Hepatitis B

Like hepatitis A, hepatitis B is also caused by viruses that can cause inflammation in the liver. There are two possible scenarios after infection. One is that in the course of six months hepatitis B is cured, which is the case in 90% of adults. The other scenario is when the HBV becomes chronic. In the first scenario the affected person becomes immune to hepatitis B viruses and usually remains so for the rest of his or her life. People with a fundamentally weakened immune system are more likely to develop chronic hepatitis B (infants, children, the elderly, the chronically ill with weakened immune systems, HIV patients or organ transplant recipients).

In babies, the probability of developing chronic HBV is as high as 90%. Chronic HBV can follow several different courses. It is impossible to predict if and when in life HBV will lead to cirrhosis or liver cancer. HBV sometimes takes a mild course. However, an initially mild course can also lead to cirrhosis and/or liver cancer after years or decades.

It is important to know that even ostensibly healed HBV can be reactivated after many years if the immune system is severely impaired by another illness, such as AIDS or certain drug treatments (e.g. chemotherapy or immunosuppressants, such as those used after a transplant). To prevent the onset of HBV and progression to cirrhosis and all its complications, virus-inhibiting drugs can be administered preventively and it is recommended that the condition is closely monitored.

Symptoms

Dangerously, symptoms rarely occur with acute HBV. At the start of a HBV infection, so in the acute phase, mild flu-like symptoms such as fever may occur, as well as nausea, pale stools, dark urine or yellow-coloured skin and whites of the eyes. One of the most common symptoms of chronic HBV is fatigue. Beyond this hepatitis B is often symptomless until cirrhosis or liver cancer develops.

Diagnosis

To diagnose HBV, doctors will look for the HB antigen (HBsAg) and two antibodies, HBcAg and HBsAg. The HBs antigen is the coating of the HBV virus and can be detected via a blood test if an infection exists. Both anti-HBc and anti-HBs antibodies are part of the immune reaction to the virus. These specific antigen and antibody values denote the presence of a hepatitis B infection - and can show whether it has already healed or if vaccination was effective.

The following list is intended as a guide to how blood values are interpreted:

Acute and chronic hepatitis B: HBsAg positive, anti-HBc positive, anti-HBs negative.

Cured hepatitis B: HBsAg negative, anti-HBc positive, anti-HBs positive (except in the event of a long-standing infection)

Healthy and vaccinated: anti-HBs as the only positive marker. No HBsAg, no anti-HBc.

Healthy and not vaccinated: all markers negative (Note: in the first weeks after an infection, the blood count may also remain unremarkable.)

A blood test for HBV DNA (genetic material of the virus) is complex and often not necessary during the initial diagnosis. However, where doubt exists, this can provide additional evidence.

Causes

Transmission of hepatitis B is usually via bodily fluids, such as blood, semen, vaginal fluids and saliva. Therefore, transmission usually occurs during sexual intercourse. In this context, transmission seems to depend significantly on the amount of virus present. Mothers can also transmit the disease to their newborn babies, and poor hygiene in medical situations, tattos, piercings and infected needles can also lead to infection.

The most at risk are cohabitants and sexual partners of those affected and people who frequently change partners. Healthcare workers are at risk because they come into contact with blood or blood products. Taking drugs is also a risk due to shared needles. The risk is also increased for people in countries with a high level of hepatitis B.

Prevention and treatment

Vaccination against hepatitis B is safe and efficient. It is an inactivated vaccine that does not contain any active virus.

Preventative measures to avoid catching HBV include: safer sex, wearing protective gloves when handling the blood others and using disinfectants to sterilise the environment (for example, in healthcare settings and tattoo studios). If relatives have (or could have) contracted HBV, it is advisable not to share personal hygiene items such as toothbrushes or razor blades. In Switzerland pregnant women are tested for HBV. If the mother is found to have hepatitis B, active and passive vaccination can prevent transmission to the newborn.

If a hepatitis B infection is present, the first stage (acute phase) is normally not treated because it can resolve on its own. Taking medication during this early phase does not promote spontaneous recovery. Antiviral medications are used in the acute phase for mitigation.

If the hepatitis B infection becomes chronic, there are two different types of treatment. One type of medication targets the reproduction of the virus by inhibiting it. These drugs include nucleoside or nucleotide analogues. PEG interferon works differently. It stimulates the immune system. The goal of both treatments is to stop or inhibit the disease, rather than to cure it. If the HBV is mild, monitoring will suffice. The appropriate treatment should be discussed with a doctor.