Hepatitis B causes an acute infection of the liver that, depending on the patient’s immune status, can become chronic and progress to liver cirrhosis (usually within five years) or liver cancer (hepatocarcinoma).
HBV infection in highly endemic countries is responsible for up to 90% of liver cancers, which in developing countries is almost always fatal; however, in high-income countries, surgery and chemotherapy can increase life expectancy.
The probability that Hepatitis B will go from acute to chronic depends mainly on the age at which the disease is contracted.
In adults, the disease can become chronic in about 5-10% of cases, while 9 out of 10 times hepatitis B becomes chronic in infected babies shortly after birth.
Hepatitis B is most common in sub-Saharan Africa and East Asia. High rates of chronic infections are also found in the Amazon, Eastern Europe, and Central Europe.
It is also estimated that in the Middle East and the Indian subcontinent, between 2% and 5% of the general population have a chronic infection, compared to less than 1% of the population in Western Europe and North America.
Signs and symptoms of hepatitis B
Hepatitis B has an incubation period of 45 to 180 days during which the first symptoms may appear, although in most cases, and especially in children, hepatitis B is completely asymptomatic.
However, when symptoms are present, malaise, fever, fatigue, nausea and vomitingand musculoskeletal pain is noted.
Sometimes jaundice, dark-colored urine, and light-colored stools may appear.
Rarely, liver failure, kidney problems, pancreatitis, and neuropathy.
Causes and transmission of Hepatitis B
The source of Hepatitis B infection are people with acute disease or chronic carriers, who present the virus in the blood, but also in other biological fluids: saliva, bile, nasal secretions, breast milk, semen, vaginal mucus, etc.
- through the blood by apparent parenteral route (transfusion of blood or blood products in underdeveloped countries, cuts and punctures with needles and infected instruments) or non-apparent parenteral route (injuries to the skin or mucous membranes by toothbrushes, scissors, combs and contaminated brushes, or instruments that have not been properly sterilized)
- sexually (semen, cervical mucus)
- through biological fluids (bile, nasal secretion)
- from mother to child at birth and through breast milk.
The hepatitis B virus is very resistant and can survive in external environments such as dried blood for up to 7 days.
Therefore, contagion is possible both through contact with the sick person and through contact with contaminated objects.
The person sick with Hepatitis B is contagious in the acute phase.
The person with chronic disease (chronic carrier of HBV) remains infectious for life.
Who is at risk of contracting the hepatitis B virus
Although anyone can get sick, certain categories of people are at higher risk of coming into contact with the Hbv virus.
- those who engage in unprotected sex with multiple partners
- drug addicts
- relatives and people in contact with infected people
- children born to infected mothers
- laboratory staff and workers who are exposed to blood and/or may handle needles and syringes if they are not perfectly sterilized
- those who practice and perform piercings, manicures, pedicures
- hemodialysis patients
- those traveling to countries where the virus is particularly widespread.
Since the introduction of vaccination in Italy in 1991, new cases of hepatitis B have been reduced by 80%.
Screening of blood donors has also reduced the chance of contracting the infection through transfusions.
The diagnosis of Hepatitis B is made by detecting markers (Ag) and antibodies (Ab) in the patient’s blood:
- HBsAg, the surface antigen that indicates the state of infection. All people who test positive for HBsAg are considered potentially infectious.
- HBsAb, is the antibody against the surface antigen. Its presence indicates immunization and is found after recovery from infection or after vaccination.
- HBcAb-IgM, the antibody found in the replication phases of the virus. It is positive in both the acute and relapsing chronic forms.
- HBcAb-IgG, the antibody that indicates contact with the virus. It remains positive throughout life regardless of the outcome of the infection.
- HBeAg is found in the early phase of acute hepatitis and in some forms of chronic hepatitis.
- HBeAb, the antibody directed against HBeAg. Its presence does not prevent evolution to the chronic form.
- Hbv-DNA, the virus genome that always indicates infection activity. By definition, the healthy carrier will always be Hbv-DNA negative.
- HBcAg: it is the antigen of the central part of the virus, the only marker that is only found in liver cells and never in the blood.
Hepatitis B therapies
For acute hepatitis B, there is no specific therapy.
The goal of treatment is largely to improve the patient’s quality of life and long-term survival by supporting proper nutritional balance, preventing disease progression to cirrhosis, and reducing the incidence of hepatocellular carcinoma.
To help the healing process, patients with Hepatitis B are recommended to rest and follow a light diet (low in fat but rich in fluids, sugars and proteins) and avoid alcohol consumption.
If you suspect that you have come into contact with the Hbv virus, it is important to seek medical attention immediately.
Treatment with specific immunoglobulins administered within 24 hours of infection, combined with subsequent booster vaccination, may protect the patient from developing infection.
How to prevent hepatitis B
The hepatitis B vaccine is the cornerstone of prevention.
The World Health Organization recommends that all children receive the hepatitis B vaccine as soon as possible after birth.
It is highly recommended for population groups at higher risk of coming into contact with the virus.
It is given by intramuscular injection, in the arm for adolescents and adults, and in the thigh for infants.
Side effects are rarely reported, and when they do occur, they tend to be primarily local at the injection site (itching, mild swelling, pain).
A feeling of general malaise and the onset of fever, headache and bone/joint pain may occur.
The vaccine protects against the virus for 10-15 years.
To check the real coverage, it is enough to check the presence and titer of Anti-HBs with a simple blood test.
It is contraindicated for people with a known allergy to the components of the vaccine.
It is also important, in the case of Hepatitis B, to inform the partner of the infection and recommend that he or she be tested.