We studied the risk factors, etiology, clinical features and the effectiveness of therapy of COVID-19-associated pulmonary aspergillosis (CAPA) in adult patients. In this retrospective study, we included 45 patients with proven (7%) and probable (93%) CAPA. The ECMM/ISHAM, 2020 criteria were used to diagnose CAPA. A case-control study was conducted to study the risk factors of CAPA; the control group included 90 adult COVID-19 patients without IA. In CAPA patients, the main underlying diseases were diabetes mellitus (33%), and hematological and oncological diseases (31%). The probability of CAPA developing significantly increased with lymphocytopenia >10 days (OR = 8.156 (3.056–21.771), p = 0.001), decompensated diabetes mellitus (29% vs. 7%, (OR = 5.688 (1.991–16.246), p = 0.001)), use of glucocorticosteroids (GCS) in prednisolone-equivalent dose > 60 mg/day (OR = 4.493 (1.896–10.647), p = 0.001) and monoclonal antibodies to IL-1ß and IL-6 (OR = 2.880 (1.272–6.518), p = 0.01). The main area of localization of CAPA was the lungs (100%). The clinical features of CAPA were fever (98% vs. 85%, p = 0.007), cough (89% vs. 72%, p = 0.002) and hemoptysis (36% vs. 3%, p = 0.0001). Overall, 71% of patients were in intensive care units (ICU) (median—15.5 (5–60) days), mechanical ventilation was used in 52% of cases, and acute respiratory distress syndrome (ARDS) occurred at a rate of 31%. The lung CT scan features of CAPA were bilateral (93%) lung tissue consolidation (89% vs. 59%, p = 0.004) and destruction (47% vs. 1%, p = 0.00001), and hydrothorax (26% vs. 11%, p = 0.03). The main pathogens were A. fumigatus (44%) and A. niger (31%). The overall survival rate after 12 weeks was 47.2%.

We studied the risk factors, etiology, clinical manifestations, and treatment outcomes of COVID-19-associated invasive candidiasis (COVID-IC) in adult patients admitted to six medical facilities in St. Petersburg. (November 2020–December 2022). In this retrospective study, we included 72 patients with COVID-IC with a median age of 61 years (range 29–96), 51% of whom were women. The predisposing factors for COVID-IC were a central venous catheter (CVC) for more than 10 days (the odds ratio (OR) = 70 [15–309]), abdominal surgical treatment performed in the previous 2 weeks (OR = 8.8 [1.9–40.3]), bacteremia (OR = 10.6 [4.8–23.3]), pulmonary ventilation (OR = 12.9 [5.9–28.4]), and hemodialysis (OR = 11.5 [2.5–50.8]). The signs and symptoms of COVID-IC were non-specific: fever (59%), renal failure (33%), liver failure (23%), and cardiovascular failure (10%). Candida albicans (41%) predominated among the pathogens of the candidemia. The multidrug-resistant Candida species C. auris (23%) and C. glabrata (5%) were also identified. Empirical therapy was used in 21% of COVID-IC patients: azole-93%, echinocandin–7%. The majority of COVID-IC patients (79%) received, after laboratory confirmation of the diagnosis of IC, fluconazole (47%), voriconazole (25%), echinocandin (26%), and amphotericin B (2)%. The 30 days overall survival rate was 45%. The prognosis worsened concomitant bacteremia, hemodialysis, and long-term therapy by systemic glucocorticosteroids (SGCs), bronchial colonization with Candida spp. The survival prognosis was improved by the early change/replacement of CVC (within 24 h), the initiation of empirical therapy, and the use of echinocandin. Conclusions: We highlighted the risk factors that predispose COVID-19 patients to candidiasis and worsen the survival prognosis. Their individual effects in patients with COVID-19 must be well understood to prevent the development of opportunistic co-infections that drastically lower chances of survival.

Invasive fungal infections (IFIs) are a serious threat to patients with hematological diseases. These infections are characterized by high mortality and lead to significant financial costs for treatment. The most common pathogens of IFIs are Aspergillus spp. and Candida spp., but in recent years, cases of infections caused by rare pathogens have become more frequent. Diagnosis of IFIs and choice of treatment remain challenging due to the nonspecificity of symptoms and the diversity of clinical cases. In this regard, the problem of start time and choice of antifungal therapy remains of current interest. This review briefly describes diagnostic criteria, challenges associated with IFIs diagnosing, provides evidence for empiric and preventive strategies as two early treatment approaches, and examines the impact of therapy initiation on patient outcomes. Treatment of IFIs in hematologic patients should be individualized. At the same time, early administration of therapy with broad-spectrum drugs for febrile neutropenia and parallel diagnostic measures can improve treatment outcomes. There is a lack of current data on the benefits of specific treatment strategies, highlighting the need for further research.

Introduction. Systemic immune-inflammatory diseases can affect many systems and organs and have an extremely severe course with complications, causing multiple organ failure and death. Often, children with such diseases require hospitalization in the intensive care unit (ICU). For example, approximately 50% of patients with multisystem inflammatory syndrome, associated with COVID-19 in children (MIS-C) and systemic lupus erythematosus require hospitalization in the ICU.The objective was to determine risk factors for lethal outcome in children with immune-inflammatory diseases hospitalized in the ICU.Materials and methods. The retrospective cohort study included 51 patients (23 boys, 28 girls) with immune-inflammatory diseases such as MIS-C (n = 18), systemic rheumatic diseases (n = 24), and sepsis (n = 9) aged 7 months to 17 years, hospitalized in the ICU of the Clinical Hospital of St. Petersburg State Pediatric Medical University in the period from 2007 to 2023.Results. 13 patients (25.5%) died 39 (17; 62) days after admission to the ICU. Patients with a lethal outcome were significantly older and were admitted to the ICU later than surviving patients (30 vs. 7 days, p = 0.013), and also spent a longer time in the ICU (30 vs. 6 days, p = 0.003). Lethal outcome was more common in older children (> 162 months) who were admitted to the ICU later (> 26 days from the disease onset/diagnosis), who received previous immunosuppressive therapy, developed invasive mycosis during their stay in the ICU and were in the ICU for a long time (> 15 days). Multiple regression analysis revealed three significant predictors of lethal outcome: age > 162 months, time of admission to the ICU > 26 days from diagnosis, and ICU stay > 15 days (r2 = 0.458, p < 0.00001).Conclusion. Early identification of patients at high risk of adverse outcome is a primary goal for optimization of therapy. Careful monitoring of immunosuppressive therapy and prevention of invasive mycosis can improve the outcome in children with systemic immune-mediated diseases.

   Objective.  To characterize the epidemiological and microbiological features of fungal colonization and infections in neonates.    Materials and methods. An observational epidemiological study was conducted. It comprised a retrospective, single-center analysis of microbiological surveillance data from 2001 to 2025, a prospective, single-center study of fungal colonization and infections from 2021 to 2025, and a multicenter analysis of clinically significant fungal infections in neonates across three hospitals in Saint Petersburg.    Results.  During 2021–2025, 376 cases of fungal infections in neonates were identified in three hospitals. Outbreak-associated cases predominated and accounted for 82.2 % of all infections. Вloodstream infections and catheter-associated bloodstream infections accounted for 85 %. The leading pathogen was Candida parapsilosis, responsible for 40 % of infections. Compared with C. albicans, C. parapsilosis was more frequently associated with invasive infections, bloodstream infections, and catheter-associated bloodstream infections. Positive correlation between the rate of episodes detected on admission and hospital-acquired episodes was revealed, with C. albicans predominating in both groups (r = 0.76). In the prospective, single-center study, colonization accounted for 89.0 % of cases, while 60.3 % were hospital-acquired. Malassezia furfur was detected in 6.1 % of cases and was associated with late hospital-acquired detection.    Conclusions.  Fungal colonization and infections in neonates demonstrate species-specific epidemiological patterns. Hospital spread of C. albicans was mainly associated with strains introduced by colonized patients on admission. In contrast, C. parapsilosis showed hospital transmission and accounted for a substantial proportion of invasive infections and outbreak-associated cases. Detection of M. furfur and other rare yeasts highlights the need for expanded etiological diagnostics in high-risk neonatal units.

Objectives. Actinomycosis in children has not been studied enough, the number of publications is limited. Actinomycosis of the knee joint is very rare, the disease mimics tuberculosis or malignant neoplasms, which can lead to late diagnosis and inadequate treatment. Materials and methods. We report on the first case of an 8-year-girl with actinomycosis knee. Diagnosis is based on histological examination. Results. Surgical resection of infected tissue and longterm antibiotic therapy for 4.5 months was effective in the treatment of pediatric patient with knee actinomycosis. In the scientific literature no such clinical case was found. С onclusion. Case of successful treatment of pediatric patient with knee actinomycosis is presented for the first time.