Man, 41, in Jiangsu, diagnosed on 28 May but risk of avian virus spread is low, says state health agency

Chicken carcasses at a wholesale poultry market, Shanghai
Chicken carcasses at a wholesale poultry market in Shanghai. Many strains of avian flu are present in China and some sporadically infect people. Photograph: AP

A 41-year-old man in China’s eastern province of Jiangsu has been confirmed as the first human case of infection with the H10N3 strain of bird flu, although health officials in China said the risk of large-scale spread remained low.

The man, a resident of the city of Zhenjiang, went to hospital on 28 April after developing a fever and other symptoms, China’s national health commission said.

He was diagnosed as having the H10N3 avian influenza virus on 28 May, the commission said though it did not give details about how the man had been infected with the virus. The man was stable and ready to be discharged from hospital. Medical observation of his close contacts had not found any other cases.

H10N3 is a low pathogenic, or relatively less severe, strain of the virus found in poultry, and the risk of it spreading on a large scale is very low, the commission added.

The strain was “not a very common virus”, said Filip Claes, regional laboratory coordinator of the Food and Agriculture Organization’s Emergency Centre for Transboundary Animal Diseases, at the Asia and Pacific regional office. Only about 160 isolates of the virus were reported in the 40 years to 2018, mostly in wild birds or waterfowl in Asia and in some limited areas of North America, and none had been detected in chickens so far, Claes said.

Analysing the genetic data of the virus would be necessary to determine whether it resembled older viruses or if it was a novel mix of different viruses, he added.

Many different strains of avian influenza are present in China and some sporadically infect people, usually those working with poultry. There have been no significant numbers of human infections with bird flu since the H7N9 strain killed about 300 people during 2016-2017.

No other cases of human infection with H10N3 have previously been reported globally, the commission said.