hepatitis B

350 million people worldwide are infected with the hepatitis B virus, and 75% of these people live in Asia. Hepatitis B is an infection of the liver that is caused by the hepatitis B virus. The hepatitis B virus nestles in the liver cells after which the liver becomes damaged by the patient’s immune system.

An acute hepatitis B infection causes symptoms such as stomach aches, nausea, and jaundice. After the acute infection, the hepatitis B virus will be cleared from the body within a few weeks or months with 95% of the adult patients, but 5% will develop a chronic infection. Chronic HBV infection is defined as ‘seropositivity for hepatitis B surface antigens (HBsAG) lasting more than six months’. A chronic hepatitis B infection can cause liver cirrhosis and a small part of the patients may develop liver cancer.

TRANSMISSION

The hepatitis B virus is transmitted from one person to another by exposure to infected blood or bodily fluids that contain blood. Some possible forms of transmission are unprotected sexual contact (this means that hepatitis B is also considered to be a sexually transmitted or venereal disease, STD or VD), blood transfusions, re-use of contaminated needles, and there is the transmission from mother to child.

DIAGNOSIS

An infection with the hepatitis B virus can be established in several ways.

1. ncreased level of liver enzymes (ALAT and ASAT) released due to liver cell damaging: this is often a reason to examine further for hepatitis B (and C).
2. Positive antibodies against hepatitis B. When someone has become infected, the immune system will make antibodies: anti-HBs, anti-HBc, and anti-HBe. When the screening only shows a positive anti-HBs value, then this is the result of a prior vaccination.
3. Establishing the hepatitis antigen: HbsAg and HBeAG
4. PCR: this is an examination into a person’s DNA: this test can show the exact amount of hepatitis B in the blood and it can also be determined with what type (serotype) of hepatitis B the contamination took place.

VACCINATION

Hepatitis B infections can be prevented with vaccinations. It is, therefore, extremely important that everyone who runs the risk of getting exposed to the hepatitis B virus is vaccinated. This group include men who have sexual relations with other men (MSM), intravenous drug users, and people who travel to countries where they may need a blood transfusion or plan to have sex. A complete and adequate vaccination consists of 3 injections that must be administered over a period of six months. You will need to have your blood tested four to eight weeks after the final vaccination. The laboratory will then check whether the body has produced enough antibodies against the virus. The amount of antibodies is called ‘anti-HBs titre’. In the Netherlands, this titre must be higher than 10 international units per litre (10 IU/L). When this is the case, the person is sufficiently protected against the virus. This protection is probably for life.

Medical Centre Jan van Goyen offers free vaccinations against hepatitis B to HIV patients.

Examination of a new patient with hepatitis B infection

• Anamnesis: a consultation with the physician or specialist nurse about your medical history, current symptoms, general health, and use of alcohol and drugs.
• Physical examination
• Laboratory analysis: apart from the analysis of the liver function and the current hepatitis B infection, a further examination will be conducted into possible viral coinfections (other hepatitis viruses and HIV).
• Ultrasound upper abdomen
• (In some cases) fibroscan: this is a new technique whereby the amount of scar tissue in the liver is determined.

THERAPY

A significant number of patients with a chronic HBV infection do not need treatment. Whether someone with a hepatitis B infection needs treatment depends on a number of factors:

1. The severity of the liver damage: this is determined by a number of lab results and, possibly, by a liver biopsy or fibroscan.
2. The level of the hepatitis B virus in the blood (measured by PCR)
3. The type (genotype) of hepatitis B virus the patient has contracted. There are now 8 known genotypes (different appearances) of the hepatitis B virus: genotype A – H. In northern Europe, genotype A is the most common one.
4. The presence of an HIV infection in addition to the hepatitis B infection.
5. Possible pregnancy
6. Other illnesses or personal circumstances of the patient.

There are two groups of medications used for the treatment of a hepatitis B infection:

• Peginterferon (PEG-IFN)
• Nucleoside analogues: lamivudine, adefovir, entecavir, telbivudine

peginterferon
Peginterferon is administered once a week by a subcutaneous (under the skin) injection. The advantage of this treatment is that it gives a lasting response with some of the patients, meaning that the hepatitis B virus is suppressed, even when the treatment has been ceased. The treatment usually takes 48 weeks. The main disadvantages are adverse effects such as flu symptoms such as headaches, fatigue, and fever; low platelet count; and psychological problems such as a reduced ability to concentrate, irritation, and depression.

Nucleoside analogues
The advantage of the nucleoside analogues is the oral administration, fast reduction of the amount of HBV in the blood, and the fact that these medications hardly have any adverse effects. The disadvantage is that there usually is no lasting response, meaning that the medications must be taken for a very long time.

The choice of oral medication depends on the resistance of the hepatitis B virus and the presence of coinfections such as HIV. Of the currently available medications, entecavir has the most effective resistance profile, and entecavir and telbivudine have the largest antiviral potential.

Checkups
After starting the treatment, the checkups when using Peginterferon usually take place once a month, and when using nucleoside analogues, this is once every three months. The checkups usually involve a consultation and a blood test.

Injection or sex accidents
After an injection accident (when someone who is hepatitis B negative is injected with a contaminated needle) or a sex accident (when someone who is hepatitis B negative has unprotected sexual relations – consciously or due to a ripped condom – with someone who is hepatitis B positive), the physician or nurse can still give the vaccination and/or inject the ready-made antibodies (anti-hepatitis B immunoglobulin) against the hepatitis B virus within a very short period of time. All this must be done as quickly as possible, in any case within 24 hours. When you find yourself in such a situation, you need to contact the MC Jan van Goyen as quickly as possible (at 020-6622494). After office hours, the number will be redirected to the mobile phone of the internist on call. You can also go to the nearest ER department as quickly as possible.