Epidemiology of Hepatitis B Virus Infection in South-South, Nigeria: A Review

Hepatitis B virus (HBV) is a small enveloped DNA virus of the Hepadnaviridae family associated with infection of the liver, and a major public health problem globally. The virus preferentially infects the liver leading to hepatic complications such as hepatic carcinoma and liver cirrhosis. About two billion people globally have been estimated to be infected with hepatitis B virus and approximately 350-400 million others reportedly suffer from the chronic forms. An estimated two million of these carriers die each year as a result of complications. The mode of transmission of the disease is largely through unprotected sex, mother-to-child transmission (MTCT), contaminated blood and blood products and use of contaminated sharp objects or instruments. Africa is a high endemic area with 7–26% prevalence rate of HBsAg. Nigeria has been placed among the group of countries endemic for HBV infection with about 18 million infected. In recent years, the rates of prevalence of HBV have been increasing within the South-South part of the country. Serological and molecular techniques are currently employed not only in the diagnosis of this infection but also to assess the prognosis of the disease, guide therapy and monitor treatment responses. Treatment is highly supportive and two major groups of antiviral treatment licensed for the treatment of chronic HBV infection are pegylated interferon alpha and nucleoside or nucleotide analogues. Interrupting early transmission is key to breaking the cycle of ongoing HBV infection. In addition to active vaccination, the implementation of blood safety strategies including quality-assured screening of all donated blood and components used for transfusion may prevent transmission of HBV to a significant level.