Fight hepatitis B to prevent liver cirrhosis and cancer

Hepatitis B, a viral infection affecting the liver, is the leading cause of liver cancer in Africa, accounting for up to 80 per cent of liver cancer cases. This is despite the infection being preventable through vaccination.

Hepatitis B is highly infectious and is spread from mother to child during birth, during transfusion with infected blood and blood products, during dialysis, sexual intercourse with multiple partners, sharing syringes among injectable drug users and during prolonged close contact with infected people.

Only a third of infected adults have symptoms such as yellow eyes and abdominal pain. In many cases, there are no symptoms (especially in children) or the symptoms are mild and are mistaken for flu or malaria. When there are no symptoms, the diagnosis is made incidentally, for example when screening blood donations or during medical check-ups.

A blood test is used for diagnosis, and other tests like liver ultrasound, and the less common liver biopsy may be carried out to assess the degree of liver involvement.

The initial infection after exposure is acute, with either complete recovery, or progression to chronic disease. When symptoms develop in acute hepatitis B, management includes rest, adequate hydration and proper nutrition. Avoidance of other factors like alcohol, which may make the liver inflammation worse, is also advised.

NO CURE

There is no specific treatment or cure for acute hepatitis B, and most adults do not progress to chronic disease.

However, many children who were infected from birth or who are below the age of five do. Chronic hepatitis B is diagnosed by the persistence of certain blood markers for six or more months after initial infection. Chronic infection is characterised by abdominal pain, yellow eyes, dark urine or abnormal liver tests, but in some cases there are no symptoms.

The key concern in chronic hepatitis B is the risk of development of liver cirrhosis and/or liver cancer. For those who develop chronic infection, there are once-a-day tablets which prevent the virus from multiplying and these are taken for several years, or indefinitely.

The risk of developing liver cirrhosis and liver cancer decreases when virus multiplication is halted. Once weekly injections for a period of one year are also available, but they are expensive and have significant side effects.

Hepatitis B is preventable by vaccination and is included as part of the Kenya Expanded Programme on Immunisation (KEPI), through which newborns are vaccinated at six, 10 and 14 weeks.

In some facilities, a dose is given at birth. Adult vaccinations are given as a series of three injections over six months.

Booster doses may be necessary if a blood test reveals that immunity against hepatitis B is not at the desired level. The vaccine is 80 to 100 per cent effective in preventing infection, or clinical hepatitis, in those who receive the complete dose.

To identify those who would benefit from vaccination and those who require medication to halt the progression to liver cirrhosis and cancer, increased coverage of screening is necessary.

Dr Rajula is a consultant gastroenterologist, while Dr Riunga is a consultant in infectious diseases. They both work at the Aga Khan University Hospital, Nairobi