Is there a risk of chikungunya transmission in Canada?

An outbreak of chikungunya virus infection is currently underway in the Caribbean, Central America and South America, and autochthonous (local or indigenous) transmission has occurred in the southeastern United States. The mosquito species known to transmit chikungunya-Aedes aegypti and Aedes albopictus-are not known to reside in Canada at this time. But how comfortable can we be that this situation will continue? Here we explore four key conditions that must be met for transmission of chikungunya within Canada. We conclude that not all of these conditions have been met and the risk of chikungunya transmission in most of Canada appears to be very low at present. The risk is slightly higher in warmer areas, such as southern British Columbia and isolated locations in south central and southeastern Canada. However, there are significant gaps in our knowledge and ongoing risk assessment, research and surveillance for vectors of chikungunya are indicated.