We have a serious challenge in South Africa with hepatitis B virus infection. Approximately six to eight per cent of South Africans are silently chronically infected, writes PROFESSOR MARK SONDERUP.
HEPATITIS is a term meaning ‘inflammation in the liver’. There are many causes of inflammation in the liver, amongst these include medications, toxins such as alcohol, auto-immune conditions where your own immune system sets up inflammation in your liver, fatty change in your liver from being overweight, and often diabetic, and a large group of viral infections that can cause inflammation. We call these the hepatitis viruses, and for convenience the letters of the alphabet have been used to provide names to them.
In the early 1960s, a virus that causes an acute infectious hepatitis commonly affecting young people and who get a classic syndrome of ‘yellow jaundice’ was identified and called hepatitis A. People who get hepatitis A may become yellow (jaundiced) and tend to recover with long-term immunity. There is no chronic form of hepatitis A.
A few years later, another virus that similarly can cause an acute hepatitis but was more difficult to clear and could develop into what we call chronic infection was identified. This virus was called hepatitis B virus. Later, a number of people were noted to develop hepatitis after having blood transfusions and, on testing, they were neither hepatitis A nor B virus positive. This virus was eventually identified (only in 1989) and was named hepatitis C virus.
Hepatitis C virus is another such virus where many people who become infected are at risk of not clearing the virus and develop chronic infection. Finally, two other viruses were identified, hepatitis D and E. Hepatitis D virus is a strange virus that requires people to have hepatitis B to make people susceptible to infection and the hepatitis E virus can cause an acute infectious hepatitis very much like hepatitis A. This is where the alphabet ends, for now.
In South Africa, we see all the viruses except hepatitis D virus, that is very uncommon. Hepatitis A is highly prevalent and is acquired from ingesting food that has been handled by somebody, who inadvertently is infected and does not actually know they are infected and are excreting virus. Through handling food, typically uncooked raw food, someone ingests it and becomes infected. Hepatitis A virus has a very effective vaccine that can fully protect you.
We have a serious challenge in South Africa with hepatitis B virus infection. Approximately six to eight per cent of South Africans are silently chronically infected. In South Africa, it is mostly acquired during childhood. This is a common pattern of transmission in South Africa and in sub-Saharan Africa, where children before the age of five are exposed to the virus from other children, who are inadvertently and unknowingly already hepatitis B chronically infected.
Another means of infection is from mother transmitting it to her baby peri-natally during the birthing process or in the immediate post-natal period. Again, the mother is inadvertently and unknowingly infected and transmits the virus.
Hepatitis B virus is also potentially a sexually transmitted or needle transmitted infection in adults. However, an important issue is the time of your life at which you are exposed to the virus, in fact, determines your risk of not clearing the virus and developing chronic infection. This is largely due to the maturity of your immune system at the time that you are infected.
If a baby is infected immediately post-delivery, they have an up to 90 per cent chance of developing chronic infection. If a child within the first few years of life is exposed to another child and acquires hepatitis B, their risk is anywhere between 30 per cent and 50 per cent of not clearing infection and developing chronic infection whereas an adult acquiring infection has a very low chance (less than five per cent) of not clearing the infection. From this one can see that the more mature your immune system is the more likely you will clear this virus.
Why do we even worry about hepatitis B?
People who are chronically infected do not have any symptoms. They are not sick and do not know that they are chronically infected. There is, however, a significantly elevated risk of them developing chronic liver damage throughout their decades of life and, more concerningly, they have a significantly increased risk of developing liver cancer.
Globally, hepatitis B virus infection is the most common risk factor for people with primary liver cancer. Because people are asymptomatically infected the first time they present with symptoms may be with already advanced chronic liver disease or cirrhosis or liver cancer. Both these situations are quite devastating and thus prevention is key. An effective vaccine has been available since 1980 and has been included in the South African vaccine programme since 1995.
Vaccination is highly effective in preventing chronic infection and the current vaccine schedule involves children receiving three doses of vaccine at six, 10 and 14 weeks. To prevent so-called mother to child transmission, a birth dose vaccine is now recommended and has been introduced in many countries worldwide. South Africa has as yet not done this but there is significant moves towards introducing birth dose hepatitis B virus vaccination for the reasons that are explained in this article.
What do we need to do with hepatitis B?
- Everybody and every child to be adequately vaccinated including a birth dose plus the remaining doses. Vaccination is fully protective and protective for life.
- Screening of unvaccinated people – those born before 1995 and who were not vaccinated and are at risk of having chronic infection. Routine HIV testing is already commonplace. This should be once off for hepatitis B. If people test negative for hepatitis B and have never been vaccinated, this is strongly advised.
- Prevent mother to child transmission – screen pregnant women and offer them interventions to avoid infecting their babies.
- Adults, who are chronically infected must be linked to care.
With hepatitis C people, those at risk included people who received blood transfusions prior to 1992 and inadvertently became infected with hepatitis C and presently people who are users of injecting drugs. People who inject drugs and share needles are at high risk of chronic hepatitis C virus infection.
In South Africa between 30 per cent and 75 per cent of people who inject drugs are hepatitis C infected. These and others need to be identified through screening because, again, they are asymptomatically infected and only become symptomatic with features of liver disease or even liver cancer and thus already too late to intervene.
People with hepatitis C virus infection should be referred for treatment that currently is easy, simple, well tolerated, involves taking one tablet, once a day for 12 weeks and this offers you a more than 95 per cent chance of curing you of the virus. This is highly effective therapy and people should be identified and speedily linked to care.
In summary, we have made massive strides in preventing and treating viral hepatitis. All need to act and demand vaccination, testing and treatment to produce a viral hepatitis-free generation and eliminate viral hepatitis.
- Professor Mark Sonderup is based in the Division of Hepatology, Department of Medicine, University of Cape Town, and at Groote Schuur Hospital.