Abstract
Epidemiologic investigation into an Outbreak of Typhoid Fever Recognized by EIectronic Data Interchange inGyeongsangbuk-do, 2003Purpose Fourteen cases of typhoid fever occurred in Gyeongsan-si, Gyeongsangbuk-do from May 22 to July 19, 2003.Especially, 6 cases were students of Y University located in Gyeongsan-si This investigation was carried out to study theinfection source and transmission of typhoid fever and to institute an effective prevention counterplanMethods The authors conducted an epidemiologic survey from June 25, 2003 among the 14 cases, restaurants andemployees of the whole neighborhood of Y University Widal test was carried out for the restaurant employees andschoolmates of the 13-year-old case Miss Kim The authors executed a pulsed field gel electrophoresis (PFGE) forSalmonella typhi cultured from 9 cases The authors collected data about chloride and turbid levels of treated water fromApril to June in Gyeongsan-si water treatment. plant and repair work records of waterworks pipe line in Gyeongsan-si city hall Results All cases had used restaurants of the whole neighborhood of Y Umversity within 2 months before the typhoidfever symptoms were developed, but the restaurant that was rarely visited by any of the patients had a case to be matched Inthe results of the Widal test, 9 out of 45 of subjects (20 0%) were suspicious cases or showed a value to suggest pastinfection, in the results of PFGE test, there were 3 subtypes, and each subtype had a similar DNA fragments array In allcases the patients drank tap water when they visited the restaurants The restauiants provided dnriking water from filtered tapwater rather than boiled water, and all patients had drunk this water The chlorine level of the treated water was the normalvalue in the Gyeongsan-si water treatment plant, but in 21 times the value was the minimum standard level There was waterpipe construction woik in some tegions of the whole neighborhood of Y University The number of gastromtestmal patientsin 2003 was approximately 21 times that in 2002 at the health center in Y Umversity.Conclusions The possibility that typhoid fever was generated in the whole neighborhood of Y University is very highAmong various possibilities, the highest possibility is the pollution of tap water intake by water leakage of a water pipeThere was no case of patient infection after strengthening of the tap water disinfection Thorough disinfection, boileddrinking water and a periodic carrier inspection are necessary to prevent additional local occurrencea of these typhoid infections