Scientists are warning that the strain of bird flu that killed an 11-year-old girl in Cambodia mutated to better infect humans. The lead researcher of the team that decoded the virus says the finding must be treated with "utmost caution".
Dr Erik Karlsson from the Pasteur Institute of Cambodia told Sky News the virus that infected the girl was different from samples taken from birds. He said there are indications the virus had already passed through a human and evolved before infecting the girl.
The medical science community is on high alert, with health authorities in the UK modelling scenarios for a bird flu pandemic in response to the threat. The Centres for Disease Control and Prevention in the US is ramping up its pandemic preparedness and the saitation has been described as "worrying" by the World Health Organisation (WHO).
The girl, from Prey Veng province, was the first person to be killed by H5N1 this year when she died last month. Her father also tested positive for the virus but did not show symptoms.
Dr Karlsson explained the significance of the virus infecting humans. "Any time these viruses get into a new host they'll have certain changes that allow them to replicate a little bit better or potentially bind to the cells in our respiratory tract a little bit better," he said.
He added that the virus had not fully adapted to humans yet, stating: "It's still a bird virus." Tests showed that the strain caught by the girl was the 2.3.2.1c variant of H5N1. This is endemic in wild birds and poultry in Cambodia but differs from the 2.3.4.4b type which has spread quickly worldwide and started to infect some mammals.
"This was a zoonotic spillover [of a virus infecting a new species] and needs to be treated with the utmost concern," he cautioned. "Something may be happening here in Cambodia and something may be happening on the other side of the world in South America, but we don't really know what could cause the problem tomorrow."
Subscribe here for the latest news where you live
More than 15 million animals have been killed by the virus. And H5N1 has a human mortality rate of more than 50 per cent.
Some 52 per cent of the 873 people known to have had human cases of the avian disease have died, according to the WHO. But there is no evidence, at this stage, that the virus spreads easily between people.
A major factor in this is that bird flu viruses attach themselves to receptors only found in cells deep in human lungs. The virus would most likely have to evolve so that it binds to a receptor found in human nasal passages in order for widespread transmission to occur.
It comes after a bird flu expert warned that we could be "sleepwalking" into disaster, after it was disclosed that 53 per cent of the 860 people known to have had human cases of the avian disease between 2003 and 2023 have died.
For more stories from where you live, visit InYourArea.
