The H5N1 bird flu virus strain has been detected in very high concentrations in raw milk from infected animals, the WHO said Friday, though how long the virus can survive in milk is unknown.

Avian influenza A(H5N1) first emerged in 1996 but since 2020, the number of outbreaks in birds has grown exponentially, alongside an increase in the number of infected mammals. The strain has led to the deaths of tens of millions of poultry, with wild birds and land and marine mammals also infected. Cows and goats joined the list last month—a surprising development for experts because they were not thought to be susceptible to this type of influenza. US authorities earlier this month said a person working on a dairy farm in Texas was recovering from bird flu after being exposed to cattle. ....