A B.C. resident who recently travelled to El Salvador contracted a virus spread through mosquito bites, the Public Health Agency of Canada says.

The Zika illness is caused by the bite of an infected Aedes mosquito, usually causing mild fever, rash, conjunctivitis (pink eye), and muscle pain, the Pan American Health Organization says. 

Mosquitoes known to transmit the virus to humans are not present in Canada.  The same type of tropical mosquito also transmits dengue and chikungunya. 

Symptoms of infection are usually mild and last for two to seven days. Headache and rash, along with joint and muscle pain, can also occur. 

About one in four people infected with the virus are believed to develop symptoms, a spokeswoman for the Public Health Agency of Canada said Monday.  

"The risk to Canadians is low," the agency's notice says.

And there have been no reported cases of the virus in Canada.

"Canadian travellers visiting affected areas, particularly pregnant women, should help protect themselves against Zika virus by taking individual protective measures to prevent mosquito bites, including using insect repellent, protective clothing, mosquito nets, screened doors and windows."

There is no preventive vaccine or specific treatment for Zika virus, which focuses on relieving pain, fever, and any other symptoms. 

South American cases

The virus was isolated for the first time in 1947 in the Zika forest in Uganda, the Pan American Health Organization said. Since then, it has circulated mainly in Africa, with small and sporadic outbreaks in Asia.

Last year, the virus was confirmed in Brazil, Panama, Venezuela, El Salvador, Mexico, Suriname, the Dominican Republic, Colombia, Guatemala and Paraguay, according to public health officials.

Trudie Lang, professor of Global Health Research at Oxford University, called Zika a cause for concern for investigators. 

"It's definitely becoming an issue, but there is so little research that we just don't know the size of the potential 
threat," Lang she told Reuters.

Health officials in Brazil also suspect a link between Zika virus and infants born with an abnormally small head and microcephaly, an underdeveloped brain that can limit a child's mental and physical abilities. 

The Brazilian investigation points to an average 20-fold increase in incidence of microcephaly among newborns born in areas where Zika virus circulates. 

"Although there is mounting evidence to warrant concern, the investigation is ongoing to confirm whether Zika virus may be the cause of these microcephaly cases," the Canadian public health agency said. 

Reducing the breeding of mosquitoes is another prevention strategy, the World Health Organization says.  

With files from Reuters