A Review of Hepatitis B Virus Infection in Sri Lanka

Abstract

Hepatitis B virus (HBV) infection is a major public health concern in many Southeast Asian, South Asian and African countries. HBV infection is transmitted sexually or by other parenteral routes. HBV causes an acute viral hepatitis or chronic infection, largely based on the age at which the infection is acquired. In the majority of infected infants, HBV causes a chronic protracted infection for decades without symptoms. After several decades, the infection might flare up to give rise to an active hepatitis followed by sero-conversion to anti-HBs. However, the vast majority of patients with chronic HBV (CHB) infection will have chronic liver disease. Some with CHB infection develop a primary liver cancer, hepatocellular carcinoma (HCC) later in life. Approximately 25 percent of chronically infected individuals die prematurely of cirrhosis or HCC. The prevalence of HBV infection in Sri Lanka is estimated to be less than 2%. Sri Lanka is therefore considered a country of low endemicity. This prevalence rate of HBV in Sri Lanka is very different to that in many other South Asian countries such as India and Bangladesh. Diagnosis of HBV infection in Sri Lanka is carried out in many private and state laboratories using immunochromatography based rapid assays or ELISAs for HBV surface antigen (HBsAg) detection. Those with latter stages of CHB are treated with currently available nucleotide / nucleoside analogues in some private sector hospitals where testing facilities for virus load during different stages of treatment is available. Sri Lanka has a policy of immunizing healthcare workers (HCW) who are at risk of acquiring HBV occupationally. Sri Lanka included HBV immunization in the Expanded Program of Immunization (EPI) with effect from 2003. In all HBsAg immunization programmes for HCW, testing for the protective anti-HBs response is mandatory in those who receive a complete course of immunization in order to ensure immunity in responders and to re-vaccinate non-responders.