What is Infectious Mononucleosis in Children?
Infectious mononucleosis is a multi-cause disease caused by viruses of the Herpesviridae family. The course is accompanied by tonsillitis, fever, enlargement of the liver and spleen, polyadeptitis. Aptipic mononuclear cells appear in the peripheral blood.
According to the international classification, there are such types of infectious mononucleosis:
- cytomegalovirus mnononucleosis;
- mononucleosis caused by gamma herpes virus (Epstein-Barr virus);
- infectious mononucleosis of another etiology;
- unspecified infectious mononucleosis.
In 50% of cases, the disease is caused by Epstein-Barr virus, in 25% by cytomegapovirus, in the remaining cases by type IV herpes virus. Manifestations of the disease are weakly dependent on the etiology.
The source of infection is patients in whom the disease manifests itself in a manifest or asymptomatic form, as well as virus isolators. 70-90% of survivors of infectious mononucleosis periodically secrete viruses with oropharyngeal secretion.
The virus is in the nasopharynx for 2 to 16 months after the disease. It can be detected using swabs. The virus is transmitted primarily by airborne droplets. The infection is easily transmitted through the saliva of a sick person, because infectious mononucleosis is often called the “kissing disease”. Children can become infected through toys if they have infected saliva. Also, the infection is transmitted with donated blood, if the virus was not detected in it, and sexually. It is unlikely, but transmission through water and food is not excluded. The virus also passes from mother to fetus.
The infection is transmitted quickly and widely due to crowding, the use of common dishes, bedding. Passing objects from mouth to mouth can also be infected. The infection quickly settles in the body when the general and sixth immunity is reduced.
The disease is cyclical, the duration of each epidemic wave is from 6 to 7 years. Bursts are observed in spring, a slight increase in the incidence rate falls in October. The epidemic process progresses mainly due to erased and asymptomatic forms of the disease. The infection affects mainly men and boys. The highest incidence rate is observed among preschool children in kindergartens and nurseries.
Most often, the disease is expressed by unrelated cases, but epidemics, as mentioned above, occur. Erased and asymptomatic forms affect up to 40-45% of those infected.
The division of infectious mononucleosis is carried out according to severity, type and course. Typical mononucleosis is accompanied by major symptoms, such as swollen lymph nodes, spleen, liver, atypical mononuclear cells, tonsillitis.
Atypical forms combine erased, asymptomatic and visceral forms of the disease. By severity, typical forms are classified into mild, moderate and severe. Severity is determined by the severity of intoxication, an increase in lymph nodes, the nature of damage to the oropharynx and nasopharynx, and an increase in the spleen and liver. The number of atypical mononuclear cells in peripheral blood is also taken into account. Atypical forms are always referred to as lungs, and visceral forms to heavy. The course of infectious mononucleosis can be smooth, uncomplicated, complicated and protracted.
Causes of Infectious Mononucleosis in Children
The causative agent of the disease is Epstein-Barr virus, containing DNA. It belongs to the genus Lymphocryptovirus. The virus has the ability to replicate, including in B-lymphocytes. It activates cell proliferation, not cell death, unlike other viruses. This virus quickly dies in the environment, especially when it dries. Epstein-Barr virus can cause not only infectious mononucleosis. It also causes Burkitt’s lymphoma and nasopharyngeal carcinoma.