While the Northwestern Health Unit reported Monday that three dead crows from Fort Frances have tested positive for West Nile virus, bringing the total for Rainy River District to five this summer, that very well may be the last time the disease shows up in 2003.
“Talking to folks from southern Ontario, this is the time of year we should expect to get positive results, if at all, so it’s not really surprising,” said Al Mathers, environmental health officer with the Northwestern Health Unit.
“There is a theoretical risk of further infections by mosquitoes until the first heavy frost. But the way the weather’s been lately, I don’t see too many of the little guys around,” he added.
Mathers said any mosquitoes spotted recently are not likely looking for “blood meal” but instead simply are interested in finding a place to go into stasis for the winter.
Mosquito activity usually ceases once the temperature drops below 12 C for an extended period of time, he noted.
The health unit received word of the positive test results on the three crows from the Canadian Co-Operative Wildlife Health Centre in Guelph on Friday, but didn’t release this information until Monday afternoon.
As a consequence of these positive findings, the health unit has been asked to suspend its bird collection program within a 20-km radius of the sites where the positive birds were located, which all were near residences in town, public health inspector Brian Norris said Monday.
This means residents of Fort Frances should refrain from reporting to the health unit any more dead crows, ravens, and jays they may find until the next bird surveillance season begins next May.
These are not the first positive cases of infected birds found in Rainy River District. Two other crows—one in Atikokan and the other north of Devlin—were confirmed positive in August.
These five bring the total for the Kenora-Rainy River districts to seven as two were confirmed positive this summer in the City of Kenora.
No birds collected in Rainy River District last year were found to be positive. But three from the Kenora District—one each from Kenora, Dryden, and Sioux Lookout—did.
Besides the crows, two horses—one in Rainy River and the other in Devlin—were confirmed positive for the West Nile virus last September and October, respectively, while a third horse from Littlefork, Mn. died due to it last August.
There have been no human cases identified in the district so far.
West Nile virus is spread to humans by the bite of an infected mosquito. Mosquitoes become infected by biting an infected bird. The virus is not spread by person-to-person contact.
It also cannot be spread directly from bird to human.
The risk of becoming seriously ill as a result of an infection with West Nile virus is low, and most people who become infected experience no symptoms or have very mild illness, with fever, headache, muscle weakness, or body aches.
“But as long as there’s mosquitoes, we recommend that people follow the precautions we’ve set out,” said Norris.
According to the health unit, the public can lessen this risk by:
•removing any standing water on their property;
•avoid being outside between dusk and dawn, if possible;
•turning over wading pools when not in use;
•ensuring eavestroughs are draining properly;
•replacing damaged screening on windows and doors;
•wearing light-coloured clothing when going outside;
•wearing long-sleeved shirts and pants between dusk and dawn; and
•using a personal insect repellent containing DEET, following the manufacturer’s label instructions carefully, especially as it relates to children.
Those at increased risk of severe illness are individuals over age 50 and people with weakened immune systems.
Symptoms of West Nile virus encephalitis (the rare, serious form of the disease) include severe headache, stiff neck, nausea and vomiting, and altered levels of consciousness and mental states.
In related news, Mathers said the provincial campaign to monitor West Nile virus by collecting mosquito samples, which began back in early August, didn’t quite go as expected.
“It was difficult to do. We probably should have started earlier,” he noted. “We didn’t get too many collected. The weather wasn’t right, and then it got cold at night.”
The health unit was expected to, if at all possible, send in at least two mosquitos per week during the 10-week project.
To do the campaign, the health unit had received five mosquito traps, which are comprised of a cylinder cooler, dry ice, a black light, fan, netting, and a small plastic bucket in which to collect the specimens.
With these, the bugs were attracted by the carbon dioxide from the dry ice and black light. When they got close enough, they’re sucked into the netting by the fan.
The few specimens that were collected here were sent in small cups to Brock University in St. Catharines for testing. Mathers noted all of these came back negative for West Nile virus.
But one successful aspect of the project was that all of the samples collected were specimens of the main virus-carrying mosquito species, the Culex (or common house mosquito), which breeds in very shallow water and has a short range.
It’s most commonly found in urban areas.
Because the greatest number of West Nile-positive specimens so far have come from Fort Frances this summer, Mathers noted the traps may be set up here next year instead of in Kenora.
(Fort Frances Times)
Fort Frances Times
Local News from Across the Rainy River District
