Avian flu
Despite the death or destruction of around 150 million birds, the avian flu (H5N1) virus has become endemic in parts of Asia. During the most recent outbreak 130 people have contracted the disease, of which 67 have died - 42 in Vietnam (WHO Nov 2005). People who work closely with poultry - farmers and market workers - are particularly at risk. There is serious concern that H5N1 will mutate into a form that can easily be transmitted between humans causing a global flu pandemic.