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Introduction. Enteroviruses (EV) are characterized by: species and type diversity, polymorphism of clinical manifestations, a tendency to epidemic spread, and are often the cause of disease outbreaks, which determines the relevance of monitoring EV strains in various clinical forms of infection, including in conditions of anti-epidemic measures. The aim of the study: to characterize the prevalence and diversity of non-polio enteroviruses (NPEV) types in children with acute intestinal infection (AII) in the period 2018–2023, including the COVID-19 pandemic. Materials and methods. The RT-PCR method was used to study 7302 samples of feces from children hospitalized with a diagnosis of AII in the infectious diseases hospital of Nizhny Novgorod. Genotyping of EV strains was carried out using fragment Sanger sequencing of the genome region encoding capsid protein 1 (VP1) and the online resource BLAST. Results. EVs were found in 5.0 ± 0.3% (1.7–7.8%), both in mono- and mixed infections with other enteric viruses. The long-term dynamics of the frequency of EV detection and the incidence of EV infection in children in the Nizhny Novgorod region was characterized by a sharp decrease in indicators in 2020 against the backdrop of the introduction of anti-epidemic measures. When genotyping 299 strains, 41 types of NPEV of 4 species were identified. The spectrum included the main pathogens of exanthema and neuroinfections and rare types found in “minor” or intestinal forms of infection. During the study period, a redistribution of NPEV species was established. Before the pandemic, the ratio of Enterovirus A : Enterovirus B : Enterovirus C species was as follows — 41.0 : 46.7 : 12.3%; during the 2020 pandemic season the ratio was 0.0 : 37.5 : 62.5%; after the lifting of restrictive measures — 47 : 29 : 23%, which may be due to the different effectiveness of the restrictive measures on the mechanisms of transmission of EVs of different types. Conclusion. The genetic diversity of NPEVs detected in children with AII complements information on the typical composition of the territorial enterovirus population. In children with AII, when the airborne transmission of SARS-CoV-2 was blocked, there was a decrease in the frequency of detection of viruses of the Enterovirus B type, the absence of detection of Enterovirus A and the constant presence of Enterovirus C.

According to current data, SARS-CoV-2 virus has the ability to cause multi-organ pathology, leading to acute damage of various organs and systems and long-term consequences characterized by polymorphic symptoms. Recently, a high incidence of invasive mycoses, particularly mucormycosis COVID-M, has been noted among the COVID-19 complications. The predisposing factor for the development of this pathology is diabetes mellitus, immunodeficiency states, and prolonged use of high doses of glucocorticosteroids. Mucormycosis is characterized by severe clinical manifestations and high lethality, and timely diagnostics of this pathology often represents a difficult problem. The aim of this study was to analyze a clinical case of rhino-orbital mucormycosis in convalescent COVID-19 patient. In the study, there was used mucopurulent nasal discharge from the patient previously hospitalized with a severe novel coronavirus infection. Here, we describe the methodology allowing to isolate and identify a pure mold fungus culture from the biomaterial using methods of routine bacteriology and MALDI-ToF mass spectrometry. Direct microscopy examination of nasal cavity discharge revealed branched non-septic hyphae with a characteristic branching angle, allowing to preliminarily diagnose invasive mucormycosis. Growth of mycelial fungus colony was observed by using Sabourauds medium with potassium tellurite. Microscopy of the pure culture revealed branching mycelium without septa, broad, with irregular thickness, unsegregated hyphae, and sporangia with a typical column specific to mucormycetes. Analysis of the obtained mass spectra allowed to establish the microbial species identity as Lichtheimia corymbifera. The latter along with other members of the order Mucorales, are known to cause mucormycosis. As a result of antifungal treatment (Amphotericin B) and timely surgical intervention, the patient was discharged from the hospital with prominent clinical improvement and no complaints during further outpatient follow-up period. The analysis of this clinical case showed the lack of alertness in some clinical diagnostic laboratories to detect pathogens of invasive mycoses. To avoid errors, while making a diagnosis, attention should be paid not only to detection of fungal spores in clinical material, but also take into account the structure of mycelium underlying major difference between yeast-like fungi, higher and lower molds. The isolation and identification of a pure pathogen culture allows to confidently verify the diagnosis, timely correct the treatment tactics and monitor circulation of mycotic agents to prevent occurrence of mycoses in most vulnerable patients cohorts.