We evaluated associations between serum 25-hydroxyvitamin D [25(OH)D] level and severity of new coronavirus infection (COVID-19) in hospitalized patients. We assessed serum 25(OH)D level in 133 patients aged 21–93 years. Twenty-five (19%) patients had severe disease, 108 patients (81%) had moderate disease, and 18 (14%) patients died. 25(OH)D level ranged from 3.0 to 97.0 ng/mL (median, 13.5 [25%; 75%, 9.6; 23.3] ng/mL). Vitamin D deficiency was diagnosed in 90 patients, including 37 with severe deficiency. In patients with severe course of disease, 25(OH)D level was lower (median, 9.7 [25%; 75%, 6.0; 14.9] ng/mL), and vitamin D deficiency was more common than in patients with moderate course (median, 14.6 [25%; 75%, 10.6; 24.4] ng/mL, p = 0.003). In patients who died, 25(OH)D was 9.6 [25%; 75%, 6.0; 11.5] ng/mL, compared with 14.8 [25%; 75%, 10.1; 24.3] ng/mL in discharged patients (p = 0.001). Severe vitamin D deficiency was associated with increased risk of COVID-19 severity and fatal outcome. The threshold for 25(OH)D level associated with increased risk of severe course was 11.7 ng/mL. Approximately the same 25(OH)D level, 10.9 ng/mL, was associated with increased risk of mortality. Thus, most COVID-19 patients have vitamin D deficiency; severe vitamin D deficiency is associated with increased risk of COVID-19 severity and fatal outcome.

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.

Background. Hypokalemia is a common electrolyte complication among hospitalized patients with pneumonia caused by a new coronavirus SARS-CoV-2. Hyperactivation of the renin-angiotensin-aldosterone system (RAAS) is suggested as a possible cause of hypokalemia in patients with COVID-19.Objective. To investigate the RAAS activity in COVID-19 patients with and without hypokalemia and its possible association with treatment outcomes.Design and methods. The cross-sectional cohort study included 172 patients with COVID-19 pneumonia. Potassium, aldosterone and venous renin were measured in 77 patients. The differences in the levels of acute phase proteins, the degree of lung damage and the severity of COVID-19 were compared between patients with and without hypokalemia.Results. Hypokalemia was found in 19 of 77 patients (25%): the median potassium level in hypokalemia and eukalemia group was 3,1 [2,8–3,3] and 4,1 [3,9–4,5] mmol/L, respectively (p = 0,001). Plasma aldosterone and renin levels in patients with and without hypokalemia did not differ significantly: aldosterone 76,0 [57,7–121,5] and 70,9 [26,3–113,8] pg/ml (p = 0,23), renin 17,0 [8,5–47,2] and 11,0 [6,5–38,1] pg/ml (p = 0,35), respectively. Differences in the degree of lung tissue damage, acute phase proteins, severity of COVID-19, length of hospitalization and mortality in patients with and without identified electrolyte disturbances were also not significant.Conclusions. Our results showed that there were no laboratory signs of RAAS hyperactivation in COVID-19 patients with registered hypokalemia. Identification of the cause and clinical significance of hypokalemia among patients with COVID-19 needs to be specified.

Aim. To create algorithm and risk calculator for predicting the lethal outcome in patients with COVID-19.Materials and methods. Based on machine learning approach mortality risk calculator was developed in Almazov National Medical Research Centre using data of the hospitalised patients with an established diagnosis of COVID-19 (n=4071).Results. This mathematical model, which includes 11 significant features, has been proposed for estimation of fatal outcomes in the Clinical Infectious Hospital named after S.P. Botkin. Some key features were not assessed in most hospitals according to accepted standards of care for COVID-19. So systematic analysis of factors affecting the course of disease in patients (n=2876) were conducted and «urea» and «total protein» were replaced with «sex» and «BMI». Modified algorithm demonstrated high sensitivity and specificity. Conclusion. This calculator is able to predict hospitalisation outcome with high accuracy in patients infected with different strains of SARS-CoV-2. This decision support system may be used for risk stratification and following correct patients routing.