EBV ( Epstein -Barr virus infection or EBV infection ) - Causes, Symptoms and Treatment .MF .

August 12, 2017 17:52 | Infectious Diseases

Epstein-Barr virus infection (EBVI) is one of the most common human diseases.According to WHO, the virus Epstein-Barr virus infected about 55-60% of young children (under 3 years), the vast majority of the planet's adult population (90-98%) have antibodies to EBV.The incidence in different countries ranges from 3-5 to 45 cases per 100 thousand. Population is quite high.EBVI refers to a group of uncontrollable infections for which there is no specific prophylaxis (vaccination), which, of course, affect the incidence.

Epstein-Barr virus infection - acute or chronic infectious human disease caused by the Epstein-Barr virus of the herpes family of viruses (Herpesviridae), having a favorite feature of lymphoreticular lesions and immune systems.

Pathogen EBVI

Epstein-Barr virus (EBV) - this DNA virus from the family of the Herpesviridae (gamma-herpesviruses) is a herpesvirus type 4.For the first time detected from cell lymphoma Burkett about 35-40 years ago.
virus has a spherical shape with a diameter

up to 180 nm.The structure consists of 4 components: core, capsid, the inner and outer shell.The core comprises a DNA consisting of 2 yarns comprising up to 80 genes.On the viral particle surface also contains dozens glycoprotein required for the formation of neutralizing antibodies.The viral particle contains specific antigens (proteins required for diagnosis):
- capsid antigen (VCA);
- early antigen (EA);
- nuclear or nuclear antigen (NA or EBNA);
- membrane antigen (MA).
significance of, the timing of their appearance in various forms EBVI not the same and has a specific meaning.

EBV

Epstein-Barr virus is relatively stable in the environment, quickly killed by drying, exposure to high temperatures, as well as common action disinfected vehicles.In biological tissues and fluids of the Epstein-Barr virus can positively feel if it enters the blood from the patient EBVI, brain cells completely healthy person, cells in cancer processes (lymphoma, lekemiya and others).

virus has a certain tropism (predilection for favorite cell):
1) tropism for cells lymphoreticular system (there is lymph node involvement of any group, enlarged liver and spleen);
2) tropism for cells of the immune system (the virus replicates in B-lymphocytes, which can be maintained for life, by virtue of which violated their function and there is immunodeficiency);In addition to lymphocytes, in EBVI disrupted and cellular immunity (macrophages, NK - natural killer cells, neutrophils, and others), which leads to lower total body resistance to various viral and bacterial infections;
3) tropism for epithelial cells of the upper respiratory tract and digestive tract , whereby children can occur respiratory syndrome (cough, shortness of breath, "false croup"), diarrheal syndrome (loose stools).

Epstein-Barr virus has allergenic properties , which is manifested by certain symptoms in patients with 20-25% of patients have an allergic rash in some patients may develop angioedema.

Particular attention is drawn to this property of the virus Epstein-Barr as « lifelong persistence in the body ».Due infected B-lymphocytes of the immune system data cells acquire the ability to unlimited life activity (so-called "cellular immortality") and constant synthesis of heterophilic antibodies (autoantibodies, or, for example, antinuclear antibodies, rheumatoid factor, cold agglutinin).In these cells, and EBV lives constantly.

currently known strains 1 and 2, Epstein-Barr virus, which do not differ serologically.

Causes of Epstein-Barr virus infection

source of infection when EBVI - ailing symptomatic form and virus carrier.The patient becomes infectious in the last days of the incubation period, the initial period of the disease, the height of the disease, as well as the whole period of convalescence (up to 6 months after recovery), and up to 20% recover retain the ability to periodically shed virus (ie, remain carriers).

mechanisms of infection EBVI:
- it aerogenic (airborne route of transmission), in which the contagious saliva and mucus in the oropharynx, which is released when sneezing, coughing, talking, kissing;
- contact mechanism (contact-household transmission path), in which there is or licks household items (dishes, toys, towels, etc.), but due to the instability of the virus in the environment is unlikely value;
- allowed transfusion mechanism of infection (transfusion of infected blood and blood products);
- nutritional mechanism (water and food pathway);
- now proven mechanism of transplacental infection of the fetus with congenital development EBVI.

Susceptibility to EBVI: infants (under 1 year) suffer from Epstein-Barr virus infection is rarely due to the presence of passive maternal immunity (maternal antibodies) are most susceptible to infection and the development of clinically significant forms EBVI - children from 2 to 10 years.

Despite the variety of modes of transmission of the population has a good immune layer (up to 50% of children and 85% adults): Many of the infected carriers without developing symptoms, but with the development of immunity.It is therefore considered that the environment for the patient EBVI malozarazno disease since many already have antibodies to the Epstein-Barr virus.

Rarely in closed institutions (military units, dormitories) can still be observed flash EBVI that low intensities on the severity and stretched in time.

For EBVI, and in particular its most frequent manifestation - mononucleosis - characteristic of the spring-autumn season.
Immunity after past infection formed a lasting, lifelong.Ill re acute EBVI impossible.Repeated cases of the disease are associated with the development of recurrent or chronic form of the disease and its relapse.

Way Epstein-Barr virus in the human body

Entrance gate infection - the mucous membrane of the rotor and the nasopharynx, where the multiplication of the virus and the organization of non-specific (primary) protection.At the end of the initial infection is influenced by the general immunity, concomitant diseases, infection status of the input gate (yes or no chronic diseases rotor and nasopharynx) and infectious dose and virulence of the pathogen.

Outcomes primary infection may be: 1) reorganization (the destruction of the virus in the input gates);2) subclinical (asymptomatic form);3) clinically defined (manifest) form;4) primary latent form (in which the reproduction of the virus and its allocation possible, but no clinical symptoms).

Next entrance gate of infection, the virus enters the blood (viremia) - the patient may be temperature and intoxication.At the site of the entrance gate is formed "primary focus" - catarrhal sore throat, shortness of nasal breathing.Further there is a drift of the virus in a variety of tissues and organs with primary liver injury, spleen, lymph nodes and other.It was during this period in the blood appear "abnormal tissue mononuclear cells" against the background of a moderate increase in lymphocytes.

atypical mononuclear cells in the blood

outcome of the disease may include: healing, chronic EBV - infection, asymptomatic carriage, autoimmune diseases (systemic lupus erythematosus, rheumatoid arthritis, Sjogren's syndrome and other) cancer, for cancer andcongenital EBV infection - possibly fatal.

Symptoms of EBV infection

Depending on the climate is dominated by these or other clinical forms EBVI.In temperate countries, which include the Russian Federation, it is more common infectious mononucleosis, and if there is no immunity deficiency can develop subclinical (asymptomatic) disease.Also, Epstein-Barr virus may be the cause of "chronic fatigue syndrome", autoimmune diseases (rheumatoid disease, vasculitis, ulcerative colitis).In countries with tropical and subtropical climates may develop malignant tumors (lymphosarcoma Burkitt, nasopharyngeal carcinoma, and others), often with metastases in various organs.In HIV-infected patients is associated with the occurrence of EBVI hairy leukoplakia of tongue, brain lymphoma, and other manifestations.

Currently clinically proven fact directly related Epstein-Barr virus with the development of acute mononucleosis, chronic EBVI (or EBV infection), congenital EBV infection, "chronic fatigue syndrome", lymphoid interstitial pneumonia, hepatitis, cancer, lymphoproliferative disease (lymphomaBurkitt, T-cell lymphoma, nasopharyngeal carcinoma, or NFC, leiomyosarcoma, lymphoma nehodzhinskie), HIV-associated diseases ( "hairy leukoplakia" brain lymphoma, common neoplasm of lymph nodes).

details about some manifestations of EBV infection:

1. Infectious mononucleosis , which manifests itself as an acute form of the disease with cyclical and specific symptoms (fever, catarrhal sore throat, shortness of nasal breathing, increase in groups of lymph nodes, liver, spleen, allergicrash, specific changes in the blood).For more information - see the article "infectious mononucleosis"..
Adverse in terms of chronic EBV infection symptoms:
- protracted course of infection (long low-grade fever - 37-37,5 ° - to 3-6ti months, saving more enlarged lymph nodes 1,5-3h months);
- the occurrence of relapses with the resumption of symptoms during 1,5-3-4h months after an initial attack of illness;
- preservation of IgM antibodies (to EA, VCA antigens EBV) for more than 3 months after the onset of the disease;no seroconversion (seroconversion - the disappearance of antibodies IgM and IgG antibody formation to different antigens of Epstein-Barr virus);
- started late or no specific treatment.

2. Chronic EBV infection formed not earlier than 6 months after acute infection, and in the absence of acute mononucleosis in history - after 6 months or more after infection.Often the latent form of infection with a decrease in immunity becomes chronic infection.Chronic EBV infection may occur in the form of chronic active EBV infection, hemophagocytic syndrome associated with EBV, atypical forms of EBV (recurrent bacterial, fungal and other infections of the digestive system, respiratory tract, skin and mucous membranes).

chronic active EBV infection is characterized by a prolonged course and frequent relapses.Patients concerned about weakness, fatigue, excessive sweating, prolonged mild fever to 37,2-37,5 °, skin rash, sometimes the articular syndrome, pain in the muscles of the trunk and limbs, heaviness in the right upper quadrant, the sense of discomfort in the throat, slight coughand congestion in the nose, some patients have neurological disorders - unexplainable headaches, memory impairment, sleep disorders, frequent mood swings, tendency to depression, patients are not careful, a decrease of intelligence.Often patients complain of an increase in one or lymph node groups may increase the internal organs (spleen and liver).
Along with such complaints when questioning the patient turns the presence of recent frequent catarrhal infections, fungal infections, joining other herpetic disease (eg, herpes simplex on the lips or genital herpes, etc.).
In support of clinical and laboratory data will be signs (changes in the blood, immune status, specific tests for antibodies).
In marked decrease in immunity in patients with chronic active EBV infection occurs generalization of the process and may result in internal organs with the development of meningitis, encephalitis, polyradiculoneuritis, myocarditis, glomerulonephritis, pneumonia and others.

Hemophagocytic syndrome associated with EBV manifested as anemia, pancytopenia, Go (a decrease of almost all blood components associated with the inhibition of hematopoiesis germs).Patients may experience fever (undulating or intermittent, with which it is possible both sharp and gradual rise in temperature with the restoration to normal values), swollen lymph nodes, liver and spleen, abnormal liver function, laboratory abnormalities in the blood in the form of a reduction of both red blood cells, soand white blood cells and other blood components.

Erased (atypical) forms EBVI : more often it is a fever of unknown origin persisting for months, years, accompanied with an increase in lymph nodes, sometimes articular manifestations, muscle pain;another option - it is a frequent secondary immunodeficiency viral, bacterial, fungal infections.

3. Congenital EBV infection occurs when there is an acute or chronic form EBVI active EBV infection, which arose during the mother's pregnancy.Characterized possible defeat of the internal organs of the child in the form of interstitial pneumonia, encephalitis, myocarditis and other.There are prematurity, preterm delivery.In the blood-born baby can circulate as the maternal antibodies to the Epstein-Barr virus (IgG to EBNA, VCA, EA antigens), and clear evidence of intrauterine infection - the child's own antibodies (IgM to EA, IgM to VCA antigens of the virus).

4. « chronic fatigue syndrome » is characterized by persistent fatigue that does not go after a long and good rest.For patients with chronic fatigue syndrome is characterized by muscle weakness, periods of apathy, depression, mood lability, irritability, sometimes a flash of anger, aggression.Patients languid, complain of impaired memory, reduced intelligence.Patients with poor sleep and disturbed sleep as a phase and observed fitful sleep, insomnia is possible and drowsiness during the day.At the same time characterized by autonomic disorders: tremor, or trembling fingers, sweating, occasionally a slight fever, poor appetite, pain in the joints.Under
workaholics risk, those with high physical and mental work, persons who are in the acute stress, and in the chronic stress.

5. HIV-associated diseases
«hairy leukoplakia» tongue and oral mucosa occurs in severe immunodeficiency
associated more frequently with HIV infection.On the side surfaces of tongue and in the mucosa of the cheeks, gums appear whitish folds that gradually merge, forming white plaques inhomogeneous surface, if coated grooves, cracks, erosive surface.Usually, no pain in this disease.

hairy leukoplakia language

Lymphoid interstitial pneumonia is polyetiological disease (there is a connection with Pneumocystis, as well as with EBV) and is characterized by shortness of breath, unproductive cough
on the background temperature and symptoms of intoxication, and progressive weight losspatients.Patient enlarged liver and spleen, lymph nodes, salivary gland enlargement.When X-ray bilateral lobar interstiialnye foci of lung tissue inflammation, roots extended unstructured.

6. Oncological lymphoproliferative disease (Burkitt's lymphoma, nasopharyngeal carcinoma - NFC, T-cell lymphoma, lymphoma and other nehodzhinskaya)

Diagnostics Epstein-Barr virus infection

1. preliminary diagnosis always exposed on the basis of clinicalepidemiological data.

infectious disease doctor Bykov NI