The cholera epidemic in Ecuador: towards an endemic in Latin America

We present an epidemiological study of the first wave of cholera in Ecuador in 1991. One month after the 7th cholera pandemic hit the Pacific coast of Peru, the disease reached the coast of Ecuador and spread to the rest of the country within a few weeks. One year later, 46,320 cases have been notified, giving an incidence of 481 cases per 100,000 inhabitants. The overall mortality rate has been low (697 deaths, i.e. 1.50%), although there have been large differences between the various provinces: in the Andes (Sierra), for example, rates above 8% have been recorded. The first wave peaked about eight weeks after the first case, with 3400 new cases per week throughout the country. This was followed by a gradual decrease towards a baseline of 250-500 new cases per week. A resurgence was observed in most coastal and Andean provinces from November 1991 onwards. The kinetics of the epidemic are compatible with an endemic implantation of the disease in Ecuador, as is probably the case in the entire intertropical Pacific coast region of Latin America. From the data presented, the latin-american episode of the 7th pandemic starting on the Pacific coast, is characterized by a very high attack rate and a low mortality rate as compared to Africa, and the unexpected involvement of populations living on the high Andean plateaux. It is probable from the results collected in Ecuador that cholera will become endemic in Latin America.