N.B. sees far more RSV cases than other Atlantic provinces, federal data shows

New Brunswick has more lab-confirmed cases of respiratory syncytial virus, or RSV, than the other three Atlantic provinces combined, according to the latest figures posted by the Public Health Agency of Canada.

Ninety-nine New Brunswickers tested positive for the virus during the week ending Feb. 24, the federal website shows.

There were 96 confirmed cases in the rest of the region: 41 in Newfoundland, 32 in Nova Scotia, and 23 in Prince Edward Island.

RSV is a common respiratory virus most children contract by the age of two. It usually causes a mild illness with cold-like symptoms, but it can result in hospitalization and even death.

Infants, people aged 65 or older, and people who are immunocompromised are considered most at risk for developing severe illness, according to the Public Health Agency of Canada.

No information about how many of the New Brunswick cases required hospitalization or resulted in death is available because RSV is not a reportable disease in the province, as it is in some other jurisdictions.

No age breakdowns of cases are available either.

Unclear if seasonal peak reached yet

Last month, Dr. Yves Léger, New Brunswick's acting chief medical officer of health, said he anticipated increasing RSV activity would peak soon. He said he expected this to be a "more typical season" than last year.

New Brunswick recorded 2,066 RSV cases in 2022-23 — the highest number in at least a decade.

By comparison, there were 371 cases in 2022-23 and during the previous year, when COVID-19 protective measures, such as masking and physical distancing, were in place, no RSV cases were confirmed.

The 99 RSV cases diagnosed last week raise the total so far this respiratory season to 1,520, the national website shows.

At this time last year the province had 1,877 confirmed cases.

The respiratory season continues into August.

"It's too early to tell whether … a peak has been reached," said Department of Health spokesperson Katelin Dean.

"However, the number of RSV infections detected this past week has shown a decrease compared to the previous week."

There were 105 new cases detected during the week ending Feb. 17, according to the federal website, putting New Brunswick in the lead again, among the Atlantic provinces, representing almost half of the four-province total of 212.

Positivity rate almost double national figure

"At a national level, the most recent surveillance report is indicating that RSV activity is stable and remains below expected levels for this time of year," Dean said.

Across Canada, there were a total of 1,276 new RSV cases detected last week. The national positivity rate —  the percentage of the total lab tests performed that produced a positive result — was 4.5 per cent.

New Brunswick's positivity rate was 8.5 per cent.

Health Canada has approved a new RSV vaccine for use in pregnancy to protect infants from birth to six months, and for seniors 60 and older.

It's unclear if or how soon New Brunswick might offer the vaccine.

The province is awaiting recommendations from the National Advisory Committee on Immunization, Léger has said.

Could be added to Respiratory Watch report

Asked for an update on making RSV a reportable disease in New Brunswick, Dean said the province is "working towards making RSV part of its Respiratory Watch report for next respiratory illness season."

As it stands, the province does not monitor and report on RSV cases in the same ways that it does for COVID-19 and the flu. It simply inputs RSV test data into the national respiratory virus detection surveillance systems weekly.

If RSV was a reportable disease under the Public Health Act, laboratory staff from all regional hospitals would have to submit test results to the regional Public Health team, where additional information would be collected about each case for analysis.

Last month, Léger said changes to the act had been proposed and were "making [their] way through the machinery of government."