RESUMEN
Objective. Detection of additional factors favoring progression of COVID-19 and developing lethal outcomes in hospitalized patients. Materials and methods. Analysis of 98 medical records of lethal cases of patients that underwent hospitalization with diagnosis of COVID-19 associated pneumonia of two in-patient facilities of the Amur oblast and Khabarovsk krai was performed. Two groups were formed: first included medical records of patients hospitalized in severe condition (n = 52) and second group included patients with state of moderate severity (n = 46). Length of hospitalization stay, time from admission to the medical facility to progression of the disease, time from hospitalization to death and bacterial pathogens species composition isolated from lungs tissue autopsy material were analyzed. Statistical assessment of obtained data was performed with StatSoft Statistica 12.0. Results. Majority of patients of 1st and 2nd groups (66.7 ± 6.80% and 69.6 ± 6.78%) were hospitalized on fourth day of the COVID-19 clinical manifestations onset or later. Two thirds of patients hospitalized in severe condition progressed to critical health status on 1st–3rd day of hospitalization. Majority of second group patients (65.2 ± 7.02%) deteriorated from moderate severity to severe health condition on 4th–14th day of hospital stay. Bacteriological assessment analysis of autopsy material revealed that material obtained from first group showed more frequent absence of bacterial flora growth compared with second group both in the Amur oblast (44.4 ± 9.74% и 29.4 ± 11.39%) and in the Khabarovsk krai (в 40.0 ± 10.0% and 27.6 ± 8.45% of cases). Klebsiella pneumoniae (57.7 ± 5.86%) and Candida spp. (18.3 ± 4.59%) were revealed more frequently in the structure of diagnosed pathogens. Substantial proportion of pathogens (81.7 ± 4.59%) were isolated in autopsy material of patients which hospital stay was 4 days and longer. Prolonged hospital stay was associated with more frequent detection of K. pneumoniae and Candida spp. in patients that suffered from COVID-19 pneumonia and eventually died from the disease. With duration of hospitalization of 4 days and longer Acinetobacter baumannii – an extremely virulent pathogen with natural drug resistance was isolated from autopsy material. Conclusion. Factors influencing unfavorable outcomes of COVID-19 include signs of secondary bacterial infection as well as detection of aggressive drug-resistant bacterial microflora that most likely had nosocomial origin due to prolonged hospitalization. © 2021, Dynasty Publishing House. All rights reserved.