EPIDEMIC CHOLERA IN ECUADOR - MULTIDRUG-RESISTANCE AND TRANSMISSION BY WATER AND SEAFOOD

To determine risk factors for cholera in an epidemic-disease area in S outh America, a case-control investigation was performed in Guayaquil, Ecuador, in July 1991. Residents > 5 years old who were hospitalized for treatment of acute, watery diarrhoea and two matched controls for each were interviewed regarding sources of water and food, and eating, drinking, and hygienic habits. Interviewers inspected homes of case-p atients and controls to document water treatment, food-handling, and h ygienic practices. Faecal specimens and shellfish were cultured for Vi brio cholerae 0 1. Isolates were tested for susceptibility to a variet y of antimicrobial agents. Drinking unboiled water (odds ratio [OR] = 4.0, confidence interval [CI] = 1.8-7 5), drinking a beverage from a s treet vendor (OR = 2.8, CI = 1.3-5.9), eating raw seafood (OR = 3.4, C I = 1.4-11.5), and eating cooked crab (OR = 5.1, CI = 1.4-19.2) were a ssociated with illness. Always boiling drinking water at home (OR = 0. 5, CI = 0.2-0.9) was protective against illness. The presence of soap in either the kitchen (OR = 0.3, CI = 0.2-0.8) or bathroom (OR = 0.4, CI = 0.2-0.9) at home was also protective. V. cholerae 0 1 was recover ed from a pooled sample of a bivalve mollusc and from 68% of stool sam ples from case-patients. Thirty-six percent of the isolates from stool specimens were resistant to multiple antimicrobial agents. Specific p revention measures may prevent transmission through these vehicles in the future. The appearance of antimicrobial resistance suggests the ne ed for changes in current methods of prevention and treatment.