The Windsor Essex County Health Unit says four mosquitos known to transmit Zika have been found in a Windsor-Essex trap.

They all tested negative for Zika and the health unit says there are no cases of locally transmitted Zika.

One person to date has had Zika in Windsor-Essex. The health unit says they got the virus from travelling.

Dr. Gary Kirk, medical officer of health and CEO of the Windsor-Essex County Health Unit, says the Aedes albopictus mosquitoes were found in a local mosquito trap during routine monitoring and surveillance for West Nile virus.

“Ensuring that our community stays informed about infectious diseases and the local mosquito surveillance program is a key role of public health to the residents of Windsor-Essex County,” says Kirk.

“The discovery of the Asian tiger mosquitoes in a local trap is an important reminder to everyone that we should continue to protect ourselves and our families from mosquito bites.”

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, a total of four Aedes albopictus mosquitoes, found over two consecutive weeks were tested for Zika virus and all tested negative, says Kirk.

This particular mosquito has been identified in this area previously, when a single Aedes albopictus mosquito was identified in 2012.

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.

Given that this is a tropical mosquito, the extremely hot temperatures this past summer allowed for the species to exist in Windsor.
Kirk says our relatively cold winters will usually kill them off and prevent them from becoming established.
The Aedes albopictus feeds on humans but they also feed on animals, which makes it less likely for them to spread the 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 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 potters and vases.

Kirk says it is important to change water regularly, especially in pet dishes and water in bird baths.