Epidemiology of acute diarrhoea in a rural medical care system in México (IMSS-COPLAMAR).

This paper shows the results of a study of acute diarrhoea (AD) in 137 rural communities in Mexico. We studied 51 communities with 1000 inhabitants or less, 45 communities with 1001 to 5000 inhabitants and, 41 with 5001 to 15000 inhabitants. All in all we observed 4,796.9 persons year during a period comprised from March 1982 to February 1983. In communities with more than 5000 inhabitants there occurred 0.85 episodes of AD per person-year, whereas in the smaller ones the incidence was only 0.58 episodes per person-year p less than 0.01). In small communities the frequency was higher in families with poor water supply and inadequate excreta disposal, whereas in large communities the frequency was not affected by such services. In 95.6 percent of the cases the episodes were self-limited within the first 14 days. There were seven deaths, five occurring in children under one year of age, six in children living in small communities and, five associated with dehydration. These results suggest that the size of the community constitutes a risk factor for AD in rural areas, which deserves to be explored in further studies. The lethality observed in small communities stresses the need of programs for better treatment of this frequent disease.