A teenager in British Columbia, Canada, is critically ill in hospital with a suspected case of H5N1 avian influenza, marking the first potential human infection in the country. While initial tests indicate a strain of H5 bird flu, further testing is underway to confirm it is specifically H5N1. Authorities are investigating the source of the infection, which remains unknown.
The case was initially reported by British Columbia health officials on Saturday, October 28, 2024. The teen is currently receiving treatment at BC Children’s Hospital. As of Tuesday, October 31, 2024, the teenager’s condition remains critical. “Our thoughts are with this young person and their family during this difficult time,” stated Bonnie Henry, BC’s provincial health officer.
The emergence of H5N1 in a human in Canada follows a trend of increasing transmission of highly pathogenic avian influenza A (H5N1) from birds to mammals in recent years. In the United States, H5N1 has spread significantly among dairy cattle and other livestock in 2024. The U.S. has also reported 46 confirmed human H5N1 cases this year, primarily linked to contact with infected livestock or contaminated milk processing equipment.
While British Columbia has not reported any H5N1 cases in dairy cows, the virus has been detected in wild birds, small wild mammals, and poultry farms within the province. Since October 2024, at least 22 poultry farms in British Columbia have reported H5N1 infections. While contact with infected animals is the most likely source of the teenager’s infection, the exact transmission route remains unclear.
Though most human H5N1 cases in the U.S. this year have been mild, historical H5N1 outbreaks have had fatality rates as high as 50%. Health officials have not disclosed much information about the affected teenager, but have indicated that the teen has no pre-existing health conditions that would increase the risk of severe illness. The teenager initially experienced symptoms including conjunctivitis (pink eye), cough, and fever over a week before being hospitalized.
Health officials in the U.S. have maintained that the current H5N1 cases in cows and humans pose a low risk to the public. Thirty-six individuals who had recent contact with the infected teenager in British Columbia have been tested, and none have shown signs of infection.
However, the lack of a clear source for the teenager’s infection raises the possibility of further undetected transmission within the community. The long-term concern remains the potential for H5N1 strains to adapt further to mammals and humans. If the virus acquires mutations that facilitate efficient human-to-human transmission while maintaining high virulence, it could trigger a pandemic. Each new human case increases the likelihood of this scenario.
