Mosquitoes caught in Windsor, Ont., had the potential to carry the Zika virus, but they posed no risk of infection, the local health unit reports.
Four Aedes albopictus mosquitoes — also known as Asian tiger mosquitoes — were found in a local mosquito trap during routine monitoring for West Nile virus in September.
“I want to go out of my way to say they weren’t infected with Zika virus,” said Dr. Gary Kirk, the medical officer of health at the Windsor-Essex County Health Unit. “We assume no risk of transmission. Zika has not been found [with these mosquitoes].”
“We feel good about saying there is no risk,” he said.
There has been one travel-related case of Zika in Windsor-Essex, Kirk told reporters, but he did not elaborate. He said the risk of infection for Windsor-Essex residents is confined to travellers heading to areas where Zika is prevelant.
Though these particular mosquitoes tested negative for Zika, the insects are a known carrier of the disease. The species is uncommon in Canada, but is an invasive species that has been reported in the Niagara Region.
It’s believed the four mosquitoes were brought to Ontario by a cross-border traveller from the United States, Kirk said. These are the only reported cases of this type of mosquito found in Ontario this year.
The Asian tiger mosquito is found in the southern United States, but it generally does not reach as far as Michigan, according to the U.S. Centers for Disease Control.
An Asian tiger mosquito was found once before in Windsor, in 2012, which had a summer similar to this year. That weather could have been responsible for allowing the Asian tiger mosquito to survive.
The mosquitoes found in Windsor are a relative of the Aedes aegypti, the mosquito responsible for transmitting Zika in humans in the Caribbean and Florida.
Kirk said the Aedes aegypti has not been found in Windsor.