There is growing concern about a lethal strain of bird flu in humans as more cases appear in China.
The health authority in the southern Chinese province of Guangdong says one case of a human being infected with the H5N6 strain of bird flu has been reported in the city of Dongguan.
The deadly strain – which has a fatality rate of nearly 50 per cent, according to some reports – has infected a growing number of humans despite global health authorities initially thinking the risk to humans was very low.
This strain was first detected in 2014 but half of the some 48 known cases in humans have been recorded this year.
The jump in the number of people in China infected with bird flu this year is raising concern among experts, who say a previously circulating strain appears to have changed and may be more infectious to people.
China has reported 21 human infections with the H5N6 subtype of avian influenza in 2021 to the World Health Organisation (WHO), compared with only five last year.
Though the numbers are much lower than the hundreds infected with H7N9 in 2017, the infections are serious, leaving many critically ill, and at least six dead.
Earlier this year the WHO called on China to increase surveillance of the deadly bird flu.
But the latest cases are only heightening anxieties.
"The increase in human cases in China this year is of concern. It's a virus that causes high mortality," said Thijs Kuiken, professor of comparative pathology at Erasmus University Medical Centre in Rotterdam.
H5N6 'a serious threat to human health'
Most of the cases had come into contact with poultry, and there are no confirmed cases of human-to-human transmission, said the WHO, which highlighted the rise in cases in a statement earlier this month.
However one recent case, a woman in her 60s who has hospitalised in July, said she had no contact with poultry ahead of her illness, The Telegraph in Britain reported.
The WHO said further investigation was "urgently" required to understand the risk and the increase in spill over to people.
The Chinese Centre for Disease Control and Prevention (CDC) published a study on its website last month, saying the "increasing genetic diversity and geographical distribution of H5N6 pose a serious threat to the poultry industry and human health".
China is the world's biggest poultry producer and top producer of ducks, which act as a reservoir for flu viruses.
Avian influenza viruses constantly circulate in domestic and wild birds, but rarely infect people. However, the evolution of the viruses, which have increased as poultry populations grow, is a major concern because they could change into a virus that spreads easily between people and cause a pandemic.
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