A blue jay found dead early this month near Hanover had West Nile virus.
It’s Ontario’s first confirmed case of the mosquito-borne disease this season, Grey-Bruce medical officer Hazel Lynn said Wednesday.
The bird was found May 7, an unusually early case. Last year’s first local confirmation wasn’t until July 7.
No people or mosquitoes have tested positive for West Nile in the area this season or last and it’s unlikely the jay contracted the disease from a local mosquito bite, Lynn said.
With heavy rainfall this spring, there are plenty of “swampy mosquitoes” around already. They can transmit the disease, but the culex variety, one of 56 types in Ontario, is the one most associated with the West Nile disease.
It breeds in warm, shallow pools of water.
“I don’t think this bird could have caught it here,” Lynn said.
“The actual mosquitoes that tend to amplify West Nile are the ones that like warm little pots of water around your house.”
So it’s a good idea to get rid of any shallow pools you find.
“If we can avoid letting the culex breed, then we can eliminate the problem of West Nile virus,” Lynn said.
Those shallow pools have now been well flushed by the heavy rains and won’t produce another crop of culex for at least 14 days, and more likely 28 days before any West Nile carriers are likely.
Just to make sure the disease isn’t in the local mosquito population, health unit officials plan intensive trapping and testing of mosquitoes in the relatively uninhabited area southeast of Hanover where two blue jays were found dead. The other tested negative for West Nile.
The Grey-Bruce Health Unit is one of several in Ontario also testing mosquitoes this year for Eastern equine encephalitis, considered among the most serious of mosquito-borne diseases which can be contracted by humans.
There were several cases found in animals in Grey-Bruce last year, but none in people, Lynn said.
Last year, four birds tested positive for West Nile among hundreds Grey-Bruce residents sent in for testing from mostly southern Grey-Bruce.
None of the mosquitoes sent to St. Catharines from Grey-Bruce for analysis last year tested positive, Lynn said.
Two humans found with the disease spent time in Grey-Bruce during the incubation period, but were almost certainly bitten elsewhere, she said.
Most people who become infected through a mosquito bite experience mild symptoms such as fever or headaches. In a small number of cases severe symptoms include inflammation of the brain.
On rare occasions, the disease can cause death, the health unit said in a news release.
Most people don’t take warnings about the disease seriously, Lynn said.
According to health unit surveys last year, almost everybody was well aware of West Nile, but few changed because of it.
“Everybody knew about it. There was nobody that hadn’t heard about. The number of people that actually changed their behaviours and wore long sleeves and used DEET and stayed out of mosquito areas was minuscule, a few per cent,” Lynn said. “Although they all knew about it, they just went about their business.”
The recent positive test results confirm that West Nile is here to stay, Lynn said.
“Obviously West Nile virus is going to be around with us. We kind of hoped it would go away. It’s not going to. I don’t like getting a bird this early. It certainly assures us this disease is around and will be around.”
~Owen Sound Sun Times~