Ontario has its first confirmed case of the mosquito-borne Zika virus as the winter vacation season to warmer climes hits high gear.
The patient, a woman who is not pregnant and whose identity and condition are not being released for privacy reasons, had recently returned from a trip to Colombia.
“On Tuesday, Public Health Ontario received positive test results” for the patient, said Dr. David Williams, the province’s chief medical officer of health.
“The risk to Ontarians remains very low, as the mosquitoes known to transmit the virus are not established in Canada and not well suited to our climate,” Williams said in a statement late Friday afternoon.
Zika cases have soared in Caribbean countries, Mexico, South and Central America since the first instances were revealed in Brazil last May.
As many as 4,400 babies in Brazil have been born with microcephaly, in which babies have abnormally small heads and brains, to women who may have been bitten by mosquitoes carrying the virus.
On Feb.1, the World Health Organization a global health emergency over an outbreak of birth defects and neurological disorders linked to the fast-spreading Zika epidemic, in a move that reflects the extraordinary circumstances surrounding a virus that causes no symptoms in the vast majority of cases.
The Public Health Agency of Canada issued its first travel notice in mid-January following other confirmed cases of Canadians returning from Central and South America with Zika.
Although the Zika virus is not transmitted by the type of mosquitoes in Canada because of its cold climate, Williams and Health Minister Eric Hoskins warned last month that there is “ongoing risk” to Ontarians travelling to affected areas in tropical parts of the Americas and the Caribbean.
They urged travellers to “take protective measures to prevent mosquito bites” and said women who are pregnant or thinking about becoming pregnant should consider postponing trips to Zika-prone countries.
The news about the Ontario case comes as insect scientists at Brock University in St. Catharines have received a shipment of the virus to test whether mosquitoes native to Canada could become infected with the pathogen and potentially transmit it to humans.
Brock is the only university in the country with a high-level containment lab that includes and insectary, allowing the testing to be conducted safely.
First discovered in Uganda in 1947, Zika is spread mainly by the Aedes aegypti, a mosquito that bites mostly in the daytime and is found in every country in the Americas except Canada and continental Chile.
Until lately, experts thought Zika caused only mild symptoms, including fever, joint pain and rashes with the majority of infected people showing no symptoms at all.
Williams urged any Ontarians who have been to Zika-prone areas and are exhibiting similar symptoms to be checked out by a doctor.
But the virus has now spread very rapidly to 24 countries and territorites in less than a year and has been associated with an alarming surge in neurological disorders such as microcephaly.
The virus has also been linked to Guillain-Barré syndrome, a potentially fatal autoimmune disorder that can cause temporary paralysis, with increased numbers of cases being reported in Brazil, El Salvador, and French Polynesia, which experienced a Zika outbreak in 2013 and 2014.
However, it could take months or years to prove whether Zika is directly causing either Guillain-Barré or microcephaly.