Risk factors for viral hepatitis A infection in Gampaha District, Sri Lanka: an unmatched case control study

BACKGROUND: Hepatitis A virus (HAV) is one of the commonest food and water borne infectious diseases. The objective of the study was to determine the risk factors of HAV infection in the Gampha District in Sri Lanka. METHODS: This was an unmatched case control study conducted between January 2015 and November 2016 comprising of 504 participants with a case control ratio of 1:1. The study population included individuals of age 1 year and above who were permanent residents of the district. Cases included participants admitted to four secondary care state hospitals with an acute HAV diagnosed by detecting serum anti-HAV IgM antibodies. Controls were randomly selected individuals from the community with serum negative for Anti-HAV IgM and IgG. An interviewer administered questionnaire was used for the data collection and multiple logistic regression was applied to determine the independent risk factors. The results are expressed as adjusted odds ratios (AOR) and 95% confidence intervals (CI). RESULTS: Risk factors for HAV infection were poor knowledge regarding hepatitis (AOR;3.98, 95% CI = 1.97-8.05), unhygienic sanitary practices (OR = 2.73; 95% CI = 1.42-5.23), unhygienic practices related to drinking water (OR = 2.67; 95% CI = 1.37-5.21), residing in urban areas (OR = 5.94; 95% CI = 2.98-11.86) and lower family income (OR = 2.83; 95% CI = 1.30-6.13). CONCLUSIONS: The independent modifiable risk factors for HAV infection were poor knowledge regarding hepatitis, unhygienic sanitary practices, and unhygienic practices related to drinking water. Community awareness must be raised on hygienic practices and safe water drinking practices. Inequities of social determinates of health must be addressed.