Asian tiger mosquito. Image: Wikimedia Commons.
By Jack Nissen
Capital News Service
While Michigan health officials had a plan for combating the Asian tiger mosquito, it was untested.
At least, until mid-August when they caught a few in Wayne County.
Now that the mosquitoes, known for carrying the Zika virus, have been found in Michigan, health departments are taking more measures to fight their arrival.
“We’re probably going to be ramping up surveillance as well as monitoring Ohio and Indiana,” said Meghan Swain, executive director of the Michigan Association for Local Public Health, a nonprofit lobbyist for local health departments.
After the mosquito was found, an increased surveillance of the area in Wayne County was done twice in search for more.
“We’re in some ways, more prepared for this because of the funding we had at the beginning of the year,” said Erik Foster, a medical entomologist with the Department of Health and Human Services. “We had more preparation and understanding of the mosquito as a vector.”
The Wayne County Health Department spotted the mosquito in one of the traps put up every week in Livonia. They were breeding near a business location on I-96 in a shipment of containers, Foster said.
“They did a nice job,” said Eden Wells, the chief medical executive with the Department of Health and Human Services. “They have responded very well and I was very impressed with the way leadership of the Wayne County Health Department and the city of Livonia partnered with our state health folks to address this.”
Officials were on high alert after receiving notice a month earlier that the same species of mosquito was found in Toledo, Ohio–just across the border from Michigan.
“We weren’t that desperate, because everybody understood that Zika was going to be a problem and started preparing about two years ago,” Wells said.
This doesn’t mean the disease itself hasn’t shown up in Michigan. In 2016, there were 67 reported cases of Zika imported by people into the state.
The Zika virus, a disease that causes birth defects in children, entered the national spotlight after travelers to the 2014 World Cup in Brazil were warned about the outbreak. While they don’t travel very far on their own, they tend to make big hops in containers holding tires, Foster said.
While the Asian tiger mosquito isn’t in Kent County, mosquitoes that carry the West Nile virus are – and that’s prompting officials there to take similar measures. A warning was put out mid-September concerning five new cases of the disease.
“The reason we think that warning is important is because people need to know that West Nile is very present in the community,” said Steve Kelso, the marketing and communications manager for the Kent County Health Department. “People need to know this is active and need to be careful and take precautions.”
The tests Kent County does for mosquitoes that can carry West Nile are similar to the tests that counties use for Asian tiger. The Centers for Disease Control and Prevention (CDC) has partnered with 25 county health departments to set up traps to attract mosquitoes.
“We fully anticipated that we would need to be ready for when Zika showed up in the state a while ago,” Wells said.
That meant educating travelers about potential diseases and ways to avoid getting sick, while using a system in Michigan that she calls “enhanced surveillance” to look out for cases of the mosquitoes.
The health department has also identified airports and shipping ports where the disease could come in, increasing the number of tests for mosquitoes and making more efforts to remove places where breeding takes place.
Now that the species is here, the Department of Health and Human Services has been talking with the CDC about controlling and eliminating the species.
“These mosquitoes love standing water,” Wells said. “It’s important to try to control these mosquito pools to get rid of anything that might incite them.”
Sewer and drainage areas are popular places where water accumulates. Because a lot of Michigan’s industry is built around cars, Wells worries about old tire yards, which are considered an active surveillance site.
There is a connection between the Livonia spotting and tire pits, said Edward Walker, a Michigan State University entomologist.
“It is associated with the pile of tires that is accumulating in Livonia,” Walker said. “It’s not surprising to me because the tire trade is so common in Michigan, as well as the moderating of temperatures.”
As of 2015, the Department of Environmental Quality estimated more than 275,000 tons of tires were recycled or repurposed in Michigan..
About the same amount will be collected this year, said Aaron Hiday, an environmental quality analyst.
Scrap tire recyclers must treat them for mosquitoes, Hiday said. “Some set traps while others will spray a type of pesticide or cut holes in the tires.”
Many scientists are calling the growing trend of tropical viruses further north a result of climate change.
“We’re seeing the same trend with allergens and an increase in pollen count,” said Katie Parrish, the communications officer with the Michigan Environmental Council. “We’re seeing this as an indicator that climate change is real and we’re seeing those manifestations in our everyday life.”
With the warming of summer months, a shrinking of winter months and increased precipitation, Walker says we should see an increase in mosquito-borne illnesses as time goes on.
“We’re going to have to have the public and political will to intercept the problem before it gets worse.”