Hepatitis B

Hepatitis B is a serious liver infection caused by the hepatitis B virus (HBV), transmitted through blood, body fluids, and from mother to child at birth. Nigeria has a very high endemic burden — an estimated 20 million Nigerians live with chronic hepatitis B, one of the highest rates in the world. Many people are infected at birth or in childhood and remain unaware for decades while the virus silently damages their liver. Chronic hepatitis B is the leading cause of liver cirrhosis and liver cancer in Nigeria. There is no cure, but an effective vaccine prevents infection, and antiviral treatment can suppress the virus and prevent complications.

Many people — especially those infected at birth — have no symptoms for years or decades. Acute hepatitis B (1–4 months after infection, if symptoms occur): • Fatigue and general weakness • Nausea, vomiting, and loss of appetite • Abdominal pain over the right side (over the liver) • Jaundice: yellowing of the skin and whites of the eyes • Dark (cola or tea-coloured) urine • Pale or clay-coloured stools • Fever • Joint pains Most adults with acute hepatitis B recover fully. In 5–10% of adults (and up to 90% of infants infected at birth), infection becomes chronic. Signs of advanced chronic liver disease (cirrhosis): • Progressive fatigue • Abdominal swelling (ascites) • Easy bruising and bleeding • Confusion (hepatic encephalopathy) • Vomiting blood (from oesophageal varices) • Weight loss and muscle wasting

Hepatitis B is caused by the hepatitis B virus (HBV), a DNA virus that infects liver cells. Transmission occurs through: • Mother to child at birth: the most common route of chronic infection; risk up to 90% without preventive vaccination • Unprotected sexual contact with an infected partner • Blood-to-blood contact: – Sharing needles or syringes – Unsterilised tattooing or piercing instruments – Unsafe medical or dental procedures – Blood transfusions (risk greatly reduced by modern screening) – Needlestick injuries in healthcare workers HBV is NOT spread through: casual contact, hugging, sharing food or water, coughing, sneezing, or breastfeeding (unless nipples are cracked).

• Being born to an HBV-infected mother without receiving the birth-dose vaccine • Having an HBV-infected household member • Unprotected sex with infected partners or multiple partners • History of sexually transmitted infections • Injecting drug use • Unsafe medical, dental, or surgical procedures • Tattooing or piercing with unsterile instruments • Healthcare workers • Unvaccinated individuals in endemic areas (all of Nigeria)

• Chronic hepatitis B infection in 5–10% of adults and up to 90% of infected newborns • Liver cirrhosis: progressive scarring causing liver failure • Liver cancer (hepatocellular carcinoma, HCC): Nigeria has one of the highest rates of HCC in the world, predominantly driven by hepatitis B; prognosis is very poor when detected late • Liver failure: ascites, variceal bleeding, encephalopathy, death • Co-infection with hepatitis D virus (worsens liver disease) • Kidney disease (HBV-associated nephropathy)

Vaccination — the most effective protection: • Hepatitis B vaccine is part of Nigeria's routine childhood immunisation schedule (birth, 6 weeks, 14 weeks) • The birth dose: given within 24 hours of delivery — is critical to prevent mother-to-child transmission • Unvaccinated adults can still receive and benefit from the vaccine series Preventing transmission: • Use condoms consistently • Never share needles or injection equipment • Insist on sterile instruments for medical, dental, and tattooing procedures • Healthcare workers should follow universal precautions Mother-to-child prevention: • All pregnant women should be tested for hepatitis B • Newborns of infected mothers must receive the hepatitis B birth-dose vaccine AND hepatitis B immunoglobulin (HBIG) within 12 hours of birth For those with chronic hepatitis B: • Regular monitoring (liver function tests, viral load, ultrasound) • Antiviral therapy (tenofovir or entecavir) where indicated • Avoid alcohol: it accelerates liver damage • Liver cancer surveillance ultrasound every 6 months