The two, a hospitalized 80-year-old-man and a 32-year-old woman recovering at home, are the city's first announced cases this summer, but unlikely to be the last, said Dr. Howard Shapiro, Toronto Public Health's associate medical officer of health.
"We are headed toward what is considered a peak period for West Nile virus," he said, adding that the proliferation of the virus was advanced by the city's mild winter, followed by a hot summer.
One in five people bitten by an infected mosquito experience symptoms including fever, headache, body aches and sensitivity to light. Less than 1 percent become seriously ill with symptoms including brain inflammation, the Toronto Star said Friday.
There were 28 cases of West Nile virus in Toronto in 2011. The city has seen no deaths from the virus since 2005.