The Northwestern Health Unit reported yesterday that a dead crow collected in Kenora has been confirmed positive for West Nile virus. This is the first positive case of an infected bird in the catchment area of the health unit this year.
“This came as no surprise whatsoever,” stated Al Mathers, environmental health officer for the NHU. “This is about what we had this time last year,” he added, noting the first positive crow was found last year on July 25.
The crow that most recently tested positive was picked up on July 26. A total of two crows were confirmed positive last summer in the City of Kenora
A total of five dead crows in Rainy River District tested positive for the West Nile virus last summer—three in Fort Frances, one in Atikokan, and the other north of Devlin.
In 2002, no birds collected in Rainy River District were found to be positive. But three did from the Kenora District—one each from Kenora, Dryden, and Sioux Lookout.
Also that year, two horses—one in Rainy River and the other in Devlin—were confirmed positive for the West Nile virus. A third horse from Littlefork, Mn. died due to it in 2002.
No human cases or equine cases of West Nile virus have been identified here so far said Mathers.
West Nile virus is spread to humans by the bite of an infected mosquito. Mosquitoes become infected by biting an infected bird.
Crows and ravens are particularly susceptible to the virus and thus serve as an effective early-warning indicator. However, the Kenora-Rainy River district is not considered to be a high-risk area for the disease.
“We are in an area of relatively low-risk,” assured Mathers. “And with the nights becoming cooler, the season is coming to an end soon anyway.”
Mathers still recommended people observe the usual precautions—wear long-sleeved garments, avoid exposure during the peak hours of mosquito activity, remove sources of standing water, and use repellents containing DEET.
Since May 25, the health unit has been accepting dead crows and ravens that look like they may have succumbed to the virus and sending them away to the University of Guelph for testing.
The health unit will continue to collect reports of dead bird sightings, as well as submit crows for testing when considered appropriate, until the mosquito season definitely is over.
Updates on further positive test results will be provided when, and if, they occur.
The risk of becoming seriously ill as a result of an infection with West Nile virus is low.
In fact, most people who become infected experience no symptoms or have a very mild illness, with fever, headache, muscle weakness, or body aches, Mathers noted.
“I would assume if you get bitten by an infected mosquito, it’s only a small percentage of people who will exhibit symptoms,” he remarked.
“In fact, there is even some evidence from pediatricians that exposure to the virus may provide a level of immunity,” he added.
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, as well as altered levels of consciousness and mental states.
Though the risk of infection is low, the risk still exists, and precautionary measures should be taken to avoid unprotected exposure to mosquitoes, and to eliminate any potential breeding sites for mosquitoes.
Recommended measures include:
•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.
Mathers pointed out, the NHU will not be recommending to municipalities that they pursue a spraying campaign, as has been done in other areas.
“I don’t like chemical applications,” Mathers stressed. “In fact, it (spraying) could do more harm than good.”
The mosquito surveillance program conducted by the health unit has been active since early July, but to date, no West Nile virus-positive mosquitoes have been identified.
Fort Frances Times
Local News from Across the Rainy River District
