The first human case of a rare strain of bird flu known as H10N3 has been reported in a 41-year-old man in eastern China.
The man is from Jiangsu province, north-west of Shanghai, and was admitted to hospital on 28 April. He is in a stable condition, China’s National Health Commission said.
Until now, no human case of H10N3 has been reported elsewhere, and the risk of large-scale spread among people is low, the commission said.
Bird flu, or avian flu, is caused by influenza viruses that spread between birds. It can often spread easily between birds, but very rarely causes disease in humans.
Symptoms resemble those of normal flu – fever, cough, muscle aches, sore throat – but it can develop into a serious respiratory illness.
Other strains of bird flu, including H5N1 and H7N9, have caused hundreds of deaths in humans since the first cases were reported in 1997.
“Mostly these infections are by those in very close contact with infected birds, poultry or ducks with direct exposure whilst handling them or in preparation of meat from the infected animal. Once cooked, infected meat poses a very low threat,” says John McCauley at the Francis Crick Institute in London.
“Most avian influenza viruses aren’t transmitted easily between humans. This is because they are adapted to spread well between birds,” says Nicole Robb at the University of Warwick, UK. “The good news is that the H10N3 bird flu virus is an ‘H10’ virus, or ‘low pathogenic subtype’, meaning that it causes few signs of disease in birds and that these viruses also very rarely cause serious disease in humans.”
“Viruses of the H5 or H7 subtype are more worrying as low pathogenic versions can infect poultry and evolve into highly pathogenic strains, which cause fatal disease in birds and can cause serious illness in humans in the rare cases that humans have been infected,” she says.
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