Due to its vector mosquito's inability to survive in cold climate, the Zika virus used to be endemic only to tropical regions.

However, the mosquito-borne infection has spread to countries such as the United States, South Africa, and more recently, Canada, but mostly it's because residents travel to countries that are infected.

Public health officials in Canada have confirmed on Thursday three new cases of Zika virus in Saskatchewan, Ontario, and Alberta.

Details about the patients' age and gender were not disclosed, but health officials in Ontario revealed in a statement that one of the patients had tested positive for Zika after traveling to Colombia.

Ontario's Ministry of Health and Long-Term Care said that the patient is not pregnant, although they did not say if the patient was a woman or a man.

Dr. David Williams, Ontario's chief medical officer of health, said that since the beginning of the Zika outbreak, the province has taken steps to make sure that their health system and partners are prepared in case a returning traveler becomes suspected of having the virus.

The ministry urges anyone who had traveled to any of the affected countries to talk to their health-care provider who can advise them should they need testing.

"Ensuring that Ontarians are fully informed about emerging and infectious diseases such as Zika virus is a priority," said Williams.

Health officials said the risk to Ontario residents are "very low", especially because the mosquitoes that carry Zika are not established in Canada and cannot survive in the country's cold climate.

With that, some scientists are testing whether mosquitoes that are native to the country can be carriers of Zika and whether they can potentially transmit the disease.

Meanwhile, Alberta's health department had already identified at least four lab-confirmed cases in the province. There was one case in 2013, and three in 2016, officials said.

In January this year, the British Columbia Centre for Disease Control confirmed two Zika cases in the province. One patient had been to El Salvador, while the other had traveled to Colombia.

Most people infected with Zika virus do not exhibit symptoms. Those who do get sick typically have rash, a minor fever, joint pain and/or eye problems such as red eyes.

A small number of Zika virus cases have been confirmed in the past among persons in Quebec, Alberta, and British Columbia who have returned home infected, officials said.

Zika virus has been linked to cases of microcephaly in Brazil, and a new report by researchers in Yale University found that the virus might also cause stillbirths.

The stillborn baby had signs of severe swelling of brain tissues, as well as the birth defect that cause parts of the cerebral hemispheres to be missing, the university's Public Health said.

However, the study is an isolated case, so further investigation needs to be done, experts said.