Not just seniors are being hard hit by the novel coronavirus sweeping Alberta, says an infectious disease specialist.

The latest breakdown of the province's COVID-19 hospitalizations, updated Sunday, shows that 41 per cent of patients are aged 35-54.

This reveals that young and middle-aged active people can experience severe symptoms from the respiratory illness, said Dr. Craig Jenne, an associate professor with the infectious diseases department at the University of Calgary.

"This is not a disease only of senior citizens or people with underlying comorbidities or underlying conditions," Jenne said. "Everybody's at risk of getting infected."

Data gathered by Alberta Health shows that roughly equal numbers of those aged 35-54 and 55-79 have been hospitalized, despite fewer of the elder group being infected.

Based on Sunday's update of 661 cases, roughly 35 per cent of cases involved people aged 35-54, and 25 per cent of cases were people aged 55-79. Yet the two groups made up nearly the same amount, roughly 40 per cent each, of hospitalizations.

"What we know about the disease is … the fatalities and the intensive care hospitalizations tend to occur more frequently in the older people," Jenne said. "However, in the community, they are the minority of the actual infections."

The severity of disease is more pronounced with older people, he said. But younger and middle-aged people, he said, may be seeing equally high numbers of severe reactions due to more of them getting infected.

Those under 55 may be working and travelling more, Jenne said, opening themselves up to risk, and thus boosting those hospitalization rates.

"They've travelled more, they're continuing to go to work, even when recommendations were to maybe isolate at home," Jenne said. "So there's a bigger risk that they actually get infected."

Craig Jenne, who teaches microbiology and infectious diseases at the University of Calgary, says Alberta Health's numbers show that young and middle-aged people are at risk of hospitalization, too. (Jennifer Lee/CBC)

In total, as of Sunday, 41 Albertans had been hospitalized, with 14 intensive care unit (ICU) admissions. The province wasn't able to provide an age breakdown for ICU admissions.

The total numbers of COVID-19 confirmed cases and hospitalizations have been updated daily in Alberta. The health authority has been able to update the age breakdown slightly less regularly.

Here are the numbers of people, by age group, hospitalized with COVID-19 as of March 29:

15-19 years — 1 case.

— 1 case. 25-34 years — 1 case.

— 1 case. 35-44 years — 6 cases.

— 6 cases. 45-54 years — 11 cases.

— 11 cases. 55-64 years — 6 cases.

— 6 cases. 65-79 years — 10 cases.

— 10 cases. 80+ years — 6 cases.

Health authorities recommend everyone in Alberta stay home as much as possible, stay at least two metres from other people when out of their homes, wash their hands frequently and avoid touching their faces. Gatherings have been limited to 10 or fewer people.

Anyone with symptoms, even mild ones of sniffles, sore throat, coughing or fever, has been directed to self-isolate immediately. The province recently released new guidelines to help with self-isolation.

Alberta Health Services has an online self-assessment tool to help people understand what to do.