Province spots first West Nile mosquitoes of season

Phil Curry, an entomologist and consultant with the Ministry of Health, told reporters in Regina that the first Culex tarsalis mosquitoes have been spotted in traps around Saskatchewan.

“We are detecting low numbers of that species, particularly in the southern part of the province,” he said.

Culex tarsalis is the species of mosquito that carries the West Nile virus.

Curry explained that the bugs pick the virus up from birds and then transmit it to other mammals.

The many mosquito traps the province has around Saskatchewan can catch more than 100 mosquitoes in a night. Lisa Schick/980 CJME

He said none of the mosquitoes found so far have been carrying the disease, but he expected that to change over the next few weeks as Culex tarsalis numbers begin their seasonal rise.

“So it reaches a peak usually around the end of July, even as other mosquitoes might start to peter out,” he said.

West Nile doesn’t present any symptoms in about 80 per cent of cases where people are infected, according to the World Health Organization (WHO).

About 20 per cent of those infected develop symptoms including fever, headache, tiredness, body aches, nausea and vomiting.

In the most serious cases, West Nile virus can cause a form of potentially fatal meningitis.

The WHO estimates about 1 in 150 people infected with West Nile develop a more serious form of the disease.

The virus typically takes between three days and two weeks to incubate. With no known vaccine or cure for humans, Curry said preventing mosquito bites is the best defence.

“Wear repellents, cover up. Particularly in the evening or at night — that’s when all mosquitoes are most active.”

Saskatchewan’s last major West Nile outbreak occurred in 2007 when just over 70 serious cases were reported. Since then, the province has seen an average of one case per year.

—With files from 980 CJME’s Lisa Schick