Vol 28, No 2 (2023)

BACKGROUND: This study was conducted to determine the characteristics of various viral respiratory pathogens spreading during the epidemic season 2021–2022 and the frequency of co-infection with SARS-CoV-2 and influenza.

AIM: To assess the development of the influenza epidemic and frequency of cases of co-infection with respiratory pathogens in patients with acute respiratory viral infections between 2021 and 2022.

MATERIALS AND METHODS: Traditional and hospital epidemiological surveillance methods for acute respiratory viral infections were used.

RESULTS: The epidemic season of 2021–2022 was characterized by the early activity of the influenza A(H3N2) virus and the emergence and rapid spread of the omicron variant of SARS-CoV-2. The distribution of different respiratory pathogens during the epidemic season 2021–2022 was clearly traced: SARS-CoV-2 (18.8%) was predominant, followed by influenza viruses (10.6%) and pathogens of other acute respiratory viral infections (0.4–3.7%). With respect to influenza A (H3N2) and B viruses, the heterogeneity of their populations and drift variability in relation to vaccine strains were noted.

DISCUSSION: The frequency of co-infection with various respiratory pathogens was low, i.e., it was no more than 0.1%according to traditional surveillance, and no more than 9.2% in the hospital surveillance. The rationale for updating the composition of influenza vaccines for the countries in the Northern Hemisphere for 2022–2023 season was identified.

CONCLUSION: At present, early diagnosis of influenza is important given the availability of effective drugs with a direct mechanism of action for the prevention and treatment of this pathogen. Timely use of anti-influenza drugs will reduce the risks of a severe course, complications, and death, including co-infection with SARS-CoV-2.

According to the World Health Organization Global Tuberculosis Report, published in 2022, tuberculosis and its drug-resistant forms are on the rise for the first time in recent years. The ability to become immune to anti-tuberculosis drugs is a fundamental feature of the tuberculosis agent. In some cases, tuberculosis develops a transient resistance to antibacterial drugs based on a combination of adaptive biological properties of the mycobacterium without altering the genetic apparatus. This phenomenon is called drug-induced tolerance. Its development is associated with the slowing or altering of bacterial metabolism, increasing the thickness of the cell wall, activation of specific molecular pumps, and removal of medicinal substances from outside the cell. The same and some other mechanisms are involved in the development of another phenomenon — drug resistance, which is associated with inherited changes in the genetic apparatus of mycobacterium. The review is devoted to the molecular bases of the interaction of mycobacterium tuberculosis with anti-tuberculosis drugs and its epidemiological significance.

Annually, data are accumulating on the involvement of opportunistic microorganisms in the development of inflammatory diseases in humans, maintaining a chronic inflammatory response and, thus, adapting to the conditions of existence in the biotopes of the human body. This review provides information on the interactions of microorganisms of medical importance, which affects the virulence of both opportunistic pathogens and “classical” pathogens, which probably underlie the chronicity of infection and inflammation. Often, opportunistic pathogenic species cannot fully realize their pathogenic potential, which is observed in numerous cases under conditions of microbial symbiosis. Thus, a revision of approaches to interpreting the results of microbiological methods is necessary, which takes into account the functional activity of the total microflora and the search for individual extrachromosomal genetic elements as a marker of the pathogenicity of microorganisms.

Brucellosis is one of the most common zoonotic diseases worldwide. The epidemiological situation of brucellosis in the Russian Federation is characterized as unfavorable. Brucellosis remains a problem in regions with developed animal husbandry. The variety of clinical manifestations and the absence of specific symptoms of brucellosis make its diagnosis challenging. The clinical case presented in this paper illustrates the delayed diagnosis of brucellosis in a 10-year-old patient presenting with fever and enlarged lymph nodes, liver, and spleen. The failure in the provision of medical care was attributed to the lack of the alertness of doctors regarding brucellosis, insufficient interpretation of epidemiological history data, and incorrect assessment of the totality of the clinical syndrome of the disease and laboratory parameters. As a result, brucellosis was diagnosed only 6 months after disease onset. Subsequent etiotropic therapy led to the stabilization of the patient’s condition, who was discharged from the hospital with recommendations under the supervision of an infectious disease specialist.