Experts have been concerned at the rising number of bird flu cases among humans in China, and have warned the strain could be more infectious for humans.
Five people – four men and one woman – in Sichuan province, Zhejiang province, and the Guangxi Autonomous Region were infected with the bird flu strain in 2021, The Sun reported, citing the Hong Kong health department.
Two of those people have now died, with the other three currently in hospital fighting for their lives, officials said in a statement.
Four out of five of the infected people were exposed to live domestic poultry, the statement said. How the fifth was exposed is being investigated.
China has reported two deaths from avian flu after confirming five new cases of H5N6, with the World Health Organisation calling for ‘urgent’ action. Pictured: Chickens cages in China (file photo)
The first person to die from H5N6 in December was a 75-year-old man from Luzhou, Sichuan. He was infected on December 1, rushed to hospital on December 4 and passed away on December 12.
The second victim was a 54-year-old man from Leshan, Sichuan, who was infected on December 8, admitted on December 16 and died on December 24.
A 51-year-old woman from Hangzhou, Zhejiang fell ill on December 15 and was taken to hospital three days later. In the statement, her condition was listed as critical.
Two other men from Liuzhou, Guangxi – a 53-year-old and a 28-year-old – were also infected and rushed to hospital on December 23. The older man’s condition is listed as serious, while the condition of the younger man is also critical.
‘While local surveillance, prevention and control measures are in place, the CHP will remain vigilant and work closely with the World Health Organization and relevant health authorities to monitor the latest developments,’ the statement said.
A total of 63 human cases of avian influenza A (H5N6) have been reported in China since 2014. More than half of those were reported in the last six months.
Though the numbers are much lower than the hundreds infected with H7N9 in 2017, the infections are serious, leaving many critically ill.
Most of the cases had come into contact with poultry, and there are no confirmed cases of human-to-human transmission, the WHO said in October.
It said further investigation was ‘urgently’ required to understand the risk and the increase in spill over 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, said last year.
Pictured: Workers vaccinate chicks (file photo). China vaccinates poultry against avian influenza but the vaccine used last year may only partially protect against emerging viruses, preventing large outbreaks but allowing the virus to keep circulating
‘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.’
China is the world’s biggest poultry producer and top producer of ducks, which act as a reservoir for flu viruses.
Backyard farms in China are common and many people still prefer to buy live chickens at markets.
China vaccinates poultry against avian influenza but the vaccine used last year may only partially protect against emerging viruses, preventing large outbreaks but allowing the virus to keep circulating.
There have been fewer than 1,000 cases globally since the virus emerged in the late 1990s. Human-to-human spread is even rarer.
But because of how viruses evolve, experts are concerned a bird flu strain could mutate into one that could spread easily between humans and cause a pandemic.
In November, health authorities in the UK issued a warning to people travelling to China about the risks posed by bird flu.
A virus that kills up to 50% of humans… but transmission is rare: Everything you need to know about bird flu
What is bird flu?
Bird flu, or avian flu, is an infectious type of influenza that spreads among bird species but can, on rare occasions, jump to human beings.
Like human influenza there are many strains of bird flu:
The current outbreak in birds in the UK is H5N1, the strain that the infected Briton has.
Where has it been spotted in the UK?
A case of bird flu has been spotted in a human in the South West of England.
Officials did not disclose the exact location of the case, but UKHSA said all close personal contacts of the individual have been traced and there is ‘no evidence’ of the infection having spread to anyone else.
The UK is facing a particularly bad year for cases in birds, with around one million having to be culled in Lincolnshire — where the virus was first spotted on December 11.
Exclusion sites were put around Mablethorpe, Alford and South Elkington in the region.
There have also been outbreaks North Yorkshire and Pocklington in East Yorkshire.
How deadly is the virus?
Fatality rates for bird flu in humans have been estimated to be as high as 50 per cent.
But because transmission to humans is so rare, fewer than 500 bird flu deaths have been reported to the World Health Organization since 1997.
Paul Wigley, professor of avian infection and immunity at the University of Liverpool, said: ‘The advice given by APHA and UKHSA over contact with infected birds is sensible and should be followed.
‘The risk of wider infection in the general public remains low.’
Is it transmissible from birds to humans?
Cases of bird-to-human transmission are rare and usually do not spread on human-to-human.
Bird flu is spread by close contact with an infected bird or the body of one.
This can include:
- touching infected birds
- touching droppings or bedding
- killing or preparing infected poultry for cooking
Professor Ian Jones, a virologist at the University of Reading, said: ‘Transfer of avian flu to people is rare as it requires direct contact between an infected, usually dead, bird and the individual concerned.
‘It is a risk for the handlers who are charged with the disposal of carcasses after an outbreak but the virus does not spread generally and poses little threat.
‘It does not behave like the seasonal flu we are used to.
‘Despite the current heightened concern around viruses there is no risk to chicken meat or eggs and no need for public alarm.’
What are the symptoms?
Symptoms of bird flue usually take three to five days to appear with the most common being:
- a very high temperature
- or feeling hot or shivery
- aching muscles
- a cough or shortness of breath