A teen in critical condition at BC Children's Hospital is the first domestically acquired case of H5N1 avian influenza, Canada's public health agency confirmed Wednesday (Nov. 13).

The Public Health Agency of Canada said that based on genomic sequencing, the case is related to the avian influenza H5N1 viruses from the ongoing outbreak in poultry in B.C.

However, the investigation has not yet determined how the teen became infected. Contact tracing, testing and offering antiviral medications to contacts is continuing in B.C. 

There have been no further cases identified at this time, the public health agency said.  

B.C.'s Health Ministry and provincial health officer Dr. Bonnie Henry first shared news of the suspected case on Saturday, the day after the teen was admitted to hospital.

, Henry said the province was waiting on official test results from the Public Health Agency of Canada's National Microbiology Laboratory in Winnipeg to confirm it was a case of avian influenza, but her office was confident in their testing.

The Public Health Agency of Canada said human infection with avian influenza is rare and usually occurs after close contact with infected birds, other infected animals or highly contaminated environments. 

There is an ongoing outbreak of avian influenza in dairy cattle in the U.S., there are no reported cases in dairy cattle in Canada and there is no evidence of avian influenza in samples of milk in Canada. Milk and milk products that have been pasteurized are safe to consume. 

The public health agency added that the clade 91ÂãÁÄÊÓƵ“ a grouping of organisms that are believed to have a common ancestor 91ÂãÁÄÊÓƵ“ from the H5N1 avian influenza in U.S. dairy cattle is not the same as the clade in the domestically acquired human case in B.C.