H5N1 | Should Canada test all flu patients?

U.S. authorities recommend that all patients hospitalized with influenza A in the United States be tested for H5N1 avian influenza. Should Canada follow suit?

Why are US hospitals testing flu patients?

Because there have been many human cases of H5N1 over the past year in the United States, said Thursday in a press conference call Demetre Daskalakis, director of the Center for Immunization and Respiratory Diseases at the Centers for Disease Control and Prevention. (CDC) of the US government. More precisely, 66 cases in 2024, compared to zero in 2023.

“Currently, it takes several days to know if a patient has H5N1. Sometimes he has already been discharged from the hospital. And his memories of what he did 7 to 10 days before, which allows us to see how he became infected, may be imprecise,” said Mr. Daskalakis.

For this reason, the CDC recommends that as soon as a hospitalized patient has a flu test indicating that the virus is strain A, they should undergo subtyping testing. If the subtyping is H1 or H3, it is the common flu. If it’s not H1 or H3, it’s probably H5N1, and a third test will need to be done at the CDC labs.

At the hospital, the first two steps should be completed within 24 hours. “We want to know what’s happening now, not what happened a week ago,” Mr. Daskalakis said.

In Canada, have there been cases of H5N1 avian influenza in humans?

There were two: the first in 2014, then another last fall in British Columbia. This is a 13-year-old girl who spent two months in hospital. She even had to be hooked up to an extracorporeal breathing machine.

His H5N1 infection was detected accidentally, thanks to the use of a relatively expensive test and, for this reason, little used, according to pediatrician Jesse Papenburg, microbiologist-infectious disease specialist at the Montreal Children’s Hospital.

“It’s a test that directly informs us whether it’s H1 or H3,” he explains. Since it was neither, H5N1 was suspected. »

The teenager was given stronger antiviral drugs as soon as her doctors suspected it was bird flu. If she had taken an ordinary test which would only have shown that she had influenza A, she would not have received these drugs so quickly, emphasizes the D^r Papenburg.

Will Canada follow the United States and test flu patients?

The D^r Papenburg thinks that should be the case. But Jean-Pierre Vaillancourt, from the faculty of veterinary medicine at the University of Montreal, believes that the decision should be made based on the regional context.

“In Quebec, we have four outbreaks of avian flu in chicken coops, and it is not H5N1. On the other hand, in British Columbia, there have been 76 outbreaks of H5N1 in poultry houses in recent months. So yes, it would be good to have quick subtyping. »

Judith Fafard, medical director of the Quebec Public Health Laboratory, agrees with the D^r Vaillancourt.

She emphasizes that steps are underway to prepare for the rapid implementation of such a subtyping program. “We don’t want to wait until we have problems before preparing for a more concrete threat,” says the D^re Fafard.

Also, when Public Health receives a report of a case of influenza that could be H5N1, in a poultry farmer, for example, a direct test for H1 and H3, as in British Columbia, is recommended. This happens “once or twice a month”, specifies the D^re Fafard.

Health sector cuts pose obstacle to rapid subtyping of influenza A cases, says D^r Papenburg. “We seem to have forgotten the pandemic preparedness resolutions taken after COVID-19. »

The D^re Fafard confirms that “budgetary rigor” affects laboratories, both provincial and federal. A federal program to support genomic analyzes ends on March 31, and possibly also a program to monitor viruses in wastewater. Fortunately, unlike other provinces, Quebec also subsidizes these two programs.

“It should allow us to keep the team in place, but it is certain that the room for maneuver is greatly reduced,” comments the D^re Fafard.

Is H5N1 avian flu dangerous for humans?

The bovine version, which has been in the news since its detection in Texas last March, but which is not present in Canada, does not produce many symptoms, neither in cows nor in humans, according to the D^r Vaillancourt. But the H5N1 that affects chickens is slightly different and can make humans much sicker. In early January, a 65-year-old man who had health problems became the first American to die from H5N1 bird flu.