Mosquitoes that could carry Zika found in Windsor, Ont.

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.

There has been one travel-related case of Zika in Windsor-Essex. Dr. Gary Kirk, the medical officer of health for the Windsor-Essex County Health Unit said the risk of infection for Windsor-Essex residents is confined to travellers heading to areas where Zika is prevalant.

When CBC followed up for more information, a spokesperson with the health unit would not release details on the individual citing privacy concerns. They only said the person travelled “at the end of the summer.” 

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. 

  • Canadian mosquito spread of Zika untested
  • 20 Canadians, including pregnant woman, infected by Zika in 20 countries
  • Zika virus: What you need to know and how to protect yourself

“I want to go out of my way to say [the mosquitoes] weren’t infected with Zika virus,” Kirk said. “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. 

Mosquitos tested negative for Zika 

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.