Bird flu detected in a US pig for the first time

A pig at a farm in the US state of Oregon is infected with bird flu, raising concerns about the virus’ potential to affect humans.

The H5N1 case was the first time bird flu was detected in swine in the US.

The infection happened at a backyard farm where different animals share water and are housed together.

Last week, poultry at the farm were found to have the virus and testing this week found that one of the farm’s five pigs had become infected.

The farm was put under quarantine and all five pigs were euthanised so additional testing could be done.

It’s not a commercial farm, and US agriculture officials said there is no concern about the safety of the nation’s pork supply.

But finding bird flu in a pig raises worries that the virus may be hitting a stepping stone to becoming a bigger threat to people, said Jennifer Nuzzo, a Brown University pandemic researcher.

Pigs can be infected with multiple types of flu, and the animals can play a role in making bird viruses better adapted to humans, she explained.

For instance, the 2009 H1N1 flu pandemic had swine origins.

“If we’re trying to stay ahead of this virus and prevent it from becoming a threat to the broader public, knowing if it’s in pigs is crucial,” Nuzzo said.

The USDA has conducted genetic tests on the farm’s poultry and has not seen any mutations that suggest the virus is gaining an increased ability to spread to people.

That indicates the current risk to the public remains low, officials said.

Previous bird flu cases in pigs

A different strain of the bird flu virus has been reported in pigs outside the US in the past, and it did not trigger a human pandemic.

“It isn’t a one-to-one relationship, where pigs get infected with viruses and they make pandemics,” said Troy Sutton, a Penn State researcher who studies flu viruses in animals.

This version of bird flu, known as Type A H5N1, has been spreading widely in the US among wild birds, poultry, cows, and a number of other animals.

Its persistence increases the chances that people will be exposed and potentially catch it, officials say.

It isn’t necessarily surprising that a pig infection was detected, given that so many other animals have had the virus, experts said.

The Oregon pig infection “is noteworthy, but does it change the calculation of the threat level? No it doesn’t,” Sutton said.

If the virus starts spreading more widely among pigs and if there are ensuing human infections, “then we’re going to be more concerned”.

So far this year, nearly 40 human cases have been reported in the US with mostly mild symptoms, including eye redness, reported. All but one of the people had been in contact with infected animals.