WHO alarmed over rising bird flu cases

The World Health Organization said the rising number of bird flu cases has raised "great concern "because it had an "extremely high "mortality rate among those who had been infected around the world.

The WHO's data showed that from 2003 through March 2024, a total of 889 worldwide human cases of H5N1 infection had been recorded in 23 countries, resulting in 463 deaths and a 52 percent mortality rate. The majority of deaths occurred in Southeast Asian countries and Egypt.

The most recent death was in Vietnam in late March, when a 21-year-old male without underlying conditions died of the infection after bird hunting. So far, cases in Europe and the United States have been mild.

Jeremy Farrar, the chief scientist at the WHO, said H5N1, which predominantly started in poultry and ducks, "has spread effectively over the course of the last one or two years to become a global zoonotic — animal — pandemic".

He said the great concern is that the virus is increasingly infecting mammals and then develops the ability to infect humans. It would become critical if the virus develops the ability to "go from human-to-human transmission", Farrar said.

In the past month, health officials have detected H5N1 in cows and goats from 29 dairy herds across eight states in the US, saying it is an alarming development because those livestock were not considered susceptible to H5N1.

The development worries health experts and officials because humans regularly come into contact with livestock on farms. In the US, there are only two recorded cases of human infection — one in 2022 and one in April this year in Texas. Both infected individuals worked in close proximity to livestock, but their symptoms were mild.

Zhang Wenqing, head of the WHO's global influenza program, told the Daily Mail that "bird-to-cow, cow-to-cow and cow-to-bird transmissions have also been registered during these current outbreaks, which suggest that the virus may have found other routes of transition than we previously understood".

Zhang said multiple herds of cow infections in US states meant "a further step of the virus spillover to mammals".

The virus has been found in raw milk, but the Texas Health Services department said the cattle infections do not present a concern for the commercial milk supply, as dairies are required to destroy milk from sick cows. In addition, pasteurization also kills the virus.

Darin Detwiler, a former food safety adviser to the Food and Drug Administration and the US Agriculture Department, said people in the US should avoid rare meat and runny eggs.

Agencies contributed to this story.