Circulation of non-polio enteroviruses in the Ural Federal District and Western Siberia in 2023: the return of an old foe?

Abstract

Human non-polio enteroviruses (NPEVs) cause a wide range of illnesses such as hand, foot, and mouth disease (HFMD), herpangina, and aseptic meningitis. In this study, we investigated the incidence of NPEV infections in the Ural Federal District and Western Siberia, Russia, from 2019 to 2023 in patients with various NPEV-associated diseases, identified the main circulating genotypes in 2023, and analyzed their epidemiological characteristics. A total of 384 samples that tested positive by polymerase chain reaction (PCR) for NPEVs were genotyped by semi-nested PCR specific for the VP1 gene. A total of 20 genotypes were identified among the patients in this study, with enterovirus A accounting for 57.2% of all typed samples, enterovirus B accounting for 41%, and enterovirus C accounting for 1.8%. Coxsackievirus A6 (CVA6) was the most common genotype in HFMD cases. Echovirus 30 (E30) was predominant in aseptic meningitis patients, and coxsackievirus A2 was primarily associated with herpangina. Phylogenetic analysis showed that most of the CVA6 strains identified in this study displayed a close genetic relationship to strains that circulated in China, while E30 genotypes circulating in the studied region belonged to subgenotype V. Laboratory-based monitoring and epidemiological surveillance for genetic changes and evolutionary studies are necessary for improving prevention and clinical care.