MONTREAL — Soaring cases of respiratory syncytial virus in Quebec have pushed the positivity rate to 15 per cent in Montreal and Quebec City.
Weekly provincial surveillance data ending Oct. 22 show positivity rates of the childhood illness hover just over 13 per cent provincewide, with slightly higher rates in the two cities and wide variation among smaller communities.
It’s several times the most recent federal positivity rate of 3.5 per cent, although that data is a week behind and covers the week ending Oct. 15.
The head of the pediatric emergency department at Montreal's CHU Sainte-Justine said Tuesday his emergency rooms “are completely jammed with patients” with respiratory viruses, largely driven by RSV.
"There's just so much more — a larger wave with sicker patients therefore more hospitalizations, and our hospitals are just full to the brim," Dr. Antonio D’Angelo said Tuesday.
"In the emergency rooms, well, they're just all over the place — they're in our respiratory unit in the emergency room but they're also in sort of a makeshift corridor for a temporary unit there. And then we had to open up another corridor with patients with respiratory cases that needed treatments.
"And that's very, very unusual. In fact, we've never had it this bad."
A pediatric infectious disease specialist at the Montreal Children's Hospital reported similar spikes there, noting that admissions suggest Quebec is already in the middle of a very bad RSV season when normally it shouldn't have even started yet.
Dr. Jesse Papenburg explained the early onset as the legacy of a similarly early and intense RSV season last year. He said it began in September 2021 and "was over" by January, when other provinces hadn't even yet reached their peak.
As for why Montreal saw the early spike, he said France and New York City each saw springtime RSV outbreaks in 2021. Since both regions attract a lot of travel from Montreal, it's possible that importation combined with a susceptible population and easing pandemic measures created the right circumstances for a summer surge.
Further adding to the burden this year is the fact RSV seems to be hitting more than just babies and toddlers to include three- and four-year-olds, who are getting the virus for the first time because they had been shielded by now-lifted pandemic precautions, said D’Angelo.
D'Angelo said he expected similar rates to emerge in other Canadian centres, acknowledging that other hospitals are already seeing increasing numbers of respiratory patients, as well as strained resources and staff.
The national figures show a positivity rate of two per cent in Ontario and 3.4 in Atlantic Canada. The lowest rates were 1.4 per cent in British Columbia, one per cent on the Prairies and two per cent in the Territories.
Ottawa pediatric hospital CHEO said for the week ending Oct. 15, out of 298 RSV tests 30 were positive — about 10 per cent.
A CHEO spokesperson said 12 patients were hospitalized for RSV last month — the same record-high number as last year, and much higher than the pre-pandemic average of about one to two hospitalizations for September.
D'Angelo said RSV typically spreads by community, and does not generally emerge at the same time across the country.
"It often happens where there'll be one sort of epicentre where everything sort of starts to occur, and then it sort of spreads out," he said.
D'Angelo said strain at his hospital was compounded by the fact that about 30 per cent of patients there don't have a family physician and end up going to emergency with minor ailments that otherwise could be treated elsewhere.
"Now everything's sort of by appointment instead of just walk-in," he said, believing more walk-in clinics could address hospital demand.
"With the amount of viruses that we're seeing, a lot of these docs don't have any more time available for their own patients, which is kind of sad."
While only a small percentage of RSV cases result in hospitalization, the illness is common among children. By age two, 90 per cent of kids will have had an RSV infection, said Papenburg.
However, some infants are at greater risk of severe illness and that's when it's important to be have a predictable viral season, he said.
The RSV season typically runs from November to March but Quebec experts noticed a five per cent positivity rate in August, said Papenburg.
He said that prompted the province to move a preventive campaign for high-risk babies to mid-September, instead of the usual November.
A monoclonal antibody injected monthly to very high risk infants can cut their risk of hospitalizations by half, he said. These may include children younger than one year of age who were born very prematurely, or who have congenital cardiac disease or chronic lung conditions.
— With files from Cassandra Szklarski in Toronto.
This report by The Canadian Press was first published Oct. 25, 2022.
The Canadian Press
Note to readers: This is a corrected story. A previous version stated Quebec's provincial RSV rates were nearly 14 per cent. In fact, they were slightly over 13 per cent.
