The H5N1 bird flu virus as seen through a microscope. The deadly H5N1 strain of bird flu has spread to four farms in Nigeria, amid fears that a disease which has already killed more than 80 people in Asia will cause an Africa-wide epidemic
Poultry and poultry products from Nigeria and all poultry imports through the eastern border of Ghana have been banned as part of preventive measures against the deadly bird flu.
