Causes and pathogenesis of cytomegalovirus infection

Cytomegalovirus infection in children is widespread, most people suffer a latent, latent or opportunistic form of the disease at an early age. In 70-80% of adults, viral neutralizing antibodies are found in the blood. In 4-5% of pregnant women, the virus is excreted in the urine, in scrapings from the cervix, it is determined in 10% of women, in milk - in 5-15% of nursing. Among newborns that died from various causes, cytomegalovirus cells in the salivary glands are found in 5-30% of cases, and signs of generalized infection reveal in 5-15%.

The source of cytomegalovirus infection is only a person, a sick person or a virus carrier. Transmission is carried out mainly by contact, less often by airborne droplets. In addition, infection can also occur parenterally with transfusion of blood or its products. Newborns can be infected through the mother's milk. The transplacental pathway of transmission of cytomegalovirus infection has been reliably proven. Infection of the fetus occurs from the mother - carrier of the virus. In these cases, cytomegalovirus can be detected in the placenta, although there are no clinical manifestations of the disease in the mother. Cytomegalovirus infection is transmitted directly through the damaged placenta or during the passage of the child through the mother's birth canal. However, not all intrauterine infections are born with manifest symptoms of the disease. More often in newborns, the infection is latent with giant cell metamorphosis in the salivary glands. With age, the frequency of detection of cells containing cytomegalovirus decreases with a simultaneous increase in the number of individuals with antibodies to cytomegalovirus in the blood. Humoral immune response is also produced with latent infection - complement-binding and virus-neutralizing antibodies appear in the serum.

[1], [2], [3], [4], [5], [6], [7], [8], [9]

Pathogenesis of cytomegalovirus infection

With intrauterine infection, cytomegalovirus easily penetrates the placenta and may be the cause of malnutrition, stillbirth, congenital malformations and malformations. When infected during passage of the birth canal or immediately after birth, the cytomegalovirus infection manifests itself in the postnatal period as a localized lesion of salivary glands or in generalized form, with damage to the brain and spinal cord, liver, spleen, lungs, kidneys and other organs. The epithelial resistance of the virus, especially to the epithelium of the glandular organs, is of great importance. In response to intracellular parasitization of the virus, a pronounced infiltrative-proliferative process arises with a violation of the function of the affected organ. In the pathogenesis of generalized forms, the general toxic effect of the virus, as well as the DIC syndrome and functional insufficiency of the adrenal cortex, can be important.

The nature of the developing pathological process (localized or generalized) depends solely on the degree of maturity of the fetus, concomitant diseases, immune reactivity, including residual anti-cytomegalovirus immunity in the mother and child.

In the genesis of chronic forms of infection, the ability of cytomegalovirus to persist and reproduce in leukocytes, mononuclear phagocyte system and lymphoid organs is of great importance. When immunodepression, the virus can leave the cells and affect many organs.