The Zika virus was recently found in a type of mosquito commonly found in the United States.
Even with the discovery of the virus in the Culex family of mosquitoes by Brazilian researchers, there are still significant questions about how effectively they could spread the disease even if Zika-carrying offspring were buzzing around somewhere like Minnesota.
“Just finding it in the mosquitoes doesn’t mean anything on its own,” said Dave Neitzel, Minnesota Department of Health’s supervisor in the vector-borne disease unit. “We need to learn how effective they can be in transmitting the viruses.”
For one, the Culex genus of mosquitoes includes many different species. The one carrying Zika in Brazil could be far different than ones found in the United States. Plus, some don't even feed on humans and, therefore, would be of little concern even if they did carry the Zika virus.
In Minnesota, there are 51 species of mosquitoes. Some which do fall in the Culex family mercifully choose other creatures to annoy, such as birds. Others carry different risks, especially this time of year.
“Certainly we want people to not just be focused on Zika, because there are other diseases circulating in mosquitoes,” Neitzel said.
People are most at risk for those illnesses — West Nile virus and La Crosse encephalitis — in the latter, muggy part of the summer.
West Nile virus is actually spread by another Culex mosquito, Culex tarsalis. The warmer the year, the higher the risk of mosquitoes carrying the virus.
“I watch our current warm weather streak with interest here because I just know the virus is growing in mosquitoes,” Neitzel said.
La Crosse encephalitis is caused by bugs in the Aedes family known as tree hole mosquitoes. Other Aedes mosquitoes, aegypti and albopictus, are the ones primarily carrying the Zika virus.
Tree hole mosquitoes thrive in wooded areas during daylight hours, which makes them a potential concern in the lush Minnesota River Valley. Neitzel said in the mid-2000s his team found evidence of La Crosse encephalitis-carrying mosquitoes in the Mankato area.
“It’s definitely out there and we want people to protect themselves, especially their children playing in wooded areas,” he said.
Bug spray seems to be the best measure against mosquitoes no matter what disease they may or may not carry. Neitzel said it's a safe bet to spray down if you plan to be outside during peak mosquito hours from now until the end of summer.
“Any residents in your area out at dusk and dawn, they should consider wearing repellent because risk will be high,” he said.