Worrying bird flu strain undisclosed by US after Trump orders WHO exit

US officials are investigating the appearance of a strain of bird flu identified in the country for the first time, a worrying sign that the virus is evolving in ways that could make it harder to contain.

Detected on a duck farm in Merced County, California, it’s the first confirmed case of H5N9 in poultry in the US, according to the website of the World Organisation for Animal Health, a Paris-based group focused on animal diseases.

Day-old duck hatchlings crawl around inside an incubator at a duck farm in New York state.Credit: AP/File

The California case wasn’t announced by US health officials, as the Trump administration has paused government communications on health topics pending a political review. Scientists worry that could delay the release of essential information to the public, including about disease outbreaks.

“It is extremely unusual, and I believe it reflects the policy decision for everyone to go dark,” said Michael Kinch, a vaccine specialist and chief innovation officer at Stony Brook University. “It’s troubling because any sort of non-typical influenza is particularly problematic when it gains the ability to jump between species.”

US officials are required to report diseases in animals to the World Organisation for Animal Health, according to the US Department of Agriculture (USDA) website. The US agency didn’t respond to requests for comment on why it didn’t report the case publicly.

This week, public health officials were told to stop working with the World Health Organisation, effective immediately.

Donald Trump’s second administration is pulling out of world health bodies, which experts say will delay important disclosure of new diseases.Credit: AP

A US Centres for Disease Control and Prevention official, John Nkengasong, sent a memo to senior leaders at the agency on Sunday night telling them that all staff working with the WHO must immediately stop their collaborations and “await further guidance”.

Experts said the sudden stoppage was a surprise and would set back work on investigating and trying to stop outbreaks of Marburg virus and mpox in Africa, as well as brewing global threats. It also comes as health authorities around the world are monitoring bird flu outbreaks in US livestock.

New strains of bird flu are concerning as the disease has caused hundreds of deaths in people over the years, mainly via exposure to infected animals, and the USDA and state officials are investigating the case.

A more common bird flu strain, H5N1, has recently been spreading in US farm animals, and a woman died after contracting the disease in Louisiana, although severe cases in people have been rare.

H5N9 is a subtype of bird flu, and a version that appeared in China more than a decade ago was “highly pathogenic,” according to a 2015 academic paper by researchers in the country. The H5N9 version is thought to come from a genetic combination of other bird flu viruses, including H5N1.

Concerns about H5N1, which has been known and studied for more than a decade, have been rising since a death was linked to the virus in Louisiana earlier this month. H5N9 is a less researched viral strain. If it became widespread in humans, scientists would likely have to start from the beginning in terms of researching it and developing vaccines, Kinch said.

“This the wrong time of year and the wrong virus to be messing around with,” Kinch said.

US health officials have been monitoring the H5N1 virus for genetic mutations that could make it more dangerous. For now, they say there’s no evidence of human-to-human spread, and the risk to the public remains low.

Still, the new case shows that H5N1 is starting to mix genetic material with other influenza viruses, “which is concerning”, said vaccine expert Peter Hotez, dean of the National School of Tropical Medicine at Baylor College of Medicine.

Richard Webby, a specialist in influenza at St Jude Children’s Research Hospital in Memphis, said the new H5N9 case didn’t itself appear to raise the risk to humans or animals. Still, he said, researchers needed to look closely at the genetic sequence to see if any important changes have occurred.

“Anytime a flu virus mutates or evolves, we can’t predict the end result of that,” Webby said.

Meanwhile, in Britain, health authorities have detected a H5N1 case in a person in central England but added that the risk to the wider public remained “very low”.

The person acquired the infection on a farm, where they had close and prolonged contact with numerous infected birds, the UK Health Security Agency said in a statement.

It said the individual was well, and authorities were tracing all known contacts of the person to offer antiviral treatment.

“We have robust systems in place to detect cases early and take necessary action, as we know that spillover infections from birds to humans may occur,” said UK Strategic Health Authority chief medical adviser Susan Hopkins.

British authorities have detected cases of bird flu in poultry farms in recent months and have taken steps to cull all infected animals.

Bloomberg, Reuters