China Reports the World’s First Human Infection of H10N3 Bird Flu

A man in eastern China is the first human on record to contract a strain of bird flu known as H10N3, according to health authorities.

The 41-year-old in Jiangsu province developed a fever on April 23, and was hospitalized after the condition worsened five days later, the National Health Commission said in an online statement on Tuesday. 

On May 28, the man tested positive for H10N3, a subtype of Influenza A virus, which causes flu in birds. 

The man is in a stable condition and largely ready for discharge, the health authority said. His close contacts have been put under medical surveillance, but no abnormalities have been detected, according to the statement. 

It said H10N3 is low pathogenic, meaning it causes less severe diseases in poultry. “This infection came from a sporadic transmission from poultry to a human,” the statement said. “The risk of large-scale transmissions is extremely low.” 

The World Health Organization said while the source of the patient’s exposure to the H10N3 virus is unknown, there is no indication the virus can spread between humans. The Chinese government did not say whether the patient was in close contact with poultry.

“As long as avian influenza viruses circulate in poultry, sporadic infection of avian influenza in humans is not surprising, which is a vivid reminder that the threat of an influenza pandemic is persistent,” the WHO said in a statement on Wednesday.

The WHO does not recommend any travel restrictions or special screening at points of entry regarding the H10N3 virus.

Siddharth Sridhar, a virologist with the University of Hong Kong, agrees that people do not need to worry too much at this stage, although authorities should conduct close surveillance to detect potential signs of human-to-human transmission. 

“The types of influenza that circulate in birds are very different from the ones that normally circulate in humans. But what occasionally happens is you have interfaces where humans are in close contact with poultry, because of such intense exposure, you may have poultry to human transmission,” he told VICE World News. “At one level it’s completely expected and predictable that this will happen occasionally.” 

In response to the case, the Hong Kong government has asked travelers to mainland China to avoid visiting wet markets, live poultry markets or farms. Travelers are also advised to avoid purchasing live or freshly slaughtered poultry. 

Influenza A viruses are divided into subtypes based on two proteins on their surfaces, hemagglutinin (H) and neuraminidase (N). Some types of avian influenza A viruses can infect humans and cause severe diseases. Although the viruses do not easily transmit between humans, they have the potential to mutate and become more contagious, according to the WHO.  

The last major bird flu outbreak took place in China in 2016-17, when more than 750 people were infected by the H5N7 virus and more than 280 died from the disease. 

Sporadic human infections are occasionally reported from around the world. In February, Russia reported the world’s first human infection with H5N8 bird flu, with seven poultry farm workers testing positive for the virus. The cases were asymptomatic. 

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