Toronto is finally starting to warm up again and people are more than ready to shed their winter blues and get back out in the sun. It was a long cold winter this year for the city and, let’s be honest, a rainy and disappointing spring. However, with summer fast approaching, public health officials are cautioning residents to protect themselves and their families against the West Nile virus in Toronto.
According to Toronto Public Health (TPH) the West Nile virus is a potentially serious illness that is transmitted to humans through the bite of an infected mosquito. Thankfully, the chances of infection in Toronto are low. However, TPH emphasized that there's still a risk, and mosquitoes have tested positive for the virus in recent years.
TPH representative Dr. Christine Navarro tells Narcity that there were a total of “40 positive mosquito tests for West Nile virus” in Toronto last year.
According to Dr. Navarro, the number of positive mosquito tests varies from year to year, mostly due to temperature. Sustained warmer than average temperatures increase the abundance and infection rate of Culex mosquito vectors, the mosquitoes that can carry West Nile virus.
Prior to 2018, the following number of positive mosquito tests have been reported in Toronto:
In 2014, 10 positive mosquito tests
In 2015, 18 positive mosquito tests
In 2016, 38 positive mosquito tests
In 2017, 62 positive mosquito tests
Symptoms for the virus are rare. Four out of five people who become infected do not experience any unpleasant symptoms due to the illness. However, the virus can have a much more serve effect on seniors and those with weakened immune systems. People who do get sick tend to develop symptoms within two to 15 days after being bitten. Symptoms include fever, headache, nausea, vomiting, body aches, skin rash, and swollen lymph glands.
To avoid mosquito bites, TPH says that it's important to wear clothing that covers their body, such as long sleeve shirts and pants. Always apply insect repellent before going outdoors in the summertime, and make sure that your home is fitted with tight screens on your windows and doors.
Toronto Public Health keeps a close watch on West Nile virus in the city. They report weekly on mosquito surveillance data, WNV-positive mosquitoes and human cases of the virus.