Cause of B.C. teen’s H5N1 avian flu infection still unknown, health officials say

Health officials in British Columbia are still puzzled by how a teenager contracted the H5N1 strain of avian flu, but they have confirmed that no further cases have been identified. The teenager remains in critical condition, with the Ministry of Health revealing that the individual is from the Fraser Health region, encompassing various suburbs of Vancouver and the Fraser Valley.

Avian influenza, also known as bird flu, primarily affects birds but can occasionally spread to humans through contact with infected animals or contaminated environments. While human infections with avian influenza are rare, they can range from mild to severe, potentially leading to pneumonia, organ failure, and even death.

Dr. Bonnie Henry, the Provincial Health Officer, expressed her concern for the teen and their family. She commended the extensive public health investigation led by the Fraser Health team, in collaboration with the B.C. Centre for Disease Control and other partners. The investigation involved testing pets, birds, and other animals from nearby areas, as well as conducting environmental testing of soil and water.

The investigation revealed that the strain of avian flu contracted by the teenager closely matched the strain found in wild birds in the Fraser Valley area in October. It was not directly linked to outbreaks at poultry farms in B.C., and there was no evidence of human-to-human transmission.

Since early October, the H5N1 virus has been detected in animals at multiple sites in B.C., including 22 poultry farms and various wild birds and small mammals like foxes and skunks. This recent outbreak is reminiscent of a similar incident in 2004 when two poultry farm workers in the Fraser Valley fell ill with the H7N3 strain of avian flu. H7N3 typically presents with mild symptoms, while H5N1 is known for its severe manifestations.

Globally, over 900 human cases of avian flu have been reported since 1997, primarily in Asia and Africa, with a high fatality rate. However, Health Canada warns that this rate may be overestimated due to underreporting of mild infections. In B.C., the Canadian Food Inspection Agency reported that as of November 20, 54 sites were actively dealing with avian flu infections, affecting an estimated 6.8 million birds.

In light of these confirmed cases among animals, officials advise residents to avoid direct contact with sick or dead animals, keep pets away from affected wildlife, and report any ill or deceased birds or mammals to provincial authorities. This proactive approach is crucial in containing the spread of avian flu and safeguarding public health.