Toronto Public Health (TPH) has reported the city’s first probable human case of West Nile virus this year.
In a news release on Friday, the public health unit said the case is in an adult resident. West Nile Virus is an infection that is transmitted to people through the bite of an infected mosquito.
TPH said in an email that it received a report about the case on Friday but did not diclose any other information about the person.
“West Nile Virus is a disease of public health significance and is reportable to the Medical Officer of Health,” TPH said.
TPH said it conducts “mosquito surveillance” from mid-June until mid-September every year. Once a week, it sets 22 mosquito traps across the city to collect mosquitos that it tests for the virus.
“Given the vast range of mosquitoes throughout the GTA, it is difficult to determine the exact location of where a resident could have contracted the virus,” TPH said in the email.
Nearly 80% of people with virus don’t get sick
The public health units says it is difficult to predict how many people may be infected in any given year because of how many factors affect mosquito activity.
Close to 80 per cent of people infected with West Nile Virus do not get sick and do not seek out medical attention, the public health unit said, and the cases go undetected.
Last year, the city’s first probable case of the virus was reported on Aug. 4.
Symptoms, which usually begin to show two to 14 days after a person has been bitten by an infected mosquito, may include fever, headache, nausea, vomiting, body aches, skin rash and swollen lymph glands.
Older people or people with compromised immune systems are at higher risk of severe illness, according to the public health agency.
Toronto Public Health said residents can protect themselves from the virus in the following ways:
- Wearing light-coloured, long-sleeved shirts and pants when outdoors.
- Applying an insect repellent approved by Health Canada and following the manufacturer’s instructions.
- Taking extra care during peak mosquito-biting time, which is dusk and dawn.
- Removing standing water from property where mosquitos can breed.
- Ensuring screens are tight-fitting on windows and doors.
Anyone who is concerned about any symptoms should contact their health care provider, TPH says.