Epstein-Barr virus
The content of the article:
- The mechanism of infection and ways of infection
-
Symptoms of the Epstein-Barr virus
- Infectious mononucleosis
- Chronic fatigue syndrome
- Generalized Epstein-Barr infection
- Diagnostics
- Epstein-Barr virus treatment
- Potential consequences and complications
- Forecast
- Prevention
Epstein-Barr virus (human herpes virus type IV, Epstein-Barr virus, EBV, human herpesvirus type IV) is a member of the herpevirus family of the gammherpesvirus subfamily. It can replicate in lymphocytes, cells of the immune and central nervous system, the mucous membrane of the upper respiratory tract, and internal organs. The Epstein-Barr virus, unlike other herpeviruses, does not lead to the death of infected cells, but, on the contrary, promotes their active reproduction (proliferation).
Epstein-Barr virus
The Epstein-Barr virus is widespread in the population. According to the WHO, more than 90% of people, including infants, are carriers of it. However, it is still not well understood.
Infection with the Epstein-Barr virus leads to the development of a latent infection, that is, the carrier of viruses, which can last throughout a person's life, without manifesting itself clinically. However, against the background of a general decrease in immunity, the virus is able to activate and cause the development of a number of diseases.
The mechanism of infection and ways of infection
The source of infection is a person with an active form of the Epstein-Barr virus, infectious from the last days of the incubation period and for 6 months. According to medical statistics, about 20% of people who have had an active form of infection remain spreading the infection for many years.
The risk group for infection with the Epstein-Barr virus includes:
- pregnant women;
- children under the age of 10;
- patients with immunodeficiencies of various origins;
- HIV positive persons.
Pregnant women are at risk of contracting the Epstein-Barr virus
The Epstein-Barr virus can be transmitted from person to person in the following ways:
- contact and household (through kisses, personal hygiene items, common towels, toys, dishes);
- airborne droplets (when coughing, sneezing or talking);
- transmissible (with transfusion of blood and its components, organ and bone marrow transplantation);
- vertical (from mother to child during pregnancy, childbirth or breastfeeding);
- alimentary (through food and water).
When infected, the Epstein-Barr virus enters the cells of the mucous membrane of the mouth, upper respiratory tract, salivary glands or tonsils. Here it begins to actively multiply, and then the virions with the blood flow enter the cells of other organs and tissues.
The defeat of the virus of B-lymphocytes is accompanied by an increase in their population. This triggers the activation of T-lymphocytes, which begin to attack the affected immune cells. Clinically, this process is manifested by an increase in all groups of lymph nodes.
With a normally functioning immune system, infection with the Epstein-Barr virus may not show any clinical symptoms, which is associated with the presence of formed immunity to various types of herpes simplex viruses. But in some cases, infection leads to the development of an acute infectious process called infectious mononucleosis (Filatov's disease). It is accompanied by the active production of immunoglobulins capable of retaining the Epstein-Barr virus in B-lymphocytes for many years. Filatov's disease in many cases remains undiagnosed due to an erased course or is mistakenly regarded by doctors as a respiratory viral infection.
If a person has good immunity, the Epstein-Barr virus may not show up for years
With low immunity of the patient, especially with an insufficient number of T-lymphocytes, a latent chronic infection is formed that does not have external signs.
Against the background of a significant deficiency of T-lymphocytes, patients may develop a generalized pathological process, in which the virus infects the heart, spleen, liver, and central nervous system. Therefore, this infection is of particular danger for people with HIV infection (especially at the AIDS stage), since they have a sharp decrease in the number of T-lymphocytes.
In the chronic latent course of infection, any decrease in the functions of the immune response contributes to the activation of the Epstein-Barr virus and creates the preconditions for the emergence of a number of diseases associated with it:
- toxic hepatitis;
- viral or bacterial (due to the addition of a secondary infection) pneumonia;
- a decrease in the number of platelets in the blood, manifested by a tendency to hemorrhage;
- meningitis;
- chronic fatigue syndrome;
- malignant neoplasms (cancer of the intestine, stomach, esophagus, tonsils, nasopharynx, as well as Burkitt's lymphoma, Hodgkin's disease);
- autoimmune diseases (rheumatoid arthritis, autoimmune hepatitis, systemic lupus erythematosus, type I diabetes mellitus, multiple sclerosis).
When conducting a study of biopsy material obtained from cancer patients, the Epstein-Barr virus is found in about 50% of samples. By itself, it does not have the ability to induce the formation of tumor cells, but is able to enhance the action of other carcinogenic factors.
The development of autoimmune diseases against the background of infection with the Epstein-Barr virus has the following explanation: the virus, together with other pathogenic microflora, distorts the immune response, which causes the immune system to recognize its own tissues as foreign and actively damage them.
Against the background of the chronic course of the infection, many patients eventually develop a common variable immune deficiency. Clinically, it manifests itself in frequent infectious diseases, which are characterized by a long and severe course. An insufficiently formed immune response leads to the fact that patients may experience repeated cases of rubella, chickenpox, measles and other infectious diseases, to which a stable immunity should normally be formed. Bacterial infections are also more severe than usual and can be complicated by the development of septic conditions.
Dysfunctions of the immune system by the Epstein-Barr virus can cause the development of severe, generalized allergic reactions (Stevens-Jones syndrome, Lyell's syndrome, erythema).
Symptoms of the Epstein-Barr virus
The clinical symptoms of Epstein-Barr virus are polymorphic, which is explained by the many diseases it causes.
Infectious mononucleosis
Infectious mononucleosis is one of the most common infections caused by the Epstein-Barr virus in children. The incubation period for this disease lasts 4-15 days. After its completion, the patient's body temperature rises sharply to 38-40 ° C, which is accompanied by chills. At the same time, intoxication symptoms also occur (a sharp deterioration in general well-being, headache and muscle pain, a feeling of weakness, lack of appetite). A few hours later, flu-like symptoms join: patients begin to complain of sore throat and nasal congestion. Approximately 85% of patients experience enlarged lymph nodes on days 5–7 of the disease. The manifestations of lymphadenitis persist until the end of the peak period of infectious mononucleosis. Some patients may have hepatosplenomegaly (enlargement of the spleen and liver).
Infectious mononucleosis is the most common Epstein-Barr virus infection
Epstein-Barr virus in infants causes an erased clinical picture of infectious mononucleosis. The older the child, the more pronounced the symptoms of the disease.
Chronic fatigue syndrome
In chronic fatigue syndrome (CFS), fatigue, malaise, a feeling of general weakness and a decrease in working capacity are constantly observed in the patient and do not disappear even after a good rest.
CFS most often affects young and middle-aged people. Its main features:
- constant feeling of tiredness;
- muscle weakness;
- body aches;
- headaches;
- sleep disturbances (difficulty falling asleep, nightmares, frequent waking up at night);
- flu-like symptoms (nasal congestion, sore throat, low-grade fever);
- mental disorders (labile mood, disappointment in life, indifference to the environment, psychosis, depressive states);
- decreased concentration of attention;
- forgetfulness.
The development of CFS is explained by the effect of the Epstein-Barr virus on the brain, which leads to prolonged overexcitation of neurons in the cortex, and then to their depletion.
Doctors explain chronic fatigue syndrome by Epstein-Barr virus
Generalized Epstein-Barr infection
The generalized course of infection is usually observed in people with severely weakened immunity, for example, in patients with AIDS or undergoing red bone marrow transplantation, collected from a donor carrying the Epstein-Barr virus.
The disease begins with signs of infectious mononucleosis, however, after a short time, symptoms are added to them, indicating the defeat of almost all vital organs:
- central nervous system (cerebral edema, meningitis, encephalitis);
- cardiovascular system (endocarditis, myocarditis, cardiac arrest);
- lungs (respiratory failure, interstitial pneumonia);
- liver (toxic hepatitis with symptoms of liver failure);
- blood (DIC syndrome, coagulopathy);
- kidney (acute renal failure in the presence of severe nephritis);
- the spleen (a significant increase in its size, leading to a high risk of rupture);
- lymphatic system (acute proliferative syndrome).
Generalization of the infection caused by the Epstein-Barr virus is often fatal.
Diagnostics
Diagnostics of the infectious process caused by the Epstein-Barr virus is carried out in the laboratory, using serological research methods, which are based on the detection of specific antibodies to viral proteins. In clinical practice, the Henle reaction (the reaction of indirect immunofluorescence) is most often used, with the help of which antibodies (IgM, IgG, IgA) are determined to capsid, non-capsid early and nuclear antigens. Diagnostic titers of specific antibodies are usually detected 15-30 days from the onset of the disease.
To diagnose the Epstein-Barr virus, it is necessary to identify IgM, IgG, IgA antibodies in a blood test
Titers of IgM and IgG to capsid antigens reach their maximum at 3-4 weeks of illness. Then there is a sharp decrease in the IgM titer, and after 3 months it becomes impossible to determine them. IgG titers are also gradually decreasing, but in small amounts I circulate in the patient's blood throughout his life.
Persistence of IgG in high titers can be observed with a long course of the infectious process, against the background of chronic renal failure, Burkitt's lymphoma, nasopharyngeal carcinoma, Hodgkin's lymphoma, HIV infection, immunodeficiency states and rheumatoid arthritis.
In the first 2-3 months of the disease, antibodies to early antigens are detected in the blood of 80-90% of patients. In about 20% of cases, they can be detected in patients with a chronic variant of the course of the infectious process. High titers of these antibodies are observed in pregnant women, as well as in patients with cancer and HIV carriers.
Antibodies to nuclear antigens begin to be detected two months after infection with the Epstein-Barr virus. They persist in low titers, and their absence suggests a violation of the patient's immune status.
In the acute course of Epstein-Barr infection, characteristic changes in the blood picture are also noted:
- leukocytosis;
- lymphocytosis;
- monocytosis;
- hypergammaglobulinemia;
- thrombocytopenia;
- increased concentration of bilirubin;
- the appearance of cryoglobulins;
- the presence of at least 80% of atypical mononuclear cells (precursor cells of cytotoxic T-lymphocytes that destroy virus-infected B-lymphocytes).
Diseases caused by the Epstein-Barr virus require differential diagnosis with a number of other pathological conditions, primarily with the following diseases:
- listeriosis;
- leukemia;
- toxoplasmosis;
- viral hepatitis;
- viral tonsillitis;
- streptococcal pharyngitis;
- rubella;
- diphtheria;
- adenovirus infections;
- cytomegalovirus infection.
Epstein-Barr virus treatment
Currently, there is no consensus among specialists regarding the treatment regimen for Epstein-Barr viral infection.
With infectious mononucleosis, patients are hospitalized in an infectious diseases hospital. In the acute period, in addition to the main therapy, they are prescribed a half-bed regimen, abundant drinking and dietary food. Sweet, salty, smoked and fatty foods are excluded from the diet. Food should be taken frequently, in small portions. The menu must include fermented milk products, fresh vegetables and fruits.
For chronic fatigue syndrome, general guidelines are:
- taking a complex of multivitamins with minerals;
- good balanced nutrition;
- positive emotions;
- regular sports;
- long walks in the fresh air;
- normalization of sleep;
- observance of the regime of alternation of work and rest.
In the treatment of the Epstein-Barr virus, the patient is prescribed immunoglobulins
If necessary, medical treatment of the Epstein-Barr virus is carried out. It is aimed at eliminating the symptoms of the disease, increasing immunity, preventing or treating possible complications. For this, drugs of the following groups are used:
- immunoglobulins - drugs that contain ready-made antibodies that can bind the Epstein-Barr virus and remove it from the body. Most effective in the acute period of the Epstein-Barr viral infection, as well as in exacerbations of a chronic infectious process. Introduced intravenously in a hospital setting;
- drugs that suppress the activity of DNA polymerase - are prescribed for patients with a generalized form of infection, as well as for malignant neoplasms associated with the Epstein-Barr virus. In acute infectious mononucleosis, they do not have the necessary therapeutic effect;
- drugs that have an immunostimulating and / or nonspecific antiviral effect - in severe infectious mononucleosis and during exacerbations of a chronic infectious process;
- antibiotics - are indicated when a secondary bacterial infection is attached. Patients with infectious mononucleosis should not be prescribed penicillin drugs;
- non-steroidal anti-inflammatory drugs - indicated for the relief of fever, headache and muscle pain. Aspirin (acetylsalicylic acid) is not recommended due to the high risk of Reye's syndrome;
- glucocorticosteroids - indicated for generalized Epstein-Barr infection or severe infectious mononucleosis;
- hepatoprotectors - help to restore liver cells and improve their functions. Prescribed when the patient develops toxic hepatitis;
- antihistamines - have antiallergic effect, their appointment during the height of infectious mononucleosis helps to reduce the risk of complications;
- vitamins - shorten the period of convalescence of infectious mononucleosis, improve the general condition of patients with chronic fatigue syndrome.
With severe CFS, antiviral and vascular agents, antidepressants, sedatives, multivitamins, nootropics are included in the drug therapy regimen.
Potential consequences and complications
Infections caused by the Epstein-Barr virus can lead to the development of a number of complications:
- urticaria, dermatitis;
- erythema multiforme;
- monoarthritis;
- mumps;
- orchitis;
- meningitis;
- uveitis, optic neuritis;
- episcleritis;
- nephritis;
- hepatitis and liver necrosis;
- pneumonia, pleurisy;
- myocarditis, pericarditis;
- malabsorption;
- acute psychosis;
- Guillain-Barré syndrome (acute autoimmune polyneuropathy);
- transverse myelitis;
- Reye's syndrome (one of the variants of acute hepatic encephalopathy);
- hemolytic uremic syndrome;
- aplastic anemia;
- ruptured spleen.
Forecast
The existing therapy for Epstein-Barr infection does not allow the patient to recover completely, the virus remains in the patient's B-lymphocytes for life. With a weakening of the immune system, the virus is able to activate, which leads to an exacerbation of the infectious process, and in some cases the development of cancer.
Prevention
There are no primary preventive measures to prevent infection with the Epstein-Barr virus. It is believed that most adults are virus carriers, therefore, measures aimed at strengthening the immune system are important, which prevent the occurrence of exacerbations, i.e., secondary prevention. These measures include:
- balanced diet;
- rejection of bad habits (smoking, alcohol abuse);
- regular, but moderate physical activity;
- adherence to the daily regimen (a full night's rest is especially important);
- hardening procedures;
- avoidance of stress, mental and physical overload;
- timely diagnosis and active treatment of any somatic and infectious diseases.
YouTube video related to the article:
Elena Minkina Doctor anesthesiologist-resuscitator About the author
Education: graduated from the Tashkent State Medical Institute, specializing in general medicine in 1991. Repeatedly passed refresher courses.
Work experience: anesthesiologist-resuscitator of the city maternity complex, resuscitator of the hemodialysis department.
The information is generalized and provided for informational purposes only. At the first sign of illness, see your doctor. Self-medication is hazardous to health!
