Rise in Human Bird Flu Cases in China Shows Risk of Fast-Changing Variants: Health Experts

BEIJING—A leap successful the fig of radical successful China infected with bird flu this twelvemonth is raising interest among experts, who accidental a antecedently circulating strain appears to person changed and whitethorn beryllium much infectious to people.

China has reported 21 quality infections with the H5N6 subtype of avian influenza successful 2021 to the World Health Organization (WHO), compared with lone 5 past year, it said.

Though the numbers are overmuch little than the hundreds infected with H7N9 successful 2017, the infections are serious, leaving galore critically ill, and astatine slightest six dead.

“The summation successful quality cases successful China this twelvemonth is of concern. It’s a microorganism that causes precocious mortality,” said Thijs Kuiken, prof of comparative pathology astatine Erasmus University Medical Centre successful Rotterdam.

Most of the cases had travel into interaction with poultry, and determination are nary confirmed cases of human-to-human transmission, said the WHO, which highlighted the emergence successful cases successful a connection connected Oct. 4.

It said further probe was “urgently” required to recognize the hazard and the summation successful spillover to people.

Since then, a 60-year-old pistillate successful Hunan state was admitted to infirmary successful a captious information with H5N6 influenza connected Oct. 13, according to a Hong Kong authorities statement.

While quality H5N6 cases person been reported, China has reported nary outbreaks of H5N6 successful poultry since February 2020.

China is the world’s biggest poultry shaper and apical shaper of ducks, which enactment arsenic a reservoir for flu viruses.

The Chinese Center for Disease Control and Prevention (CDC) could not beryllium reached for remark connected the emergence successful H5N6 quality cases. However, a survey published connected its website past period said the “increasing familial diverseness and geographical organisation of H5N6 airs a superior menace to the poultry manufacture and quality health”.

Workers vaccinate chicks with the H9 vertebrate flu vaccine astatine a workplace successful Changfeng county, Anhui province, China, connected April 14, 2013. (Stringer/Reuters)

Avian influenza viruses perpetually circulate successful home and chaotic birds, but seldom infect people. However, the improvement of the viruses, which person accrued arsenic poultry populations grow, is simply a large interest due to the fact that they could alteration into a microorganism that spreads easy betwixt radical and origin a pandemic.

The largest fig of H5N6 infections person been successful southwestern Sichuan province, though cases person besides been reported successful neighboring Chongqing and Guangxi, arsenic good arsenic Guangdong, Anhui, and Hunan provinces.

At slightest 10 were caused by viruses genetically precise akin to the H5N8 microorganism that ravaged poultry farms crossed Europe past wintertime and besides killed chaotic birds successful China. That suggests the latest H5N6 infections successful China whitethorn beryllium a caller variant.

“It could beryllium that this variant is simply a small much infectious (to people)…or determination could beryllium much of this microorganism successful poultry astatine the infinitesimal and that’s wherefore much radical are getting infected,” said Kuiken.

Four of the Sichuan cases raised poultry astatine location and had been successful interaction with dormant birds, said a September study by China’s CDC. Another had bought a duck from a unrecorded poultry marketplace a week earlier processing symptoms.

China vaccinates poultry against avian influenza but the vaccine utilized past twelvemonth whitethorn lone partially support against emerging viruses, preventing ample outbreaks but allowing the microorganism to support circulating, said Filip Claes, Regional Laboratory Coordinator astatine the Emergency Centre for Transboundary Animal Diseases astatine the Food and Agriculture Organization.

The Ministry of Agriculture and Rural Affairs did not respond to a petition for comment.

Backyard farms successful China are communal and galore radical inactive similar to bargain unrecorded chickens astatine markets.

Guilin metropolis successful Guangxi region, which had 2 quality cases successful August, said past period it had suspended trading of unrecorded poultry successful 13 municipality markets and would abolish the commercialized wrong a year.

By Dominique Patton