EPIDEMIOLOGIC FEATURES OF CLUSTERED MORBIDITY CAUSED BY ENTEROVIRAL INFECTIONS IN THE URAL FEDERAL DISTRICT AND WESTERN SIBERIA IN 2017

Abstract

Aim. Delineation of epidemiologic features of clustered morbidity caused by enteroviral infections (EVI) in the Ural Federal District (UFD) and West Siberia in 2017. Materials and methods. Retrospective epidemiologic analysis of clustered EVI morbidity was performed with the data obtained from the standardized Federal statistical observation reports and the data provided by the regional Departments of the Federal Service for Supervision of Consumer Rights Protection and Human Well-Being (Rospotrebnadzor). Detection and identification of enteroviruses was carried out by molecular genetic methods. Results. Totally 51 focus of clustered EVI was registered. The incidence density and time course of outbreaks closely correlated with the general EVI incidence level (r = 0.65; p < 0.05) and seasonal variations (r = 0.80; p < 0.05) at the given territory. Droplet nuclei transmission was considered the main route of infection in 68.2% of cases, in 22.0% - as an accessory route, and in 14.6% - as an obligate route. Contact transmission via fomites was reported as an obligate route in 9.8% of outbreaks. In the etiological structure, the proportion of Enterovirus A species was 51.4% (Coxsackievirus A6 (CV-A6) - 43.2%), Enterovirus B species - 70.3% (Echovirus 30 (E30) - 48.6%). Conclusion. In 2017 the clustered morbidity caused by EVI in the UFD and Western Siberia involved mainly children under 6 years of age from preschool institutions, where outbreaks of low incidence density with short duration were observed. Two genotypes of enteroviruses (E30 and CV-A6) were prevalent in the etiological structure of the outbreaks, therefore determining predominant clinical forms of EVI: aseptic meningitis or hand, foot, and mouth disease.