British Columbia health officials have yet to identify a likely source of the infection, though none of the teen's contacts have tested positive for the virus so far.

Health officials in British Columbia have reported the first presumptive case of H5 avian influenza in a human in Canada.

Two states affected by avian flu outbreaks in dairy cattle and commercial poultry reported more probable H5 avian flu infections in farm workers over the last few days, four in California and three in Washington.