January 2021 Board of Health Meeting - Mosquito Surveillance and Control Program 2020 Information Report

Meeting Document Type
Information Report
Mosquito Surveillance and Control Program 2020


January 21, 2021


Mosquito Surveillance and Control Program 2020


The Environmental Health Department conducts annual monitoring and testing of mosquito populations in Windsor and Essex County (WEC) as part of the WECHU’s Zoonotic and Vector-borne Diseases Program.

Mosquito Surveillance and Testing

Adult mosquito surveillance runs from May to early October every year and may extend depending on the weather and temperatures. Species-specific traps are deployed in various locations throughout WEC to capture mosquitoes for testing and identification to determine the presence of West Nile, Eastern Equine Encephalitis (EEE) Virus, and Zika Virus in our community. Invasive mosquito species Aedes aegypti (Yellow Fever Mosquito) and Aedes albopictus (Asian Tiger Mosquito) are also monitored each year through our Enhanced Mosquito Surveillance Program. These species are known carriers of diseases such as Zika, Malaria, Dengue, and Chikungunya. The WECHU received a federal grant from the Public Health Agency of Canada’s Infectious Disease and Climate Change Program (August 2019 to March 2022)  to study the effects of climate change and mosquito populations in our local communities. For the 2020 season, an additional 14 traps were placed in Leamington to monitor mosquito populations as part of this grant.

During this year’s season:

  • Total number of mosquitoes trapped: 205,569
  • Total number of pools tested: 2,052
  • Number of positive pools for West Nile virus : 30
  • Number of positive pools for Zika virus: 0
  • Number of positive pools for EEE virus: 0

Mosquito Control

The mosquito control program involves applying larvicide to catch basins and standing water sites such as ditches and lagoons that hold water. All municipalities in WEC have standing water by-laws in place. In 2020, over 135,000 treatments of larvicide were applied to roadside catch basins and standing water sites.

Human Cases

The WECHU follows up on all human cases of West Nile Virus. Cases are investigated to assess if additional mosquito control activities are required. In 2020, there were two confirmed and one probable case of WNV in WEC. To date, there have been no human cases of Zika Virus identified in WEC.

Education and Awareness Raising Activities

Fight the Bite public awareness campaign was launched in June and included key messages that focused on preventing mosquito bites, removal of standing water and the cause and symptoms of West Nile Virus. These messages were communicated through the WECHU website, radio, billboard and bus shelter ads, social media, and print materials.


All activities, including monitoring and testing mosquitoes and education regarding personal protection from mosquito bites and removing standing water, will continue in 2021.  Targeted promotion and messaging will be used to reach priority populations and inform the public of hot spots identified through previous monitoring efforts.