1. What is Hepatitis B?
Hepatitis B is a liver disease caused by a virus.
This disease causes the liver to become inflamed and it ceases to function properly. This organ performs many important tasks, such as fighting against infections and bleeding or removing medication, drugs and other toxic substances from the bloodstream. It is also responsible for energy storage, progressively releasing it between meals or when needed.
2. What causes Hepatitis B?
Hepatitis B is caused by the Hepatitis B Virus (HBV), discovered in 1965.
It is the most dangerous type of hepatitis and it is one of the most common diseases in the world; there are an estimated 350 million chronic carriers of the virus. These carriers can develop serious liver disorders, such as cirrhosis and liver cancer, diseases responsible for the death of a million people a year across the globe; however, it is possible to prevent this virus through the hepatitis B vaccine, which has an efficiency of 95 per cent.
The virus causes acute hepatitis in a third of those affected, and one in every thousand infected may fall victim of fulminant hepatitis. In less than ten per cent of cases in which the infection occurs in adulthood, the disease becomes chronic, a situation more common in men. In Portugal, there are an estimated 150 thousand chronic carriers of HBV.
3. How can I contract Hepatitis B?
The virus is transmitted through contact with blood, semen and bodily fluids of an infect person, much like the human immunodeficiency virus (HIV), which causes Aids, only the Hepatitis B virus is 50 to 100 times more infectious than HIV.
There is also the possibility of mother to child transmission at birth, a particularly severe form of contagion, given the high tendency of evolution to chronicity. This is very common in hyperendemic areas of developing countries, where most of those infected contracts the virus during childhood. In industrialized countries, this age group is the most ‘secure’, as the vaccine against hepatitis B is part of the national program of vaccination of 116 countries, including Portugal.
In the Western world, Europe and North America, the virus is transmitted mainly to young adults through sexual contact and by sharing syringes and other injecting equipment among intravenous drug users.
In short, Hepatitis B can be contracted through:
- Having unprotected sex with infected people;
- Sharing syringes with intravenous drug users;
- Getting a tattoo or body piercing with dirty instruments or poorly sterilized ones which were previously used in other people;
- An accidental prick with a needle contaminated with infected blood (health care personnel can contract hepatitis B this way);
- Living with someone who has hepatitis B;
- Sharing personal objects (such as toothbrushes or razors) with an infected person;
Hepatitis B can’t be contracted through hugging, sitting next to or shaking hands with someone infected.
4. What are the symptoms of Hepatitis B?
Hepatitis B causes symptoms very similar to influenza, such as:
- Loss of appetite;
- Stomach pain;
Some people may also exhibit:
- Jaundice (skin and eyes present a yellowish colour);
- Light-coloured faeces;
- Dark-coloured urine.
Some people, however, may not present any symptoms.
5. Which tests are done to diagnose Hepatitis B?
To confirm if you are infected with the hepatitis B virus, the doctor orders lab blood tests. These tests serve not only to verify whether you are infected or not but also to identify the stage or course that the infection is taking at a given time.
There are 5 markers of Hepatitis B: 3 anti-bodies and 2 specific antigens. These markers appear in the blood at different times. Usually, the first to be detected is HBs antigen (HbsAg or Hepatitis B surface antigen), which persists for one to three months and which reveals the presence of the virus in the body. Its positivity is indicative of an acute or chronic active infection, or even that the patient is an asymptomatic carrier, potentially infectious.
A bit later (but sometimes simultaneously) the HBe (HBeAg) antigen arises, meaning that the infectious agent is multiplying. The risk of infection is higher at this stage.
Only after do the antibodies arise and the first to appear is, usually, anti-HBc (an antibody fighting HBcAg). It emerges in acute infections and chronic carriers, and it is an infallible marker of infection, more reliable than the surface antigen; afterwards, if the body’s immune defences are operating correctly, anti-HBe arises in response to the HBe antigen.
This means that there has been a seroconversion, the multiplication of the virus decreased and, if nothing interferes with the normal course, the HBs antigen disappears and the anti-HBs antibody arises, which remains in the body for a lifetime, and grants immunity. Its presence indicates the resolution of the disease and reflects immunity. It is an indicator of effective vaccination.
The presence of the HBe antigen, beyond eight weeks, indicates that the hepatitis is moving on to a chronic phase. The permanence of the HBs antigen for more than six months confirms the transition to the chronic stage.
The meaning and interpretation of these markers depend not only on each of them but in their joint presence or absence and their relationship with clinical data.
A liver biopsy may be needed for patients who exhibit evidence of virus presence in the body for more than six months, to assess the severity of liver damage. As chronic HBV infection is a sexually transmitted disease, infected people should be tested to detect the possible presence of HIV.
6. How is Hepatitis B treated?
Acute hepatitis B is treated with rest and the patient should not consume alcoholic beverages and foods or drugs that can be toxic to the liver.
If hepatitis evolves into a chronic disease, it can be treated with interferon. Pegylated interferon, or peginterferon, has replaced the classic interferon. The treatment with peginterferon lasts, in general, 12 months and has an efficiency of 36-42% or higher in patients with higher transaminases and lower viral load.
Alternatively, the treatment can be done with nucleoside analogues, such as lamivudine and adefovir, which interrupt the multiplication of the virus and stimulate the destruction of infected cells, meaning they have a strong antiviral effect but require a more prolonged administration than peginterferon to provide similar response rates.
As with all medication, treatments for hepatitis B have side effects, so patients should consult with a doctor. If chronic hepatitis leads to cirrhosis and this develops into liver failure, liver transplantation is advisable. However, in the case of hepatitis B, the risk of relapse is very high, since there are no effective ways to prevent infection in the new liver.
Normally, anti-HBs immunoglobulin is administered shortly after harvesting the liver from the body and before inserting the new organ, as to neutralize the virus in the blood. The patient should continue to receive anti-HBs immunoglobulin for several years, to prevent HBs antigen from reappearing.
The patient receiving the new liver should not be over 65 or suffer from a severe disease that affects other organs like the kidneys, lungs and heart.
7. How can I protect myself?
There is a vaccine against hepatitis B available to everyone, but it has no effect on those who are already infected by the virus. It consists of three doses that are administered via intramuscular injections within six months and shows an efficiency of 95 per cent. In Portugal, it is included in the National Vaccination Program. Babies, children of mothers carrying the virus, should be vaccinated at birth, after which there is no risk of transmission through breastfeeding.
It is necessary to get every injection to stay protected. If you are travelling to countries with a high incidence of hepatitis B, be sure to receive all injections before travelling.
Immunity appears to be lasting although limited in time, with no need for reinforcement, at least in the first five to ten years of vaccination.
Here are a few other measures against hepatitis B that you can take, to protect yourself and other people with whom you interact:
- Use condoms during sexual intercourse;
- Do not share used needles and syringes, sharp and piercing objects, or instruments used for the preparation of injectable drugs;
- Wear gloves and protective gear if you must be in contact with another person’s blood;
- Do not use someone else’s personal items of hygiene, which may contain traces of blood;
- Ensure that instruments used in tattoos, piercings or bodily perforations are clean and properly sterilized.
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