Mosquito responsible for majority of Zika infections found in Canada for first time

Staff from the Windsor-Essex County Health Unit recently trapped the insect, a discovery health officials believe signals the species is becoming established in southern Ontario.

Discovery points to species becoming established in Ontario

This 2006 photograph shows a female Aedes aegypti mosquito while she was in the process of acquiring a blood meal. (Frank Hadley Collins/Centers for Disease Control and Prevention)

An adult Aedes aegypti mosquito, the species responsible for the majority of human Zika virus cases, has been found in Canada for the first time.

Staff from the Windsor-Essex County Health Unit recently found the insect in a trap, a discovery health officials believe signals the species is becoming established in southern Ontario.

"It was just in such good shape, we are absolutely 100 per cent sure of what species it is," said Fiona Hunter, from Brock University, who heads up the lab that tested Windsor's mosquitoes. "It didn't just blow in from the (United) States."

Last week, the health unit revealed two Aedes albopictus mosquitoes, also known as the Asian tiger mosquito, had also been found in the area.

"Once they establish themselves here it would be more difficult to control and maybe we'll see some diseases we haven't seen before," said Dr. Wajid Ahmed, the region's acting medical officer of health, at the time.

Having the Asian tiger show up in Canada was a bit of a surprise, considering it wasn't expected to migrate north for at least another decade, Hunter explained. But the odds of it arriving is still higher than the latest species. 

"The Asian tiger mosquito is known to exist farther north in the (United) States ... but Aedes aegypti is supposed to be sub-tropical, so what on earth is it doing here?"

All Aedes mosquitoes found in Windsor-Essex so far have tested negative for both the Zika and West Nile virus. Given there are no active cases of the diseases, there's less cause for alarm, according to Hunter. 

"I think it's alarming — for the country — that our climate is changing," she said. "In the last decade we've added another 10 mosquito species to our endemic list ... so we know something is going on."