Head of WHO flu program says cows outside US could contract bird flu.

The U.S. confirmed the presence of the bird flu in American cow herds. The W.H.O. said there is risk of the disease spreading to other countries.

Head of WHO flu program says cows outside US could contract bird flu.

According to a World Health Organization official, there is a chance that migrating birds could carry the H5N1 bird flu virus and infect cows in nations other than the US.

Following the discovery of the H5N1 virus in 34 dairy cattle herds in nine states since late March, as well as in one individual in Texas, American authorities are attempting to establish the safety of milk and meat.

"With the virus carried around the world by migratory birds, certainly there is a risk for cows in other countries to be getting infected," said Wenqing Zhang, head of WHO's Global Influenza Programme at a news briefing in Geneva.

She reiterated that the U.N. agency deems the overall public health risk posed by the virus to be low but urged vigilance.

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.