China has reported 21 cases of humans infected with the H5N6 strain of bird flu this year, according to the World Health Organization (WHO). Last year there were only five cases. Of the 21 people, many were critically ill, and at least six died.
Experts are concerned about the jump in numbers and think the strain might have changed, and could be more infectious to people.
“The increase in human cases in China this year is of concern. It’s a virus that causes high mortality,” Thijs Kuiken, professor of comparative pathology at Erasmus University Medical Centre in Rotterdam, told Reuters.
Last month, the Chinese Center for Disease Control and Prevention (CDC) said on their website that the “increasing genetic diversity and geographical distribution of H5N6 pose a serious threat to the poultry [chicken, ducks] industry and human health”.
Bird flu, also known as avian flu or avian influenza, constantly circulates at chicken, duck, turkey and geese farms and wild birds. The virus rarely affects people.
But as chicken, duck, turkey and geese farms have grown immensely in recent years, the virus could evolve and change into a virus that spreads easily between people, experts say.
Chicken and duck factories
China is the world’s biggest chicken producer and top producer of ducks. The factories where the animals are kept act as a reservoir for bird flu viruses.
In 2019, China slaughtered 9.3 billion chickens, including 4.4 billion white-feathered broilers, popular with fast-food chains for cheap, plump meat.
Most H5N6 infections were in Sichuan province; some cases were reported in neighbouring Chongqing, Guangxi, Guangdong, Anhui and Hunan provinces.
“It could be that this variant is a little more infectious (to people)…or there could be more of this virus in poultry at the moment, and that’s why more people are getting infected,” said Kuiken.
The WHO said further investigation was “urgently” required to understand the risk and the increase in spillover to people.
Live animal markets
A report by the CDC said that four people in the Sichuan cases raised animals at home, so-called backyard farms.
In another case, a person had bought a duck from a live animal market a week before developing symptoms. Some people in China still prefer to buy live chickens or ducks at markets.
After reporting two human cases of H5N6 bird flu, Guilin city in the Guangxi region said it had suspended trading of live chickens in 13 markets and would end the trade within a year.
Millions of animals killed
This year, countries in Europe, Asia and Africa have had bird flu outbreaks. So far, the only solution governments have when bird flu is detected at a farm is to kill all animals around the infected animals. This sometimes results in mass killings.
Last winter, France killed around 3 million birds after a bird flu outbreak in its southwestern duck-breeding region. Last week, 25,000 turkeys were killed in Israel. Bulgaria killed more than 250,000 ducks and chickens in February.
Animal rights activists have long asked to reconsider the bird farming industry to prevent emerging diseases and for animal welfare reasons.
This year, other strains of bird flu have also jumped to humans. An 11-year-old boy died from the H5N1 strain of bird flu in India in July. In June, a 41-year-old man in China was infected with the H10N3 strain of bird flu. And in February, Russian scientists said they’d detected the H5N8 strain of bird flu in humans.
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