Youngest residents now account for largest share of new COVID-19 cases in Manitoba

The face of the COVID-19 pandemic in Manitoba is getting younger as the province's youngest residents now make up the biggest proportion of new cases.

Since mid-June, those in the age category 0-18 have made up more than a third of all new cases, and almost every week have produced the most new infections, according to provincial government data.

Ahead of the rising fourth wave driven by the delta variant, some public health experts worried about what might happen when students — many of whom are ineligible for a vaccine — head back to school.

"In this wave, what we are seeing is a different profile of cases and maybe even the consequences of COVID-19 like hospitalization," said Dr. Nazeem Muhajarine, a professor of community health and epidemiology at the University of Saskatchewan.

Of the 4,283 cases recorded between June 13 and Aug. 28, 1,554 were between the ages of 0 and 18.

In each of the province's weekly reports during that time, except for the week of July 25, the number of cases in the youngest age category either exceeded or equalled the number between 19 and 34, which had previously seen the highest numbers.

Rising vaccinations

Part of the reason for this shift is rising vaccination rates among eligible Manitobans.

"Vaccines have definitely changed the complete, entire landscape of our experience with this virus," said Dr. Santina Lee, a pediatric infectious disease physician and a medical officer of health with the provincial government.

"This virus … it's very good at finding the populations who are susceptible. So that includes people who are not fully vaccinated."

Another reason is the fact that household contacts of known cases are advised to get tested, even if they are asymptomatic, said Dr. Marni Hanna, president of the Manitoba Pediatric Society.

"Many times, those are children, and so some of the COVID cases in children have been children who are not very sick," she said.

Of the 1,554 cases in Manitobans 0-18 years old, 17 ended up in hospital, and none needed admission to an intensive care unit.

While she understands concerns some might have about the potential for an increase in cases when kids return to school later this week, Hanna said studies last year found the vast majority of cases among children came from close household contacts.

Delta variant

The big difference going into this school year, Hanna said, is the presence of the delta variant, which is significantly more infectious than other coronavirus variants that have been identified.

"The more people that you have infected, the more likely you are to potentially have cases that wind up being more severe," she said.

One recent study based in the United Kingdom, which was also published in the science journal The Lancet, suggests that the new delta variant could cause more severe illness than the previous alpha variant, although it is unclear how much more severe.

Muhajarine says the U.K. study suggests the delta variant could be 2.5 times more virulent.

"So you have a variant that is highly threatening and kids who are not vaccinated, who are being susceptible to it and being infected," he said.

Subgroup analysis of the data looked at the effects of the delta variant on people who are vaccinated compared to unvaccinated. 

"And this increased virulence seems to be mainly only affecting those people who are not vaccinated," said Lee.

Worldwide trends show an increasing number of young people testing positive for the virus, Muhajarine said.

Schools need to take multiple precautions to make sure students are safe this year, he said.

While the Saskatchewan government has allowed school divisions in that province to implement their own COVID-19 control measures, Manitoba has made masks mandatory for all grades, and will require all school staff to either get a vaccine or take frequent tests.

All governments need to pay attention to case numbers among their youngest residents after school resumes this coming week, Muhajarine said.