Rare human swine flu case deemed low threat in Alberta

Influenza A (H1N2)v is linked to contact with pigs, and provincial officials continue their investigation into potential sources of the virus

A case of swine influenza contracted by a person in central Alberta is believed to be an isolated incident with low threat to either other people or to pigs.

Dr. Deena Hinshaw, Alberta’s chief medical officer of health, said Nov. 4 that it was the first reported case in Canada of a person getting this particular flu, called influenza A (H1N2)v. Worldwide there have been only 27 cases since 2005, all connected to direct or indirect contact with pigs and none have led to “sustained human to human transmission.”

The virus is not easily transmitted between people.

“Influenza viruses that normally circulate in pigs, including H1N2, can infect people although this is not common,” said Hinshaw.

The case was detected in mid-October when the affected person sought medical care for signs of flu.

“The patient experienced mild symptoms, was tested and then quickly recovered,” said Hinshaw. “There was no evidence at this time that the virus had spread further.”

H1N2 influenza in hogs is a provincially notifiable disease, which means veterinarians must report any cases within 24 hours of discovery. That brought Alberta’s chief veterinarian Dr. Keith Lehman into the picture.

As of Nov. 4, the investigation into the source was ongoing.

“There is no evidence of risk to the public. H1N2 is not a food-related illness. It is not transmissible to people through pork meat or other products that come from pigs. There is no risk associated with eating pork,” Hinshaw said.

Lehman said potential sources were being checked. However, influenza among pigs is not unusual in any operation here or around the world.

In Alberta pigs, he said there might be 10 to 30 cases per quarter, on average.

“It is a virus that is not uncommon in our swine populations,” said Lehman. “Typically when we do have influenza in our swine populations it’s actually not even uncommon for it to be in a herd and not show any signs of clinical disease. But when it does show up, typically it’s pretty mild.”

He said this particular strain of influenza has become more prevalent in recent years but is not considered a major threat. Biosecurity measures typical in swine operations limit the risk of spread to other farms.

Symptoms of H1N2 in pigs include fever, sneezing, breathing difficulties, eye redness and lack of appetite. Though rare, it can spread to humans, as the recent case indicates.

In people, it manifests with the common flu symptoms, which are generally mild and resolve within a week to 10 days.

Those in contact with pigs can protect themselves by frequent hand washing and avoiding contact with pigs that appear ill. If such contact is necessary, they should wear protective clothing, gloves and masks, says Alberta government advice on the virus.

Hinshaw said optional influenza testing will be offered to residents in parts of central Alberta if they come for COVID-19 testing at an Alberta Health Services assessment centre.

H1N2 was discovered in this incident through regular protocols that test samples for a range of viruses, including COVID and influenza. The affected person followed all instructions regarding care and recovery, Hinshaw said.

“There was nothing about the presentation or the history that indicated any different concern than anyone else presenting with… influenza-like illness symptoms.”

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