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Wednesday, August 16, 2017 | 11:30 a.m. | Windsor-Essex County

Photo of a blood-engorged female Aedes albopictus mosquito feeding on a human host. Credit: CDC/ James Gathany

Two adult Aedes albopictus mosquitoes have been found in a single enhanced mosquito trap, a BG Sentinel 2 trap. After last year’s discovery of the Aedes species in the area, the Health Unit worked closely with the Ministry of Health and Long-Term Care, Public Health Ontario, and the Public Health Agency of Canada to enhance this year’s local mosquito surveillance program to monitor for the presence of the Aedes species.

Aedes albopictus has been identified across the United States, including Vermont, New York, New Hampshire and Massachusetts. Although this species of mosquito, also known as the Asian tiger mosquito, is capable of transmitting viruses including Zika, it is not the species that is responsible for the majority of human cases of Zika virus infection in the Caribbean, South America and Florida. When analyzed in the laboratory, the two Aedes albopictus mosquitoes found both tested negative for Zika virus and West Nile virus. Last year, all 17 trapped Aedes albopictus mosquitoes also tested negative for Zika virus and West Nile virus.

Although it is unknown exactly how the mosquito arrived in Ontario, we suspect that the adult mosquitoes were transported from the U.S. in shipping containers or other cross-border vehicle traffic. This year’s discovery may be a new Aedes albopictus mosquito colony or it may be last year’s colony that has been able to survive in Windsor because of the mild winter and the current hot temperatures.

“Keeping our community informed about infectious diseases and the local mosquito surveillance programs is a key role of public health. The discovery of the Asian tiger mosquitoes again this year is an important reminder to everyone that we should continue to protect ourselves and our families from mosquito bites,” said Dr. Ahmed, Acting Medical Officer of Health, Windsor-Essex County Health Unit.

Aedes albopictus feed on humans but they also feed on a variety of animals, which makes it less likely for them to be the primary mosquito for spreading the Zika virus. For Zika virus transmission to occur, the Aedes albopictus mosquito would need to feed on an infected person then feed upon another susceptible person. The greatest risk to contracting Zika virus continues to be centred on those who have travelled to Zika-risk areas (such as South America, the Caribbean and Florida) or who are or have been in sexual contact with these travellers.

Unlike many Ontario mosquitoes, Aedes albopictus mosquitoes are aggressive daytime biters, with peaks in activity in the early morning and late afternoon. These mosquitoes do not breed in ponds, puddles or marshes. They typically lay eggs in and near standing water in items such as buckets, bowls, animal dishes, flower pots and vases. It is important to change water regularly, especially in pet dishes and water in bird baths.

While there is no change in risk for Zika virus in our community, it is still important to protect yourself and your family from mosquito bites. Until the first freeze hits, we are still at risk for West Nile virus and need to continue protecting ourselves. Individuals can do so in several ways:

Use insect repellents that contain DEET, Icaridin or other approved ingredients on clothing as well as exposed skin. Always read and follow label directions.

Wear long-sleeved shirts, long pants, and a hat when outdoors. Light-coloured clothing is best as mosquitoes tend to be attracted to dark colours.

Make sure that door and window screens fit securely and are free of holes.

The Windsor-Essex County Health Unit is conducting an additional investigation where the two adult Aedes albopictus mosquitoes were found. Based on the evidence gathered, the Health Unit will determine the best course of action moving forward and will inform the community on those next steps.

Media Contact

Communications Department
Windsor-Essex County Health Unit
519-258-2146 ext. 6397 (NEWS)
news@wechu.org