UN warns of possible bird flu resurgence

The United Nations warned Monday of a possible resurgence of the deadly bird flu virus, saying wild bird migrations had brought it back to previously virus-free countries and that a mutant strain was spreading in Asia, The Associated Press reported.

A mutant strain of H5N1, which can apparently sidestep defenses of existing vaccines, is spreading in China and Vietnam, the U.N. Food and Agriculture Organization said in a statement Monday. It urged greater surveillance to ensure that any outbreaks are contained.

Vietnam suspended its springtime poultry vaccination this year, FAO said. Most of the northern and central parts of the country where the virus is endemic have been invaded by the new strain.

Elsewhere, FAO says bird migrations over the past two years have brought H5N1 to countries that had been virus-free for several years, including Israel, the Palestinian territories, Bulgaria, Romania, Nepal and Mongolia.