There is a risk that the H5N1 bird flu virus, present in many wild birds, may infect cows in countries beyond the United States as they migrate, a World Health Organization official said on Tuesday.
US officials are seeking to verify the safety of milk and meat after confirming the H5N1 virus in 34 dairy cattle herds in nine states since late March, and in one person in Texas.
“With the virus carried around the world by migratory birds, certainly there is a risk for cows in other countries to be getting infected,” Wenqing Zhang, head of WHO’s Global Influenza Programme, said at a news briefing in Geneva.
The virus is widespread among wild birds in the United States and sometimes infects poultry and even outdoor cats, but up until now, has been rare in cows.
Zhang reiterated that the U.N. agency deems the overall public health risk posed by the virus to be low but urged vigilance, especially among farm workers.
While the virus is not thought to be able to spread through milk, Zhang repeated long-standing WHO advice to only consume pasteurised milk.
Asked to evaluate U.S. transparency on the outbreak so far, Zhang said the global body had received regular updates and praised a decision to share the virus’ genetic sequence early.
“I do think the collaboration with U.S. CDC (Centers for Disease Control and Prevention) and the information we’ve received so far enables us to monitor the situation and to update the preparedness measures,” she said.