Enterovirus infection morbidity and peculiarities of nonpolio enteroviruses circulation on some territories of Russia in 2017

Aim: Characteristics of enterovirus infection morbidity and study of peculiarities of enterovirus circulation on some territories of Russia in 2017. Materials and methods: We investigated more than 5000 samples from the patients with enterovirus infection. The isolation and identification of enteroviruses were conducted by virological method and by partial sequencing of the genome region VP1. Phylogenic trees were constructed according to the method of Bayesian Monte Carlo Markov Chain. Results: Epidemic process and clinical picture of enterovirus infection were not the same on different territories. Peculiarities of the circulation of different types of enteroviruses on the territories were also different. In Saratov region 65% of cases were represented by enterovirus meningitis. In Murmansk region and in the Komi Republic enterovirus infection with exanthema prevailed, 95% and 60% correspondingly. In Saratov region enterovirus ECHO18 was the etiological agent of enterovirus meningitis. In Murmansk region and in the Komi Republic the cases were connected mainly with Coxsackieviruses A6. The strains of enterovirus ECHO18 were distributed to three clusters. The strains which provoked enterovirus meningitis in Saratov region belonged to cluster 3, they were formed separately from other strains of this enterovirus type and differed from the stains of ECHO18 which circulated in the North-West of Russia. The strains of Coxsackieviruses A6 identified in the North-West of Russia belonged to three sub-genotypes 5, 6, 8 of pandemic genotype of CoxsackievirusesA6. The majority of the strains belonged to sub-genotypes 6 and 8 which in 2017 dominated in the structure of Coxsackieviruses A6 in the North-West of Russia and in Russia. Conclusion: Epidemic peaks of enterovirus infection represented by different clinical forms of the disease were provoked by different types of enteroviruses. Enterovirus ECHO18 was the etiological agent of enterovirus meningitis. The main etiological factors of enterovirus infection with exanthema were Coxsackieviruses A6 of different sub-genotypes.