Estudio seroepidemiológico del cólera en Colombia

Abstract

The vibriocidal test has been widely used to confirm clinical cases of cholera, to measure immunogenicity of possible vaccines and asan epidemiological tool to study diseases in endemic areas as well as in outbreaks. In March 1991, Colombia was affected by the first cholera epidemic in this century. The aim of this study was therefore to obtain additional information concerning the magnitude of epidemics in our country using a serological test. Vibriocidal antibodies were measured; using micromethodology, on Vibrio cholerae 01, El Tor lnaba and El Tor Ogawa strains. A reactive result was defined as that obtained from titres greater or equal to 80 and recent infection was established if a titre was greater than or equal to 640. Serum samples were studied from 73 patients with diarrhoea and from 4,577 patients who had consulted regional hospitals for other reasons. The samples were obtained from 5 of those 6 rural areas affected by the epidemics; 1,520 were obtained in 1991, 1,229 in 1992 and 1,901 in 1993. Overall reactivity was 21.5%; 25% in 1991, 21.4% in 1992 and 19% in 1993. Regarding gender, reactivity was 24% in males and 20% in females; no age group differences were encountered. Recent infection was determined in 10% of the cases. In cholera patients, infection prevalence (determined by serum reactivity) was 68.5% and recent infection prevalence was 51 %. Vibriocidal results from the Pacificand Atlantic regions showed a very high correlation with clinical cholera cases' epidemiological evolution.