Epidemiology and factors associated with amoebic liver abscess in northern Sri Lanka.

BACKGROUND: Clinically diagnosed amoebic liver abscess (ALA) caused by Entamoeba histolytica has been an important public health problem in Jaffna district, northern Sri Lanka for last three decades. In order to draw up a control strategy for elimination of this condition, knowledge of its epidemiology and factors associated with this condition in the local context is vital.

METHODS: All clinically diagnosed ALA patients admitted to the Teaching Hospital, Jaffna during the study period were included in the study and the data were collected using an interviewer administered questionnaire. One hundred blood samples from randomly selected toddy (a local alcoholic drink consisting of the fermented sap of the Palmyrah palm) consumers and 200 toddy samples were collected. Toddy samples were cultured in Robinson's medium to establish the presence of Entamoeba histolytica in the sample. Climatic data and the total toddy sales in the district were obtained from the Meteorological and Excise Departments respectively. A sub group of randomly selected 100 patients were compared with 100 toddy consumers who were negative for E. histolytica antibody to explore the potential risk factors.

RESULTS: Between July 2012 and July 2015, 346 of 367 ALA patients were enrolled in this study. Almost all patients (98.6%) were males with a history of heavy consumption of alcohol (100%). Almost all (94.2%) were within the age group 31-50 years. None of the cultured toddy samples grew E. histolytica. The monthly incidence of disease peaked in the dry season, matching the total toddy sales in the district. Age, type of alcohol and frequency of drinking were identified as potential risk factors whereas frequency of alcohol consumption and type of alcohol (consuming toddy and arrack) were identified as the independent risk factors. Moreover, the knowledge, attitude and practices towards ALA were poor among participants and the control group.

CONCLUSIONS: Though the number of cases has declined in recent years, ALA still remains as an important public health problem in Jaffna district. The transmission route of E. histolytica leading to ALA has to be further explored. Moreover, greater awareness among the public who are at risk would be beneficial in order to eliminate the disease.