Vol 28, No 3 (2023)

BACKGROUND: The contribution of random and regular factors in the process of epidemic hemorrhagic fever is unknown, which necessitates the search for the reasons for the formation of severe and fatal cases.

AIM: Based on the incidence of epidemic hemorrhagic fever in Primorsky Krai over a long period, we aimed to establish the role of the main determinants of the epidemic process and to demonstrate the causality of local manifestations in epidemic foci in patients with epidemic hemorrhagic fever.

MATERIALS AND METHODS: In this comprehensive descriptive epidemiological and clinical study, we undertook the epidemiological analysis of the incidence of epidemic hemorrhagic fever and data from examinations of the foci of infection. We performed a clinical observation (case study) of a case of epidemic hemorrhagic fever with a fatal outcome at the Regional Clinical Infectious Diseases Hospital in March 2022. The object of the study is statistical data on officially registered cases of epidemic hemorrhagic fever in Primorsky Krai from 1995 to 2021.

RESULTS: The proportion of random factors in the epidemic process of epidemic hemorrhagic fever in the period under review was 28.7% of the incidence, which formed deviations from the typical curve, but did not participate in the formation of cyclicity in the long-term dynamics. Variable factors that formed cyclicity and random deviations together determined 53.4% of the incidence. They were fully related to seasonal morbidity (67.8%). Moreover, the remaining 14.4% of seasonality was formed by constant factors for each month. Factors constant for all months of the year form a year-round form, that is, 32.2% of the incidence.

In the clinical and epidemiological observation of a lethal case of epidemic hemorrhagic fever, infection was noted under conditions of dust formation, such as when restoring order in a closed room at a negative temperature (sweeping) and high titers of specific antibodies resulting from repeated encounters with the pathogen in residential and occupational types of morbidity and the accompanying illnesses.

CONCLUSIONS: The study of the incidence of epidemic hemorrhagic fever demonstrated a high resolution of epidemiological analysis by using a binary method in zoonoses. The patterns and features of human morbidity were controlled by natural and social factors more strictly than by biological ones. The determinants of the socio-ecological system in epidemic hemorrhagic fever in Primorsky Krai make it possible to specify the tactics and strategy for the implementation of epidemiological surveillance.

BACKGROUND: Microsporia is a widespread type of dermatomycosis, especially among the children's population, representing a medical and social problem, because of the duration and high cost of treatment and the moral and material damage incurred to the patients and their family members. The absence of regulatory documents (except for clinical recommendations) regarding the epidemiology of this nosology, the organization and control of mandatory anti-epidemic measures, and the timing of their execution determine the relevance of infection.

AIM: To present the epidemiological characteristics of the incidence of microsporia in the population of the Republic of Tatarstan with clinical and epidemiological analyses of the outpatient records of patients in the Nizhnekamsk region.

MATERIALS AND METHODS: A retrospective analysis of the incidence of microsporia in the study population was conducted with reference to the official statistical forms for 2011–2021. The analysis of the outpatient charts and medical histories of the residents of Nizhnekamsk district who were diagnosed with microsporia and consulted a dermatovenerologist in 2020–2022 and were then hospitalized in a skin and venereological dispensary was selectively carried out from the Journal of Infectious Diseases (format no. 060/y). The data were processed in Microsoft Excel (USA) and Startech (Russia).

RESULTS: During 2011–2021, a statistically significant trend of a decrease in the incidence of microsporia in the Russian Federation was noted along with a corresponding increase in the Volga Federal District and the Republic of Tatarstan, with the residents of Tatarstan accounting for 66% of newly detected cases of microsporia in Russia and 59% in the Volga Federal District. High rates of microsporia incidence in the republic were registered among the city residents (81.3%). During the period of analyses in Tatarstan, among the reported cases, children aged 0–14 years (77%) with microsporia accounted for 77% of all cases, which included 53.7% girls. Among adults, persons aged 18–29 years accounted for 9% of all cases, of which 73.2% were women.

When analyzing the outpatient records of patients-residents in the Nizhnekamsk district of the Republic of Tatarstan (n=1010), the main subgroup with microsporia was identified as children aged 7–14 years (n=519 [51.4%]). Every year, 53.9% of schoolchildren and 28.6% of preschool children get dermatophytes. The source of microsporia infection was stray and domestic cats for 298 (29.5%) cases. The major proportion of patients with microsporia, that is, 83.9% (n=847), showed localization of the process on smooth skin. In children, microspore was represented by smooth skin lesions in 744 (80.9%) cases and by scalp in 175 (19.1%). In adults, 83 (91.2%) cases of smooth skin lesions and 8 (8.8%) cases of scalp cases were registered.

CONCLUSIONS: Microsporia remains relevant owing to its high prevalence, especially among children, which dictates the need for anti-epidemic, therapeutic, and preventive measures aimed at timely detection and isolation of patients infected with this mycosis, as well as trapping, isolation, treatment, and vaccination of homeless domestic animals, who are the main sources of the disease. The continued growth of morbidity rates in Tatarstan is an indicator of the instability of the epidemiological situation, indicating the need to improve the measure toward preventing their spread in cooperation with the veterinary service.

Sepsis is a life-threatening organ dysfunction caused by a disturbed response to infection. Its development is preceded by systemic inflammatory response syndrome, which is the overall inflammatory response of the body to severe lesions. The role of opportunistic pathogens in the development of systemic inflammatory response syndrome and sepsis may be known, but the value of the intestinal microbiome remains underestimated in this context.

Experimental models are widely employed to study the role of the microbiome in the development of sepsis. Animal models of sepsis are created by disrupting the barrier function of the host intestine through cecal ligation/puncture, installation of an ascending bowel stent, and intraperitoneal feces injection. Toxemia is reproduced by the injection of lipopolysaccharides, peptidoglycans, lipoteichoic acid, CpG DNA, zymosan, and synthetic lipopeptides.

The review systematized data on the role of the cell wall or membrane components of gram-positive and gram-negative bacteria, which are representatives of the intestinal microbiome in the pathogenesis of systemic inflammatory response syndrome and sepsis.