Health unit undertakes West Nile virus surveillance program

The Windsor-essex County Health Unit has once again started to monitor the region’s mosquito population.

The annual program includes putting larvicide in catch basins, standing water sites and lagoons to disrupt mosquito breeding, educating residents on self-protection, conducting adult mosquito surveillance, and investigating positive human cases of West Nile virus in the community.

“The risk of contracting West Nile virus through the bite of an infected mosquito still persists,” said medical officer of health Dr. Wajid Ahmed on Tuesday.

“Each year, we have to prepare and assume that mosquitoes are carrying the West Nile virus. By taking simple precautions, residents can reduce the risk of being bitten by mosquitoes.”

The program involves setting up mosquito traps throughout Windsor

and Essex County to capture the bloodsuckers. Once caught, they are sent to a lab where they are identified and tested to determine the presence of West Nile virus and Eastern equine encephalitis in the area.

In 2016, multiple tropical species of mosquitoes capable of carrying the Zika virus, dengue fever, and chikungunya were captured in Windsor. Those species of mosquitoes are not common to Canada.

The health unit responded by developing an enhanced mosquito surveillance program, which included placing additional traps throughout Windsor. In 2019, program expansion saw more traps in the county following the identification of a tropical mosquito species in Kingsville.

“This year, we will deploy additional traps in other parts of the county like Leamington and Lakeshore to monitor these tropical mosquitoes, though the risk of Zika virus remains extremely low in our region,” Ahmed said.

Last year, 979 mosquito pools were tested and 27 of those pools were positive for West Nile virus. The region saw one human case of the virus.

Ahmed said there is no evidence to indicate mosquitoes can transmit COVID-19.

The health began conducting its West Nile surveillance program in 2003.

To stay protected from mosquito bites, the health unit advises residents to remove any standing water from properties.

That includes bird baths, buckets, old tires, pet water dishes, and gutters. Mosquitoes can breed in water-filled containers as small as a bottle cap.

Wearing long-sleeved shirts, long pants, and a hat when outdoors can also prevent bites. Mosquitoes tend to be attracted to dark colours, so light-coloured clothing is best.

The health unit also recommends using insect repellents that contain DEET, Icaridin, or other approved ingredients on clothing as well as exposed skin. Always read and follow label directions.

Finally, make sure that door and window screens fit securely and are free of holes. Call 311 or local bylaw enforcement to report standing water observed in the community.

We have to prepare and assume that mosquitoes are carrying the West Nile virus.