A World Health Organization official on Thursday called for stronger surveillance in animals for evidence of infection with H5N1 bird flu in order to curb its spread. The official also urged stronger efforts to reduce the risk of transmission of the virus to new species of animals and to humans.

WHO along with the partnership of World Organization for Animal Health and Food and Agriculture Organization has decided to step up the surveillance of H5N1 virus after a human case was reported in the US earlier this month.

Small but growing number of H5N1 avian influenza infections have been detected in humans around the world in recent years