While there have been four confirmed cases of the Zika virus in Canada, the government says it’s still only travellers who are at risk.

“The mosquitoes that transmit the virus to humans are thought not to be established in Canada, so a local epidemic or endemic transmission is very unlikely,” according to a rapid risk assessment last updated on Jan. 28.

The Public Health Agency of Canada now lists 26 countries on its "travel health notices" list, urging travellers to "practice special precautions" when in areas affected by the Zika virus. That list has grown from 10 countries earlier in the year and now covers much of South America.

As of Feb. 3, the U.S. Centers for Disease Control lists 30 areas where active transmission of the virus is taking place.