China reports first human case of H10N3 bird flu

China reported the world's first human infection of the H10N3 bird flu strain on Tuesday but said the risk of it spreading widely among people was very low.

A 41-year-old man, a resident of Zhenjiang City in China's eastern province of Jiangsu, was hospitalized on April 28 after developing a fever and other symptoms, the National Health Commission said in a statement.

The Chinese Center for Disease Control and Prevention carried out whole-genome sequencing of the specimen on May 28 and the result was positive for the H10N3 virus.

The man was stable and ready to be discharged from hospital. All close contacts of the patient in Jiangsu have been placed under medical observation and emergency monitoring has been initiated, said the NHC, adding that nothing abnormal has been detected.

The commission did not give details on how the man had been infected with the virus.

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

The strain is "not a very common virus," said Filip Claes, regional laboratory coordinator of the Food and Agriculture Organization's Emergency Center for Transboundary Animal Diseases at the Regional Office for Asia and the Pacific.

Only around 160 isolates of the virus were reported in the 40 years to 2018, mostly in wild birds or waterfowl in Asia and some limited parts of North America, and none had been detected in chickens so far, he added.

Analyzing the genetic data of the virus will be necessary to determine whether it resembles older viruses or if it is a novel mix of different viruses, Claes said.

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 around 300 people during 2016-17. No other cases of human infection with H10N3 have previously been reported globally, the NHC said.

Following recent avian flu outbreaks in Africa and Eurasia, the head of China's Center for Disease Control and Prevention last week urged stricter surveillance in poultry farms, markets and wild birds.

Hong Kong's food safety authority decided on Monday to suspend the import of poultry meat and products from the German state of Bremen in view of an outbreak of highly pathogenic H5N8 avian influenza there.

 It suspended poultry import from bird flu-affected areas in Poland last week based on a notification about H5N8 avian influenza outbreaks in Makowski District of Mazowieckie Region and Bialski District of Lubelskie Region in Poland.