Canada's health agency Wednesday called on pregnant women who visited the Miami area in Florida of United States on or after June 15 to take medical precaution measures against the Zika virus.

The Public Health Agency's call came after the U.S. Centre for Disease Control and Prevention said mosquitoes have apparently started spreading Zika on the U.S. mainland and the transmissions are limited to the Miami-Dade county of Florida.

Some four million Canadians visit Florida every year, the agency said any pregnant women who visited the area on or after June 15 should see their health care providers for testing.

The women who have been to the region should wait two months before trying to become pregnant. And because the virus can linger in sperm, men should wait six months before attempting to impregnate a partner, said the agency.

Some 80 percent of those infected with Zika had symptoms. However, Zika infection during pregnancy can cause a serious birth defect of the brain called microcephaly and other severe foetal birth defects.

The agency also advised pregnant women and those planning a pregnancy to avoid travel to the area in south Florida and other countries with reported mosquito-born Zika virus.

Up to date, there have been no reported cases of people infected by mosquitoes in Canada because mosquitoes known to transmit the virus are not reportedly established in Canada and are not well suited to the Canadian climate.