More than 45,000 hens have been slaughtered, burnt, and buried in southern Mozambique to prevent the spread of bird flu, officials say. The birds had been imported from neighboring South Africa, which has been hit by an outbreak of the disease. The outbreak has now spread to Mozambique's district of Morrumbene in the southern Inhambane province. Authorities are trying to contain it as fears grow that it could spread to other parts of the country. Bird flu is an infectious disease of poultry and wild birds. It can spread through entire flocks of domestic birds within a matter of days, through bird droppings and saliva, or through contaminated feed and water. The outbreak has led to a shortage of eggs and chickens, and a sharp rise in prices in recent days, in Mozambique, including in the capital Maputo. The average price of chicken has nearly doubled from 350 Mozambican metical ($5; £4) to 600, while the price of a dozen eggs has shot up from 100 to 150 metical.