Epidemiological model of diarrhoeal diseases and its application in prevention and control.

In this paper, a prototype epidemiological model of acute bacterial and viral diarrhoeal diseases occurring in young children is formulated. The model is able to mimic the observed epidemiological patterns of infantile diarrhoeal diseases associated mainly with enterotoxigenic Escherichia coli or with rotavirus. The proposed mathematical model predicts a plausible pattern of the serological profile of an enteric infection. According to computer simulation experiments (CSE) with this model, it is not necessary to develop an enteric vaccine conferring total and long-lasting immunity in order to achieve protection from diarrhoeal diseases in young children. Given a protective efficacy and a finite duration of vaccine-induced protection, the optimal immunization policy must be sought. Oral rehydration therapy (ORT) intervention has a clear effect in diminishing the number of individuals dying from diarrhoeal illness. The CSE also predict an apparent reduction in age-prevalence of diarrhoeal diseases by use of ORT.