Hepatitis B, a viral infection affecting the liver, has been cited as the leading cause of liver cancer in Africa, with some estimates attributing up to 80 per cent of liver cancers to Hepatitis B infection. This presents an opportunity for intervention as Hepatitis B is preventable through vaccination.
Hepatitis B virus is highly infectious and can be spread in a variety of ways. Examples include from mother to child around the time of delivery, transfusion of infected blood and blood products, dialysis, sexual intercourse particularly with multiple partners, use of injectable drugs, and prolonged close contact with those who are infected.
In the majority of cases, infection produces no symptoms and diagnosis is made incidentally for example during screening for blood donations, or medical check-ups. Diagnosis of Hepatitis B infection is done through a blood test. Additional tests to assess the degree of liver involvement may be carried out and may include an ultrasound of the liver, and much less common, a liver biopsy.
There are two phases of hepatitis B, acute and chronic. If one is exposed to Hepatitis B virus, then the initial infection is termed acute. Overall, only about a third of infected adults will have symptoms such as yellowness of the eyes and abdominal pain. Most others will either have no symptoms, or only mild symptoms which can easily be mistaken for flu or malaria. It is rare for children to display symptoms.
After an acute Hepatitis B infection, there may be complete recovery, or progression into chronic disease. Chronic Hepatitis B is diagnosed by the persistence of certain blood markers of hepatitis about six months, or more after the initial infection.
Most adults will not progress to chronic disease, but a large proportion of children who are infected from birth, or below the age of five years will develop the chronic form. This may exist without symptoms or with occasional bouts of hepatitis characterised by abdominal pain, yellow eyes, dark urine or abnormal liver tests. The key concern in chronic Hepatitis B is the risk of development of liver cirrhosis and, or liver cancer.
When symptoms develop in acute hepatitis B, management is supportive with rest, adequate hydration and proper nutrition. Avoidance of other factors that may make the liver inflammation worse such as alcohol is also advised. There is no specific treatment or cure for acute Hepatitis B.
Dr Rajula is a consultant gastroenterologist while Dr Riunga is a consultant in Infectious Diseases at Aga Khan University Hospital, Nairobi.