[Risk of introduction and spread of polioviruses in closed-type child-care facilities].

AIM: Compare frequency of isolation of polioviruses in children living in closed-type facilities (orphanages) before and after the change in poliomyelitis vaccination scheme. MATERIALS AND METHODS: Feces samples of 207 children from 5 orphanages during immunization with oral poliomyelitis vaccine (OPV) and of 259 children from 4 orphanages during vaccination with inactivated poliomyelitis vaccine (IPV) were studied. Isolation and identification of polioviruses was carried out according to WHO recommendations. RESULTS: In orphanages, where children were immunized with the oral vaccines, 21 polioviruses were isolated. In orphanages, where only inactivated vaccine was used, 10 polioviruses were isolated, the presence of polioviruses in these facilities is associated with their introduction from the outside. The percentage of poliovirus detection in children immunized with OPV was shown to be 16.9 ± 3.4% and was significantly higher than in children vaccinated with IPV (6.1 ± 1.9%). Polioviruses isolated from children immunized with OPV belonged to serotypes 1, 2 and 3 in 19.0, 14.3 and 66.7% of cases, respectively. Polioviruses detected in children immunized with IPV belonged to serotypes 1, 2 and 3 in 30, 40 and 30% of cases, respectively. All the isolated polioviruses turned out to be Sabin vaccine strains. CONCLUSION: Implementation of strict prophylaxis measures in orphanages is necessary in order to prevent the possibility of introduction, transmission and circulation of polioviruses. Improvement of control in children from closed-type facilities will ensure maintenance of Russian Federation status as the country free of poliomyelitis.

[Group enterovirus infection due to coxsackievirus A16 in Northwestern Russia].

AIM: Study features of epidemic process and etiology of oral cavity and limb enterovirus exanthema group diseases in a number of territories of Northwestern Russia. MATERIALS AND METHODS: Isolation and identification of non-poliomyelitis enteroviruses from material of patients was carried out according to WHO recommendations. Phenotyping and phylogenetic analysis of enteroviruses was carried out. RESULTS: In 3 territories of Northwestern Russia oral cavity and limb enterovirus group diseases were registered. Children aged less than 14 years, predominately aged less than 3 years, were shown to be involved in the epidemic process. Coxsackie A16 enteroviruses from 27 samples of patients were isolated in cell cultures and identified by using specific sera. Coxsackie A16 enteroviruses from 16 samples were identified by using partial sequencing of VP1 genome area. Phylogenetic analysis has shown that the identified Coxsackie A16 viruses distributed among 2 phylogenetic groups. CONCLUSION: Coxsackie A16 enteroviruses that had never been detected in the region previously were established to be the etiologic factor of oral cavity and limb enterovirus exanthema group disease in the 3 territories of Northwestern Russia. The data obtained give evidence on the necessity of epidemiologic and virological control for enterovirus infection with the aim of obtaining novel information on the circulation of non-poliomyelitis enteroviruses in the population and the establishment of development patterns for epidemic process of this infection.

Qualitative real-time RT-PCR assay for nOPV2 poliovirus detection.

Based on the success of the Sabin2-based vaccine, a next-generation nOPV2 poliovirus vaccine has been developed. For epidemic monitoring and conducting epidemiological investigations, it is necessary to have a diagnostic assay with the ability to differentiate this variant from others. Here we describe such a real-time RT-PCR assay. The region with the cre insertion in the 5'-UTR was chosen as the target, and the limit of detection was 103 copies/mL (2.5×103 copies/mL using Probit analysis) determined using armored RNA particles. Sensitivity and specificity were 86.28 - 100 % and 76.84 - 100 %, respectively (with 95 % CI). Thus, this method can be effectively used when it is necessary to make a differential diagnosis of poliovirus strains.