Editorial: First human death of bird flu in the US a worrying development, but not cause for alarm

Scientists have been growing increasingly concerned by the spread and evolution of H5N1 avian flu, which has killed tens of millions of poultry birds in four years and been detected in two dozen countries. Photo / 123rf

Editorial

Recent headlines about bird flu spreading in poultry farms and dairy cattle herds overseas may cause some concern, but it is important to keep facts in mind so we understand that, while we should be on alert, we should not be alarmed.

News that bird flu had been found on a free-range chicken farm in North Otago raised alarm in New Zealand last month. The Ministry for Primary Industries said laying hens foraging outside were thought to have been infected with the H7N6 strain through a low pathogenic virus from wild waterfowl.

This week, a man in the US state of Louisiana became the first human death of bird flu in the country.

One very important point to make is that from the outset, while both of those are instances of bird flu, the strain recently found in New Zealand is not the same that killed the man, who died of H5N1.

The patient was a 65 year old with underlying health conditions who tested positive for the virus in mid-December and was sent to hospital soon after.

According to the US Centre for Disease Control (CDC), the man is believed to have caught the disease directly from birds kept on his property.

While news of the Louisiana man’s death may cause some alarm, it is important to keep a few facts in mind.

The H5N1 virus is not new. This avian influenza variant was first detected in 1996, but a record global outbreak since 2020 has led to hundreds of millions of poultry birds being culled – and an unknown but large number of deaths of wild birds.

While this is the first human death of bird flu in the US, outside of that country and over the last 25 years, more than 950 cases of H5N1 bird flu have been reported to the World Health Organization (WHO). About half of those – 464 people – have died.

In March last year, the virus started transmitting between dairy cows in the United States. Since April, the US has confirmed 61 human cases in the country, mostly in workers on dairy farms where the virus infected cattle.

According to the CDC, no person-to-person transmission spread has been identified. As with the case in Louisiana, most bird flu infections are related to animal-to-human exposures. There are also no concerning virologic changes actively spreading in wild birds, poultry, or cows that would raise the risk to human health.

However, scientists are concerned that H5N1 is potentially just one mutation away from developing the ability to transmit from one person to another.

Tom Peacock, a virologist at the Imperial College London, told AFP that, in his opinion, “the biggest error the US has made is its slow and weak response to the cattle outbreak”.

The reason bird flu was affecting US cattle seemed to be a combination of this weak early response, poor biosecurity, “and the intensification of US dairy farming (which involves far more movement of animals than any European system),” he told the news agency.

Dr Peter Chin-Hong, an infectious disease physician at UCSF Health, told NBC News in the US he was very concerned when news about the severe case in Louisiana was first announced in December.

“I’m not saying this is a cause for panic right now. But in the medium term, I think all the signs are pointing to the temperature rising with bird flu in terms of its potential impact on humans,” Chin-Hong said.

According to the WHO, the bird flu risk to humans remains “low”.

“We are concerned, of course, but we look at the risk to the general population and ... it still remains low,” WHO spokesperson Margaret Harris told media at a Geneva press briefing.

Harris also said the US is doing “a lot of surveillance” in this area and the Government has also recently allocated an additional $306 million to bolster H5N1 surveillance and research programmes.

The WHO does not currently consider the bird flu outbreak a global health emergency. However, there are growing calls for the US Government to step up its efforts to stave off any threat to humans, particularly as Donald Trump prepares to return to the White House with vaccine-sceptic Robert F. Kennedy jnr as his health secretary. How the US deals with the current outbreak will influence how the outbreak impacts – or not – the rest of the world.

In the meantime, it’s important to keep in mind that avian flu has been around for a while and, despite recent headlines, there is no cause for alarm.