||In 1994 and 1996 Guinea-Bissau was affected by large cholera epidemics. During these epidemics, matched case-referent studies were performed to define risk and protective factors for cholera disease in the capital Bissau, where the majority of cases were registered. Based on the results of these studies laboratory experiments were further conducted to study the effect of lime-juice on survival of Vibrio cholerae. These experiments took into account information from a household-survey on storage and handling of water carried out in a randomly selected sample in three districts in Bissau where the Bandim Health Project (BHP) has a demographic surveillance system. As
soon as the epidemic ended in 1994, a population-based survey on retrospectively reported diarrhoea and cholera episodes was conducted to study the patterns of cholera illness and the importance of socio-economic conditions.
We found an association between disease and the source of drinking water and type of storage in the household. Drinking well water, storage of water in open containers, and drinking boiled water increased the risk, while drinking water from stand-pipe was associated with protection. Consumption of tomato sauce and curdled milk was associated with decreased risk of disease, as well as eating with the hand from the same bowl, while washing hands before the meal was protective. Socio-economic status, characterised by house and household conditions and ownership of electrical appliances, was inversely associated with cholera illness. The protective effect of lime-juice observed in the epidemiological studies was confirmed by the laboratory experiment, where V. cholerae did not survive in meal or water treated with lime-juice.
Cholera illness in the three districts was predominant in adults specially in females, the risk increasing with age. Among young children, boys were more affected than girls. Among the ethnic groups, Pepeis and Manjacos were more affected than Fulas and Mandingas.
Results of the studies were and are used in the campaigns for cholera prevention, the use of lime-juice for water treatment and in food being promoted.