A human case of West Nile Virus (WNV) was reported to Grey Bruce Health Unit last week. In addition, a second positive equine case of WNV was reported and the first local positive mosquito pool was identified.
This trend mirrors patterns being observed in health units across Ontario; WNV activity tends to increase to peak levels in the late summer and early fall. At the time of this release 370 positive mosquito pools had been identified throughout the province and 37 human cases reported.
WNV is transmitted through the bite of an infected mosquito. Symptoms usually develop 2 to 14 days after receiving a bite from an infected mosquito. Approximately 80% of those infected with WNV do not show any symptoms. Of the 20% that do show symptoms, most experience mild illness with symptoms such as fever, headache, body aches, fatigue, skin rash and occasionally, vomiting and nausea. Less than 1% of those infected with WNV experience severe illness involving the central nervous system.
The risk of exposure to WNV around the home can be reduced by eliminating mosquito breeding sites, including standing water in places such as bird baths, eavestroughs, flower pots and discarded tires; by wearing protective clothing; always using mosquito repellent when outdoors at dawn and dusk; and by preventing mosquito entry into the home.