Contemporary features of infectious mononucleosis in children

Objective : to identify current clinical and laboratory characteristics of infectious mononucleosis in children. Materials and methods : this study presents an analysis of 50 clinical cases of infectious mononucleosis in children hospitalized at the Orenburg Regional Clinical Infectious Diseases Hospital in 2025. To confirm the diagnosis, blood and saliva were tested using polymerase chain reaction to detect Herpes virus DNA, nasopharyngeal swabs were tested using PCR for respiratory viruses and SARS-CoV-2, and oropharyngeal mucus was bacteriologically tested for opportunistic pathogens. Results : it was established that infectious mononucleosis was characterized by the development of typical syndromes (intoxication, lymphoproliferative, hepatosplenic). However, at the onset of the disease, intoxication syndrome and oropharyngeal changes predominated, often leading to misdiagnosis and lack of appropriate etiotropic treatment at the prehospital stage (100%) and late hospitalization of children (66%). Conclusions : the overwhelming majority (78%) of patients had liver damage with the development of cytolysis syndrome. More than half (56%) of children had mixed infections: viral-viral (26%) and viral-bacterial (30%), which aggravated the severity of infectious mononucleosis and required complex etiotropic therapy. A comparative analysis of the course of infectious mononucleosis in children with mono- and mixed infections revealed significant differences in the severity of cytolysis syndrome in children with mixed viral infections with long-term recovery of AST and ALT levels (14-28 days), which must be taken into account in the rehabilitation program for such patients.