An investigation of Hepatitis A outbreak from contaminated drinking water in a prison, Bangkok, Thailand, January-April 2017

Abstract

Background: On March 7, 2017, Institute for Disease Control and Prevention (IDUC) had reported three suspected HAV patients were admitted to the Medical Correctional Hospital and about 40 suspected cases in the Correctional Institution for Male Drug Addicts unit 4. The disease control unit of IDUC, The Epidemiology Division and Health Office and Chatuchak office, the Bangkok Metropolitan Administration (BMA) conducted an investigation from March 8–April 22, 2017.
Methods: Descriptive epidemiological study, consisting of 1) reviewing medical records of the case and hepatitis situation of the patients who received hospital treatment from 1 January to 8 March 2017. 2) Conducting active case finding among prisoners, food handlers, and staff. 3) collecting sera and stool samples from patients and food handlers for Hepatitis A IgM using enzyme- linked immunosorbent assay, and Polymerase Chain Reaction respectively, and 4) conducting environmental investigation in prison kitchen and drinking water and used water system.
Results: Totally 141 patients were identified (between 16 February–19 March 2017) including 61 confirmed cases and 80 suspected case. Cases were identified only at unit 4 (specific unit attack rate 18.03%). The median age was 23 years (Minimum was 19 Maximum was 42). Unit 4 had 11 rooms with 782 prisoners lived in the unit. The majority of cases lived room no. 11 (Halls), room no. 10 and room no. 7 amount 46, 18 and 14 cases respectively. First case occurred in 2 weeks after the pipe tab water broke down near septic tank. Sequencing are found in all the same breeds, whereas ice and water not found hepatitis A virus.
Conclusions and discussions: A common point source Hepatitis A outbreak was identified among prisoners, and drinking water contaminated with stool containing hepatitis A virus was the most likely source of the outbreak. After replacing the water supply pipe on 17 February 2017, the prisoner changed the behavior and closed the prison for a period of 60 days from the last patient. No more patients were found.