Prevention of mother to child transmission of hepatitis B virus infection in Nigeria: A call to action

Abstract

Background: Sub- Sahara Africa including Nigeria has the second largest global burden of chronic carriers of hepatitis B virus (HBV) infection after Asia. Mother-to-child transmission (MTCT) of HBV is the most commonroute of transmission in high endemic areas .MTCT of hepatitis B virus infection continues to occur despite the interventions of hepatitis B vaccinations and immunoglobulins in settings where it is practiced. Infants most at risk are those whose mothers have high HBV DNA viral loads and produce the protein HBeAg. Various Nigerian studies have reported high HBV infection rates as well as HBeAg positivity among pregnant women. These HBV infections usually occur intrapartum and rarely inutero. Mothers with HBeAg positivity known to be associated with higher HBV DNA viral loads have been linked with higher chances of MTCT as HBeAg is the only structural HBV protein that can cross into the placental circulation. In the absence of post exposure prophylaxis about 40 percent of infants delivered by HBV infected mothers could develop HBV infections, and about 25% of them may come down with chronic hepatitis and resulting possible complications including liver cirrhosis and hepatocellular cancer later in life. The prevention of transmission of retroviral infection from motherto- child has been a success story of the 21st century and such feat could be replicated for HBV infection. The standard PMTCT of HBV currently will comprise: timely prenatal screening, starting anti-viral therapy for pregnant women with HBeAg positivity and high viral load, infant postexposure prophylaxis and followup of infants of HBsAg positive mothers. There is no co-ordinated PMTCT of HBV programme in place in our setting despite the huge burden of the disease in Nigeria. Hence the need therefore to develop a home grown PMTCT programme of HBV to help tackle the burden of the disease in our country. An evidence based review of current best practice guidelines for the prevention of mother-to-child transmission of HBV for use in low and medium resource income settings with hepatitis B hyperendemicity will be quiet apt in this circumstance. This document therefore will be useful as a quick guide to Paediatricians, Obstetricians, Family Physicians, General Practice Doctors and other allied health workers charged with the care of pregnant mothers and their young children.
Methods: Relevant literatures published in English language or translated into English were searched manually and electronically in PUBMED and SCOPUS for the period between 1990 and 2016 on the subject. Keywords searched included: epidemiology of HBV infection, MTCT of HBV, and its preventive strategies including prenatal screening, antiviral agents in pregnancy, infant post exposure prophylaxis and follow-up of infected children.
Results: Over 35 scholarly articles on HBV epidemiology, MTCT, and preventive measures as well as follow –up models were retrieved and analyzed.
Conclusion: Universal screening of all pregnant women for HBV infection is the most effective strategy for the prevention of MTCT of HBV, as effective preventive measures could be applied starting from pregnancy to delivery while infants of HBsAg positive mothers should receive timely post exposure prophylaxis and followed up for possible development of chronic hepatitis B infection.

Key words: Prevention of mother to child transmission; Hepatitis B virus infection; Resource limited settings.