LOS ANGELES — Bird flu was in decline, but health officials warned Monday that it appears to be on the rise again.
The United Nations’ Food and Agriculture Organization “urged heightened readiness and surveillance against a possible major resurgence” of the virus, which has crossed over from birds to kill 331 people since its appearance in 2003.
At its peak in 2006, avian flu was present in 63 countries. Just two years later, it was gone from most, and cases of illness in humans dipped to just 302 in 2008. But almost 800 cases of bird flu were recorded in people during the last flu season.
The cause of its reappearance? Birds’ migrations, boosted by poultry farming practices, the FAO said.
Also cause for concern: A new mutant strain of the virus, resistant to vaccines and known as H5N1 2.3.2.1, has been detected in China and in Vietnam.
