New insights on the emergence of cholera in Latin America during 1991: thePeruvian experience

After a century of absence, in late January 1991, Vibrio cholerae invaded t he Western Hemisphere by way of Peru. Although a number of theories have be en proposed, it is still not understood how that invasion took place. We re viewed the clinical records of persons attending hospital emergency departm ents in the major coastal cities of Peru from September through January of 1989/1990 and 1990/1991. We identified seven adults suffering from severe, watery diarrhea compatible with a clinical diagnosis of cholera during the four months preceding the cholera outbreak, but none during the previous ye ar. The patients were scattered among five coastal cities along a 1,000 km coastline. We postulate that cholera vibrios, autochthonous to the aquatic environment, were present in multiple coastal locations, and resulted from environmental conditions that existed during an El Nine phenomenon. Once in troduced into the coastal communities in concentrations large enough for hu man infection to occur, cholera spread by the well-known means of contamina ted water and food.