The largest cholera vaccination campaign in history has been launched in an attempt to put the brakes on a disease which is ravaging parts of Africa.

Nearly three and a half million doses of oral cholera vaccine will be used in campaigns in Nigeria, Malawi, Zambia, Uganda and South Sudan.

There have been an increasing number of outbreaks of the infectious disease in recent years and at least 12 countries or areas in sub-Saharan Africa are currently reporting cholera outbreaks.

The disease causes severe diarrhoea and is contracted through eating or drinking contaminated food or water.