Ottawa, March 22 (IANS) Canada's Chief Public Health Officer Theresa Tam announced that the country is witnessing a steady increase in the number of new cases of Covid-19 variants.In its latest update on Sunday, the Public Health Agency of Canada said that as of March 18, a total of 4,499 variant cases have been reported, reports Xinhua news agency."In parts of Canada, variants of concern represent an increasingly high proportion of cases and are being associated with a greater number of outbreaks," Tam said in a statement on Sunday."Circulation of Covid-19 in younger, more mobile and socially-connected adults presents an ongoing risk for spread into high-risk populations and settings," she added.On March 18, Canada's most populous province of Ontario, with a population of 14 million, declared that a third wave of the pandemic was underway due to increasing Covid-19 variant cases.Canada has so far reported a total of 933,230 coronavirus cases, with 22,673 deaths.The country's latest national-level data show a seven-day average of 3,297 new cases daily on March 12-18. Currently, there are 34,283 active cases across the country.While Covid-19 continues to impact people of all ages in Canada, infection rates are the highest among those aged 20-39 years of age, Tam said in Sunday's statement. --IANS ksk/