A common-source water-borne outbreak of multidrug-resistant typhoid fever in a rural Thai community.

We report an epidemiological investigation of an explosive water-borne outbreak caused by multidrug-resistant (MDR) Salmonella Typhi in a non-endemic community with otherwise good sanitation. Between 31 October and 11 November 1999, 11 cases of typhoid fever occurred in Poppra District, Tak Province. Four cases were children < or = 14 years of age and the remaining 7 were adults 15-24 years old. Hemoculture was performed in 10 of the 11 cases, of whom 5 (50.0%) were positive for Salmonella Typhi. All the isolates were of Vi phage type E14 which was resistant to chloramphenicol, ampicillin, co-trimoxazole, tetracycline, and streptomycin but sensitive to kanamycin, ofloxacin, ciprofloxacin, and cefotaxime. One confirmed case developed intestinal perforation leading to death. A case-control study revealed a significant association between disease and drinking unboiled spring water. The implication of spring water was supported by the presence of faecal contamination in the spring water source. Rapid identification of the possible transmission source and prompt implementation of control measures curtailed the spread of this outbreak.