What is bird flu? 11-year-old girl in Cambodia dies from virus

Health agencies are modelling potential human-transmission scenarios for the H5N1 virus based on the Covid pandemic and the 1918 influenza outbreak

A closed road leading to a chicken farm is seen after an outbreak of bird flu in the village of Upham in southern England February 3, 2015. 10,000 chickens are to be slaughtered at the farm following the outbreak of the H7 strain of avian influenza, local media reported. REUTERS/Peter Nicholls (REUTERS - Tags: ANIMALS FOOD ENVIRONMENT)
Bird flu has spread rapidly across Europe in the most recent outbreak among poultry. (Reuters)

An 11-year-old girl has died from bird flu in Cambodia, after contracting the first known human case of the H5N1 virus in the country since 2014.

The girl became ill on 16 February and died on Wednesday, according to the country's health ministry. Her father has since been confirmed to have contracted the virus and 11 other people who came into contact with the child are being tested.

The case has put other countries on high alert for human cases of the virus, which has resulted in the deaths or culling of more than 200 million birds around the world.

Although the virus has spread rapidly among the UK's avian population, the UK Health Security Agency (UKHSA) has said there is "no evidence so far that the virus is getting better at infecting humans or other mammals".

What is bird flu?

Avian influenza, otherwise known as bird flu, is categorised as influenza A H5N1. The virus has spread widely in birds around the world since 2021 but has thus far resulted in very few infections in humans.

According to the European Centre of Disease Control the virus is a "highly pathogenic avian influenza virus", meaning it has a high mortality rate among infected poultry.

The 2021/2022 epidemic has been among the worst recorded in Europe, and the UKHSA is currently looking into potential response scenarios should the virus begin to transmit to humans more widely.

The agency is currently assessing whether the lateral flow devices used to detect COVID could be used to test for the H5N1 virus in humans, and has been monitoring people who have come into contact with infected birds.

Arturo Casadevall, the chair of the Department of Molecular Microbiology and Immunology at Johns Hopkins University in the US, which supplied widely used coronavirus tracking data, said information on whether the 12 suspected new infections in Cambodia would be key.

The UKHSA is currently modelling several different potential scenarios of human transmission - one based on the recent coronavirus pandemic, and one based on the 1918 flu outbreak, whose fatality rate was higher.

In a potential scenario with a higher fatality rate, people could see "significant behavioural differences relative to the recent pandemic experience", UKHSA said.

Dr Meera Chand, incident director for avian influenza at UKHSA, said: "The latest evidence suggests that the avian influenza viruses we’re seeing circulating in birds do not currently spread easily to people.

"However, viruses constantly evolve, and we remain vigilant for any evidence of changing risk to the population, as well as working with partners to address gaps in the scientific evidence."