Viruses limited by COVID-19 restrictions are coming back strong this fall, experts say

If you've felt sick at any point over the past year and a half, COVID-19 was likely your main concern. But with public health measures easing in many places and more people travelling, a variety of other respiratory viruses are reappearing this fall. 

Dr. Zain Chagla, an infectious disease physician and associate professor at McMaster University in Hamilton, said common respiratory viruses such as enterovirus and rhinovirus — which causes the common cold — saw low rates of transmission last winter due to physical distancing and mask wearing. But they began circulating more widely over the summer. 

"We've now completely altered the seasonality of these and have reintroduced them back in the population," Chagla told Brian Goldman, host of White Coat, Black Art and The Dose. "We're seeing very atypical patterns of disease that we've never seen before."

All of this means keeping an eye out for the return of some old, familiar illnesses.

With children back in school, expect even more enterovirus and rhinovirus in the coming weeks, said Chagla.

Parainfluenza, which he described as "a cousin of influenza," showed up again in parts of Canada in July and August. Parainfluenza is caused by a different virus, but the symptoms are similar to influenza, including fever, cough and sore throat.

As for influenza itself, Chagla said it's difficult to predict what kind of flu season Canada is in for.