirus is transmitted by the saliva, urine or excrement of white-footed mice and deer mice. Humans are at greatest risk of exposure when entering or cleaning rodent-infested structures, because the disease is typically contracted by ingesting contaminated food or water, inhaling freshly dried rodent excretions or having them come in contact with open skin. Rodent bites can also transmit hantavirus.

“All the disinfectant you have left over from the pandemic — use that to spray mouse droppings.” — Mark Sheperdigian, Rose Pest Solutions.

“The most typical place to get hantavirus is in an unused junk drawer in your garage in suburbia,” said Mark Sheperdigian, vice president of technical services at Rose Pest Solutions in Troy.

Symptoms of HPS can include fever, chills, body aches, vomiting, diarrhea and abdominal pain, among others. Advanced cases can progress to include coughing and shortness of breath. A 2013 study in PubMed Central found that of 624 hantavirus cases documented in the U.S. in the past 20 years, 96 percent occurred in states west of the Mississippi River.

Susan Ringler-Cerniglia, a public information officer with the Washtenaw County Health Department, said dogs and cats cannot transmit the virus to humans.

To reduce the risk of infection, people cleaning areas with rodent infestations should take safety steps like ventilating the space for 30 minutes before working, wetting areas with a disinfectant before cleaning and wearing properly-fitted gloves.

“All the disinfectant you have left over from the pandemic – use that to spray mouse droppings,” Sheperdigian said.

According to the Centers for Disease Control and Prevention, rodents can transmit a host of diseases, not just the hantavirus. They include hemorrhagic fever with renal syndrome, salmonellosis and the plague.

Consider taking the following precautions to protect yourself and your loved ones against what lurks in the great outdoors (and, apparently, indoors).

For ticks:

  • Stay on designated trails while hiking, and always carry EPA-registered repellant.
  • After outdoor activity near a tick habitat, be sure to check your hair, skin and clothes for the insects — check your pets, too. You can also hop in a hot shower and throw your clothes in the dryer for 10 minutes following tick-adjacent activity to reduce the risk of finding an attached tick. 
  • If you are bitten by a tick, try not to freak out. First, grab a pair of tweezers and remove the tick from your skin. Next, place it in a plastic bag labelled with the date and location of your tick-adjacent activity. Store it in the freezer, and if you begin to feel sick, bring it to your doctor for diagnosis and treatment.

For rodents:

  • Inspect your home for gaps and holes rodents could enter through, and seal them up, no matter how small. Common holes are found around windows and doors, in roofs and near electrical lines. Also be cognizant of spaces in and around your home where rodents  typically seek shelter, such as tall grass and weed-infested gardens, old tires and piles of newspapers and bottles in the yard. 
  • Keep your home clean: Rodents will eat nearly anything if given the opportunity. This includes garbage, dog poop, pet food and even bird feed. Rinse containers before you recycle them and don’t leave food outside for stray animals. Also, try to bring trash to the curb closer to pick-up time, giving rodents less of an opportunity to strike.
  • If you suspect you have a rodent infestation, there are several steps you can take. First you must clean up the scent trail rodents leave, which they produce to attract other vermin to the site. Do not stir up dust by sweeping droppings or urine, but rather use a disinfecting solution on the affected area before picking up materials with a plastic bag. If the issue persists, obtain snap traps or contact a pest control company.

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