Hepatitis B is one of the most common and most serious infectious diseases caused by viruses. The WHO estimates that two billion people worldwide are infected with the hepatitis B virus (HBV). 240 million of them have already developed chronic hepatitis, more than 780’000 people die each year of the consequences. In Switzerland, around 30’000 people are living with the virus. Hepatitis B is highly contagious. The risk of contracting hepatitis B from a contaminated needle is 50 to 100 times higher than the risk of getting infected with HIV. Since the introduction of vaccines, new infections have dropped. Acute infections do not usually cause lasting damage. The infection is considered chronic if the viruses are detectable in the blood stream for more than six months.
The virus is transmitted via contaminated blood or other bodily fluids such as saliva, tears, semen or vaginal secretions. Unprotected sexual intercourse, exchanging needles when intravenously injecting drugs and passing the virus from mother to child at childbirth are further ways of transmission. Since 1980, each blood donation is tested for hepatitis B in Switzerland. New infections from blood transfusions are thus extremely rare.
Injecting drug users used to be most at risk of contracting hepatitis B. Today, people who have unprotected sexual contact – heterosexuals as well as homosexuals – are the biggest high-risk group. Also, migrants from countries with high hepatitis B infection rates are more likely to carry the virus themselves – often without knowing it. This applies to people from Asia, Africa (south of the Sahara), South America, the Middle East, the Mediterranean and Eastern Europe. Hepatitis B is one of the most common occupational diseases among healthcare professionals. Particularly vulnerable to infection are children of infected mothers.
The incubation period for hepatitis B is 60 to 120 days. The course of the infection varies considerably. Most people with a hepatitis B infection, acute or chronic, experience only nonspecific symptoms or none at all. Some show a yellowing of skin and eyes, have dark urine, suffer from extreme fatigue, nausea, vomiting or abdominal pain. A hepatitis B infection can progress into a chronic liver infection, which can lead to liver cirrhoses or liver cancer. While over 90 per cent of healthy adults with a hepatitis B infection recover completely within a year, up to 90 per cent of infected newborns and children will develop a chronic infection.
Raised levels of certain liver enzymes could indicate a hepatitis B infection. Several laboratory tests can prove the existence of antibodies and virus proteins. These tests show whether the infection is recent or chronic and also provide proof of immunity.
A highly effective vaccine, injected three times, provides protection against hepatitis B. In Switzerland, it has been recommended since 1997 to vaccinate all children aged 11 through 15 as well as all high-risk groups such as children of infected mothers. They are vaccinated against hepatitis B immediately after birth. People living in the same household or having a sexual relationship with someone who is infected should get vaccinated against hepatitis B and so should healthcare workers. The health insurance covers the cost of the vaccination.
Using condoms during intercourse reduces the risk of infection with the hepatitis B virus. Risk of infection in everyday life is minimal. However, electric razors or toothbrushes should not be shared. Tattooing and piercings can also pose a risk of infection if not carried out under sterile conditions.
As acute hepatitis B in adults usually clears by itself without causing lasting damage, no treatment is required. Chronic hepatitis B is treated with antiviral medicines containing pegylated interferon alpha or other medicines with antiviral agents. There is about a 40 per cent chance of being cured. However, genetic make-up of the virus usually remains in the liver, which makes a full recovery from chronic hepatitis B unlikely. Treatment reduces the viral load in the blood – and therefore the risk of inflammation of the liver and the development of liver cirrhosis and liver cancer. Patients with advanced liver disease may be given a liver transplant.