Four Canadians test positive for Zika

Four Canadians have been confirmed as being infected with the Zika virus, the country's chief public health officer said.

Dr. Gregory Taylor on Friday said two cases were reported from the western Canadian province of British Columbia, one from Alberta and another from Quebec, all have recently returned from Zika virus-active areas such as Central and South America and the Caribbean, Xinhua reported.

The Aedes aegypti mosquitoes that transmit the virus are not present in Canada because they are not adaptable to the country's cold climate, Taylor said. "So the risk of Zika virus infection in Canada is considered very low."

Only one of the four cases is likely to develop symptoms, such as low-grade fever, joint pain, red eyes, rash, muscle pain, physical weakness, lethargy and headaches, which may last from two to seven days.

Taylor explained that while mosquitoes are the main source of transmission, the virus could be passed from mother to child.

According to a Canadian Public Health Agency notice, there is concern that an increase in the incidence of microcephaly, or abnormally small heads among newborns reported in Brazil last year may be linked to the Zika virus.

Zika virus infection may also go unrecognised or be misdiagnosed as dengue, chikungunya or other viral infections causing fever and rash, according to the Public Health Agency.

There is no vaccine for the virus at the present. A group of Canadian and the US scientists are working on a potential vaccine that is reportedly ready for testing on humans. The first clinical trial is expected to start this summer.