The main danger of hepatitis is that it is difficult to detect. A reliable method for determining hepatitis in humans is to find markers of viral hepatitis in the patient's blood. Thanks to their presence, the doctor can determine the type of hepatitis and the stage of the course of the disease, prescribe the appropriate treatment. From the article you will learn everything about the types of hepatitis, serological markers of viral hepatitis, the features of interpreting test results.
Hepatitis is a dangerous viral disease
Viral hepatitis is an inflammatory process in the liver caused by one of the 6 types of hepatitis (A, B, C, D, E and G). Infection with viruses occurs in different ways: hepatitis A and E - through water, household appliances and contaminated food, hepatitis B and C - through blood and other biological fluids. But hepatitis D is considered an additional infection that can occur ina person with another form of hepatitis.
Non-specific harbingers of infection are: anorexia, nausea, fever and pain in the right hypochondrium. Jaundice of the integument appears after the extinction of these symptoms. Acute hepatitis often becomes chronic, and as they progress, liver failure occurs. According to the World He alth Organization, 1.4 million people die every year from various forms of this viral infection in the world.
Characteristics of forms of hepatitis
Hepatitis A is caused by a single-stranded RNA virus. This is the most common form of hepatitis in children and adolescents and may be asymptomatic. It is transmitted enterally (fecal-orally). It does not become chronic. Vaccination and past illness form a strong immunity to this type of virus.
Hepatitis B is caused by a DNA virus. The most dangerous form, which can lead to death. Vaccination provides immunity to the virus. It is transmitted parenterally (blood and body fluids). The risk of perinatal transmission of the virus to the fetus from an infected mother is very high.
Hepatitis C is caused by an RNA virus that is transmitted parenterally. It becomes chronic in 75% of cases. There is no vaccine. There are several serotypes of this virus, the distribution of which varies geographically. Sexual or vertical (from mother to fetus) infection is very rare. May be asymptomatic even in the acute phase, becomes chronic withrelapses that can last for decades.
Hepatitis D is caused by an RNA-containing defective virus (delta agent) that can only replicate in the presence of the hepatitis B virus. It is transmitted parenterally via blood and body fluids.
The causative agent of hepatitis E is an RNA-containing virus. Transmission of infection is carried out by the enteral route. There are 4 serotypes that are especially dangerous for pregnant women in the second half of pregnancy. Can lead not only to the death of the fetus, but also to the death of the mother.
Hepatitis G is caused by an RNA-containing virus, which is more often combined with other types of hepatitis. In an independent form, it is asymptomatic. Infection occurs parenterally. Possible sexual transmission, vertical transmission of the virus from mother to fetus is likely.
Alcoholic hepatitis is also distinguished, which is associated with the intake of alcohol-containing drinks.
A special form of hepatitis is autoimmune. Its etiology is not clear. During the period of illness, antibodies are released into the blood that attack he althy hepatocytes. In 25% of cases, it is asymptomatic and is diagnosed only when it has already provoked cirrhosis of the liver.
Features of infection
In 40% of cases of hepatitis, the source of infection remains unclear. Through enteral transmission of the virus, hepatitis can be contracted from public transport, banknotes, and other public items.
Possible infection through unprotected sexual contact. People in this risk group are advised to be tested forhepatitis every 3 months.
About 2% of donated blood may contain hepatitis viruses.
Piercings, tattoos, manicures and pedicures can also cause infection if instruments are not properly sterilized.
Vertical transmission of infection from an infected mother to her fetus is rare. Only the acute form of hepatitis in the third trimester of pregnancy is considered very dangerous for the fetus. Infection of the child during childbirth is unlikely.
Acute disease
Most often, hepatitis occurs in an acute form. During the course of the disease, the following periods are distinguished:
- Incubation. The virus spreads in the body but does not cause symptoms.
- Prodromal (preicteric). Nonspecific symptoms appear: nausea, vomiting, fever, pain in the right hypochondrium.
- Icteric. On the 10th day of the course of the disease, the urine becomes dark, and the skin and mucous membranes become yellow. The liver is enlarged, painful on palpation.
- Restorative. At 4-8 weeks after infection, jaundice disappears and hepatitis resolves spontaneously.
WHO activities
The statistics are relentless - 0.5 billion people in the world have a chronic form of hepatitis B and C. About 57% of liver cirrhosis and 8% of primary liver cancer are caused by chronic hepatitis.
Hepatitis infection can be prevented by water and food safety (hepatitis A and E), vaccination (hepatitis A, B, E), screeningdonors, infection control and sterility of injection equipment (hepatitis B and C).
The World He alth Organization in 2011 approved the Global Hepatitis Program, and July 28 established the World Day against this dangerous disease. Since 2014, this program has been part of the tuberculosis, HIV-AIDS, malaria and other tropical diseases cluster.
Why get tested?
Prophylactic tests for hepatitis are of great importance due to the asymptomatic onset of the disease. For diagnosis, one or more markers are used, which determine not only the presence of infection, but also the stage of the course of the disease.
It is necessary to take into account the general epidemiological situation in the region of residence. Especially for those types of hepatitis that can be transmitted through water and domestic contact.
Treatment in the early stages of the disease gives positive dynamics and a complete cure.
What is a marker?
Marker refers to specific substances in the blood that are produced in response to an attack by pathogens. Viral hepatitis markers can be:
- Antibodies that are produced by blood leukocytes against viral particles.
- Proper viral antigen proteins.
- Specific markers of viral hepatitis, which are analyzed during blood sampling.
- Fragments of nucleic acids (DNA and RNA) of the hepatitis virus itself.
In clinical studies of the patient's blood, the following markers of viral hepatitis are determined: A, B, C, D, E andG.
How is it done?
Taking blood for markers of viral hepatitis is a simple procedure. Blood is taken from the cubital vein. It is advisable to take the test in the morning and on an empty stomach. In pregnant women, blood sampling for this analysis is possible at any time. In addition, at any time, blood for markers of viral hepatitis is taken upon admission to the hospital and in preparation for surgical operations.
It is desirable to do the analysis for people who belong to the risk group - injection drug addicts, with promiscuity (promiscuity) and unprotected sex. Blood sampling for markers of viral hepatitis and the algorithm for its implementation is standard.
Viral hepatitis A
This type of hepatitis is the most common, occurs mostly without complications, sometimes passing spontaneously or with minimal treatment.
A blood test for markers of viral hepatitis A is prescribed in the following cases:
- When clinical manifestations of hepatitis appear.
- When yellowness of the integument and mucous membranes appears.
- With an increase in the protein-enzyme aspartate aminotransferase (AsAt), which is produced in the liver, in the blood.
- When in contact with an identified patient.
- If there are foci of infection, an analysis for hepatitis markers is carried out in all contact persons.
- When establishing immunity to viral hepatitis A during vaccination.
Interpretation of test data for viral hepatitis A markers:
- A negative result indicatesabout the lack of immunity to this virus in the patient.
- Positive result: antibodies of immunoglobulin M (IgM) to this type of hepatitis were detected - the acute phase of the disease is underway; the detection of IgG antibodies to this type of hepatitis indicates that the body has already met with this viral infection and is immune to it; detection of hepatitis A antigens and RNA virus - the presence of the virus in the body.
Hepatitis group B
This type of hepatitis is the world's biggest public he alth problem. Hepatitis B virus - DNA-containing, leads to acute and chronic course of the disease with damage to liver cells, up to death.
Research for markers of viral hepatitis B is prescribed:
- In preparation for vaccination and confirmation of its effectiveness.
- When detecting antigens of viral hepatitis B in the blood and with clinical manifestations of the disease.
- When the level of AsAt protein in the blood increases.
- In the presence of chronic pathologies of the liver, bile ducts.
- For focal infections.
- In preparation for parenteral manipulation, hospitalization.
- When planning pregnancy and if there is one.
- When screening blood donors.
- When belonging to a risk group (unprotected sex, promiscuity, injecting drugs).
The absence of markers in the blood indicates that the patient is not immune to this virus.
Detection of the following markers of viral hepatitis B is interpreted as follows:
- Antigens in the blood(HBsAg) - the presence of an acute or chronic form of the disease, virus carriers.
- IgM antibodies - previous infection or vaccination consequences.
- IgG antibodies - past illness.
- HBeAg and Pre-S1 – high infectivity, active virus replication, risk of perinatal transmission.
- Pre-S2 - the presence of one form of hepatitis B.
- Pre-S2 Antibodies – recovery from illness.
- DNA polymerase and virus DNA - the presence of hepatitis B and active replication of the virus.
Hepatitis C
The peculiarity of this form of hepatitis is a frequent course without jaundice and in a mild form. In the absence of diagnosis in the early stages, it becomes chronic with the appearance of cirrhosis and malignant tumors in the liver.
A blood test for markers of viral hepatitis C is carried out:
- When the level of AlAs increases.
- In preparation for operations and parenteral manipulations.
- When planning a pregnancy.
- For clinical manifestations of hepatitis.
- When belonging to a risk group (unprotected sex, promiscuity, injecting drugs).
The absence of hepatitis C markers in the patient's blood indicates the absence of infection or the incubation period (4-6 weeks). Markers are also absent in seronegative hepatitis C.
Deciphering markers of viral hepatitis C:
- Hepatitis C IgM antibodies are the active phase of virus replication.
- IgG antibodies to this type of hepatitis - the presence of a virus is possible, or has already beenencounter with the virus.
- Antigens of the virus or its RNA - the presence of viral hepatitis C.
Viral hepatitis D
RNA-containing virus of this form of hepatitis coexists with hepatitis B, significantly aggravating its course. An examination for markers of viral hepatitis D is carried out in the diagnosis of this disease and in the diagnosis after treatment.
The absence of markers means that the virus was not detected in the blood.
Positive markers:
- IgM antibodies to this form of hepatitis is an acute stage of the disease with active virus replication.
- Hepatitis D virus IgG antibodies - a past encounter with the virus.
- Hepatitis D virus antigens or its RNA - presence of infection.
Hepatitis E
In terms of symptoms and clinical picture, it is similar to hepatitis A. It is especially dangerous during pregnancy - it causes gestosis of the last trimester with a triad of symptoms: edema (external and internal), proteinuria (protein in the urine), hypertension (high blood pressure). In a severe form of the course, a fatal outcome is possible for both the fetus and the mother.
In addition, the analysis is prescribed:
- For severe symptoms of hepatitis.
- Those who have had blood transfusions or hemodialysis.
- Injection drug addicts.
- Persons from endemic areas.
- When assessing the effectiveness of vaccination.
The absence of markers indicates the absence of immunity to this type of hepatitis.
The presence of antibodies - IgM immunoglobulins to hepatitis E indicatesacute stage of the disease, IgG antibodies - immunity is due to a previous encounter with the hepatitis E virus, antigens or RNA of the virus indicate the presence of infection.
Hepatitis type G
This type of hepatitis is similar in symptoms and clinical picture to hepatitis C, often occurs together with hepatitis B and D.
Indications for analysis are the diagnosis and monitoring of the disease.
A negative result indicates the absence of immunity, and the detection of antigens indicates a previous meeting and the presence of immunity. Detection of an RNA virus in the blood indicates the presence of the virus and its active replication.
