The Five Hepatitis Viruses – A, B, C, D and E

Viral hepatitis is an inflammation of the liver caused by a virus. So far, five different types of hepatitis viruses have been identified. They are called hepatitis A, B, C, D and E. All five types cause short-term (acute) infections from which most patients recover quickly. An acute infection can occur with only mild symptoms – or even none. Sometimes jaundice (yellowing of eyes and skin), dark urine, extreme fatigue, nausea, vomiting and abdominal pain are signs of an acute infection.

Inflammations caused by hepatitis B, C and D viruses can lead to chronic hepatitis and thus entail life threatening complications such as cirrhosis of the liver (scarring), liver failure and liver cancer. Around the globe, approximately 400 million people suffer from chronic hepatitis B and C. They represent the majority of cases of liver cirrhosis and cancer. Each year, 1.5 million people die from hepatitis infections.

In developed countries, hepatitis C causes more deaths than HIV/Aids. In Switzerland, an estimated 1.5 per cent of the population is chronically infected with hepatitis C and/or B. 40’000 people are thought to live with a chronic hepatitis C infection and another 40'000 with chronic hepatitis B.

Transmission

Hepatitis A and E are transmitted via the intake of food or water that has been contaminated with faeces, or via direct contact with infected individuals. Hepatitis B, C and D are transmitted via infected blood or other bodily fluids. Common ways of transmission are the exchange of contaminated needles among intravenous drug users and blood transfusions. During childbirth, hepatitis B can easily be passed from mother to child. However, vaccinating the newborn can prevent an infection. Hepatitis B is also transmitted via unprotected sexual intercourse.

Progression

As with all viruses, hepatitis viruses can only survive and multiply within cells, in the case of hepatitis they are predominantly hepatic cells. Viruses do not usually damage the affected cell itself. But to eliminate the invading virus, the whole hepatic cell needs to be destroyed. If the immune system starts this process quickly and efficiently, all infected cells – and thus all viruses – are destroyed, and the infection is cured. If the immune system fails to react fast, as can happen with hepatitis viruses B and C, the infection of the liver can continue many years, become chronic and lead to scarring. As a consequence, liver cirrhosis can occur.

Prevention

Hepatitis infections can be prevented by safe food and clean water (hepatitis A/E), vaccinations (hepatitis A/B/E), testing blood donations and dispensing sterile injecting equipment as well as monitoring existing infections (hepatitis B and C). However, today’s prevention measures and awareness efforts are not nearly enough. There are too many who do not know that they carry the virus, because they experience only mild symptoms or none at all. It is therefore paramount to identify and examine the infected. Only then can they benefit from the new treatment regimes. You can prevent a hepatitis infection if you:

  • practice safe use with drugs: use sterile injection equipment and utensils as well as sterile straws if snorting
  • practice safe sex, especially when frequently changing partners (this applies to HIV as well)
  • make sure any tattooing and piercing is done under sterile conditions
Vaccination

There are vaccines available that protect against hepatitis A and B. Who should get vaccinated?

Against hepatitis B

In Switzerland, a general vaccination for all children aged 11 through 15 years is recommended. The vaccination can also be performed on babies. Newborns of infected mothers should be vaccinated to prevent a possible transmission during childbirth. The vaccination is also recommended for adults who have not yet been vaccinated and who are at an increased risk of infection: healthcare workers, injecting drug users, people with poor immune systems or people who frequently change sexual partners. There is a combination vaccine available against hepatitis B and A, recommended for anyone travelling to regions where hepatitis A is common.

Against hepatitis A

People who are frequently travelling to high-risk areas, such as Asia, including Turkey, the African continent, Central and South America and Eastern Europe, should be vaccinated. For livelong protection, two injections of the vaccines are needed. Talk to your GP at least four to six weeks prior to your journey or visit a travel clinic. More about hepatitis A

More information: www.safetravel.ch

How effective are vaccinations?

Vaccines against hepatitis A and B are among the most effective and safest. As with all vaccinations, side effects such as skin reactions at the injection spot can occur. Three injections are needed to vaccinate against hepatitis B, two against hepatitis A and three for the combination of A and B.

Treatment

Most infected people recover quickly from an acute hepatitis without needing medical treatment. Chronic hepatitis B and C infections can be treated, but the chances of a full recovery are slim, especially when chronically infected with hepatitis B. Highly effective new hepatitis C medicines have recently been released. But most patients, in poor countries in particular, lack access to treatment because of inadequate evaluation of patients, a shortage of medical services and the high costs of some of the new medicines. The latter has also led to treatment access restrictions for certain groups of hepatitis C patients in Switzerland. Vaccination is the best protection against hepatitis A and B. Treatment of hepatitis C is currently changing fundamentally: Moving away from interferon therapy towards treatment with antiviral medicines that affect the virus directly, leading to shorter, more efficient treatments with fewer side effects.

Other Hepatitis Pathogens

Only 80 to 90 per cent of acute and chronic hepatitis cases can at present be linked to known viruses. That is why worldwide research focuses on the discovery of new types of hepatitis viruses. Every one to two years, the discovery of a new type is announced; more often than not, they turn out to be false. Recognised, but of little medical relevance, are:

  • GBV-C: This virus has been discovered in a surgeon, and even though it appears mainly in hepatic cells, it causes rarely or never any illness.
  • TT-Virus, SANBAN-Virus, TTV-like Minivirus, SEN-Virus, Sentinel-Virus: All of these belong to the same family of viruses. They infect hepatic cells, but rarely or never cause any illnesses either.