The clinico-epidemiological characteristics of cholera patients in Mexico City

To compare the clinical and epidemiological characteristics of cholera patients and patients with diarrhea of different etiology (controls), treated at Mexican Institute of Social Security medical units in northeast Mexico City, from 1995 to 1998. Cross-sectional analytical study design. Data were collected using the official form "Immediate Notification of Cholera Cases" that each medical unit reports to the Coordination of Community Health. Statistical analysis consisted of comparisons of means and proportions between both groups. In 4,952 notifications, there were 588 cholera cases and 4,364 controls. The age range of cases was 39 to 51 years and 54% were females. During 1995 and 1997 (years with higher proportion of cases) patients with cholera had a greater frequency of watery evacuations than controls (97% vs. 73%), "rice water" appearance (31% vs. 13%), vomiting (72% vs. 63%), muscular spasms (49% vs. 26%), dehydration (83% vs. 71%), hypovolemic shock (10% vs. 1%) and death (0.85% vs. 0.25%). These differences were statistically significant. Cholera presents a biannual cyclic behavior; greater frequencies are associated with greater severity and complications. It is necessary to increase epidemiologic surveillance and medical efforts for opportune diagnosis and treatment.