Mosquito-borne virus prevention in effect across Michigan
BAY CITY, Mich. (CBS DETROIT) - Summertime means mosquito season in Michigan, especially with the wet weather across the state.
So far this year, two Michigan residents tested positive for the Jamestown Canyon virus. In the southern U.S., malaria has been detected for the first time in 20 years.
In Michigan, work is being done at the state and local levels to prevent mosquito-borne diseases. But experts say mosquito season is changing as temperatures in Michigan continue to rise.
Rebecca Brandt, the manager of Bay County Mosquito Control, has worked in the field for 20 years. Their program was started in the 70s after an outbreak of St. Louis encephalitis.
Brandt said the goal is to protect public health and improve quality of life by reducing mosquitoes.
"Control mosquito larvae before they're biting, flying adults. It's more efficient, it's more economical to do it that way."
After a rain event, Bay County Mosquito Control Operations supervisor Ken Misiak and his team have about seven days to find and treat mosquito larvae before they become flying, biting adults.
They inspect standing water, like roadside ditches and flooded fields. As well as high-population areas like parks and campgrounds. They look for mosquito larvae and pupa, then treat those areas and send samples to the lab.
In the lab, biologists like Kristy Engrstrom trap, count, and sort adult mosquitoes.
"These are Psorophora ferox. And they actually have little white boots on the end of their hind femur, or hind legs," said Engstrom.
The biology department sets 90 different mosquito traps each week. Each trap can catch up to 10,000 mosquitoes.
"Our host-seeking mosquitoes are attracted to carbon dioxide," said Engrstrom. "So, we'll hang dry ice next to it, and that dry ice will attract the mosquitoes. And then they'll fly around here, and as they fly over, they'll get pulled into our bag here."
She said without this constant monitoring, mosquitos could spread viruses quickly.
"Just one of these little guys could have a virus in them. And it just takes one bite and you've got a potentially deadly virus in your system."
To test for those viruses, the sorted mosquitoes are sent to the Michigan Department of Health and Human Services. Twenty of those tests have come back positive this year.
"Right now until about the end of the fall is actually the busy season for diseases, but not so much for visibly biting mosquitoes," said state medical entomologist Emily Dinh.
This year she has seen mosquitoes with West Nile, EEE, and Jamestown Canyon virus. There have also been two human Jamestown Canyon virus cases.
Brandt said that while the viruses are rare, the risks are real. Adding that Michigan's milder winters mean new species of mosquitoes coming into the state, bringing with them new viruses.
"Even over the past 20 years that I've been here, I can see the mosquito seasons getting longer because we're not getting a hard cold frost at the end of September."
She said their work has also changed, as they have a bigger focus on their impact on the environment.
"Using a lot of green products, organic products, bacterial products is really the primary focus of any larval control that we do. And making sure when we do use chemical products that we're using the least amount that can be effective," said Brandt. "We aren't doing treatments just because it's a Tuesday. We're doing a treatment because there is a need for it. And we've got the data to document that."
Brandt said mosquito control will only become more and more important in the future.
"We expect this to keep growing. Especially as we see more mosquito species and more viruses coming into Michigan. Then the need to do more mosquito control is likely to increase."
Emily Dinh said there are over 60 different species of mosquitoes in Michigan. Some bite horses, birds, worms, or humans.
"Just because you don't see the biting mosquitoes or feel them biting you or have itchy bites. That doesn't mean they aren't out. They are out," she said
While work is being done at the local and state level, each Michigander can play their part. She said the key is not creating environments where mosquitoes can thrive.
Her motto is "tip and toss" standing water, including gutters, dog bowls, and bird baths.
