A four-year-old boy in China has been diagnosed with the avian flu — the H3N8 strain. Although the strain can also infect dogs and horses, researchers believe the boy got the disease from birds, as he was exposed to chickens and crows at home.
The risk of human transmission is very low, researchers say — and that’s probably the most important thing for now. Just because the virus jumped from bird to human doesn’t mean it can jump from human to human as well. For now, there’s no reason to believe it will go any further.
That being said, it’s still concerning.
In a statement, China’s National Health Commission (NHC) said the flu was found in Henan province, a landlocked area in east-central China. The child apparently developed severe symptoms that started with a fever, and a few days later got worse. Eventually, he had to be admitted to a local medical facility, where it was confirmed that he had the H3N8 influenza strain. The patient lived on a farm, and none of his family exhibited any symptoms.
H3N8 originated in the 1960s, as a subtype of equine influenza in Miami. It’s a subtype of the Influenza A virus that is now endemic in birds, horses, and dogs. Between 1978 and 1981, there were large epidemics of the strain across much of the US and Europe — despite the development of vaccines (which the virus appeared capable of evading at least partially). Since then, the H3N8 has diverged into two main groups: an “American” one and a “European” one. According to a study from 1997, the virus is responsible for about one-quarter of influenza infections in wild ducks. This fits with the current case as well, as the boy’s virus may have come from chickens (which his family raised) or from wild ducks (which live close to his home).
Analysis of the virus inside the boy showed that the infection came directly from birds, and according to the NHC, it was a “one-off cross-species transmission, and the risk of large-scale transmission is low”. This is far from the first avian influenza that jumped to humans. Previous strains include H5N1, H7N9, H5N6, H5N8, and now H3N8.
Even as this episode may not cause widespread problems, it’s yet another reminder that viruses are never too far away. We’re not nearly done with the ongoing coronavirus pandemic, but that doesn’t mean that the risk of having a new virus pop up from animals is any lower. In fact, our interaction with animals (both farm and wildlife) makes the risk of a new pandemic higher than ever.
Alexandra Phelan, assistant professor at the Center for Global Health Science and Security at Georgetown University, told The Guardian that this is yet another sign that we need to increase international surveillance “Apart from H3N8, we have seen a number of other new spillover events of influenza from poultry to people over recent years including H5N8 in Russia and H7N9 and H10N3 in China,” she said.
Meanwhile, the avian flu continues to cause a record number of outbreaks in birds across the UK, the US, and Europe this year. In the UK, consumers can no longer purchase free-range eggs from birds that have been allowed outdoors since November, as the country reported about a hundred outbreaks. The UK has also had four cases of avian flu jumping to humans (most recently, from a man who kept ducks inside his house), but those were different strains.
This is the first time the H3N8 influenza strain has jumped from animals to humans. Unfortunately, it’s unlikely to be the last.