ScienceInsider

The pig herd infected with swine flu in Alberta, Canada, appears not to have been infected by a worker at the farm who had recently returned from Mexico with flu-like symptoms. As these were the first pigs ever found to harbor the virus, this obviously raises the possibility that they infected humans and played a role in the origin of the outbreak.

According to a 6 May “situation report”  issued by the European Centre for Disease Prevention and Control, Canadian veterinary officials sent an update report to the European Commission with the new information about the farm worker. “The report states that the Canadian contractor, who was working with this swine herd, developed influenza-like illness after travel to Mexico, but tested negative for influenza A (H1N1) after recovery,” the situation report says. “Two weeks after the return of this contractor, the pigs from this particular farm evidenced fever and loss of appetite, without mortality, and tested positive for influenza A with H1 subtype.” The Canadian Food Inspection Agency (CFIA) quarantined the farm, which was first reported to have 220 of the herd’s 2200 pigs infected with the virus.

ScienceInsider had arranged an interview yesterday with CFIA veterinarian Jim Clark, and it was abruptly canceled this morning 10 minutes before the scheduled time. “Due to a scheduling conflict, Dr. Jim Clark, our spokesperson on the Swine flu case, will be unable to address the media this morning,” wrote an agency media spokesperson in an e-mail.

—Jon Cohen