Norovirus Genotypes That Caused Cases of Acute Gastroenteritis in the Khabarovsk Region

Background: Noroviruses are common causative agents of acute gastroenteritis worldwide. Person-to-person transmission is the dominant transmission route for norovirus infection but contaminated water also often leads to outbreaks. Objectives: Our purpose was to do epidemiologic and molecular genetic analyses of waterborne norovirus infection outbreak among children in Khabarovsk in 2019. Materials and methods: Clinical and water samples were screened for the presence of norovirus RNA using real-time RT-PCR detection kit. The norovirus nucleotide sequences were determined by Sanger sequencing. The obtained sequences were subjected to a phylogenetic analysis. Results: In July 2019, 34 children developed acute gastroenteritis in Khabarovsk. The epidemiologic investigation showed that on the eve of the disease onset all patients played and bathed in a pedestrian fountain complex. A molecular genetic analysis of 18 biological samples from children with acute gastroenteritis and a water sample from the fountain revealed a recombinant norovirus GII.P7-GII.6. We established a 100.0% identity of all obtained nucleotide sequences to each other. A phylogenetic analysis of ORF2 partial sequences showed that the capsid protein of the Khabarovsk GII.P7-GII.6 strains belonged to the variant GII.6a. Conclusions: Contaminated water in the pedestrian interactive fountain complex was the most likely cause of the norovirus infection outbreak among children in Khabarovsk in 2019 associated with the lack of proper maintenance and regular disinfection measures.

unclassified

Waterborne Outbreak of Acute Gastroenteritis Caused by Recombinant Norovirus GII.P7–GII.6 in Khabarovsk in 2019

Бутакова¹,

Сапега²,

Троценко³

et al. 2020

Monitoring of Infectious and Parasitic Diseases in Chukotka Autonomous District

Ковшов¹,

Novikova²,

Fedorov³

et al. 2019

We studied the dynamics and structure of the incidence of some infectious and parasitic diseases in Chukotka (codes for ICD-10 A00-B99) during the 2000–2017 period, the levels and structure of mortality due to some infectious and parasitic diseases. We used materials from the forms of federal statistical observation No. 2 «Information on infectious and parasitic diseases», No. 12 «Information on the number of diseases registered in patients living in the service area of the medical establishment» and materials of Russian Federal State Statistics Service. The results of the monitoring indicate an increased incidence of infectious and parasitic diseases on the territory of Chukotka Autonomous District compared to Russia. Chicken pox prevails, acute intestinal infections (mainly of unspecified etiology) followed with a significant margin. There was a sharp increase in newly detected cases of active tuberculosis in Chukotka over the last 10 years. The incidence rate in Chukotka was in 4.2 times higher in 2018 than the average ones in Russia. We suppose that the real incidence rates, especially of parasitic diseases, are even higher. Therefore, it is necessary to improve the system of diagnosis, registration of these diseases, especially in rural areas, to develop adequate measures to manage the incidence of infectious and parasitic diseases.

Assessment of Genetic Diversity of Noroviruses Circulating in Temporary Accommodation Centers for Refugees in the Rostov Region in 2022 Using the NoroNetRus Online Software

Водопьянов¹,

Pisanov²,

Водопьянов³

et al. 2022

Introduction: It is obvious that effective investigation of norovirus outbreaks is impossible without the use of methods enabling differentiation of pathogen genotypes, the principal of which is the determination of the type of capsid and polymerase based on sequencing data. Yet, unstable operation of international services for assessment of norovirus genomes from a number of IP addresses located in the Russian Federation has been noted recently, which may affect the efficiency and promptness of inves- tigation of norovirus outbreaks in our country. Objective: To develop domestic software for genotyping of noroviruses and further assessment of genetic diversity of norovi- ruses identified in the year 2022 in the Rostov Region. Materials and methods: The materials for the study were stool samples from 210 patients with symptoms of gastrointestinal infec- tions from temporary accommodation centers for refugees and children’s centers. The study population included patients aged 1 month to 74 years with symptoms of acute bowel infections. Detection of the pathogen RNA was carried out using a reagent kit AmpliSens® OKI screen-FL (Moscow, Russia). Fragment sequencing was performed using a genomic analyzer SeqStudio (Thermo Fisher, USA). The authors’ software was developed in the Java and Python programming languages. Results: We developed a domestic NoroNetRus software allowing determination of the type of capsid and polymerase of noroviruses based on sequencing data. The software is free of charge and available online at http://antiplague.ru/noronetrus. The fragment analysis of VP1 gene sequences for 25 norovirus samples showed that they belonged to three different genotypes (GII.4 Sydney, GII.10, and GII.17), and the genotype GII.10, in its turn, was distributed between two different clusters. Our findings indicate the existence of at least four different sources of infection. Conclusion. The data obtained indicate the circulation of at least four different genovariants of the causative agent of norovirus infection in the Rostov Region in 2022.