Outbreaks of a deadly bird flu in Asia require tough precautions against the emergence of a new virus strain that could sweep through the human population, the World Health Organization said.

Thailand, the world’s fourth largest chicken exporter last year, has seen avian flu hit 15 of 76 provinces over the last two weeks. Since late last year, China, South Korea, Taiwan, Vietnam, Cambodia and Indonesia also have reported cases.

“While these outbreaks, thus far, remain restricted to poultry populations, they nevertheless increase the chances of virus transmission and human infection,” WHO said in a statement issued late Friday.

The international health agency also warned of the possible emergence of a new virus strain that could spark a “global pandemic.”

Among the precautions WHO urged were protective clothing for workers who might be exposed to the bird flu, which is easily transmitted, and vaccines for those workers.

WHO also urged countries with infected flocks to increase surveillance by local and national health officials and to set up procedures for quick sharing of virus samples.

“Without such virus samples, WHO will not be in a position to provide proper vaccine prototype strains and related guidance for vaccine producers,” the agency warned.