Prevalence and Genetic Diversity of Group A Rotavirus Genotypes in Moscow (2019-2020)

Systematic literature review and meta-analysis on the prevalence of rotavirus genotypes in Europe and the Middle East in the post-licensure period

Previous systematic literature reviews of rotavirus genotype circulation in Europe and the Middle East are limited because they do not include country-specific prevalence data. This study documents country-specific evidence on the prevalence of rotavirus genotypes in Europe and the Middle East to enable more precise epidemiological modeling and contribute to the evidence-base about circulating rotavirus genotypes in the post-vaccination era. This study systematically searched PubMed, Embase and Scopus for all empirical epidemiological studies that presented genotype-specific surveillance data for countries in Europe and the Middle East published between 2006 and 2021. The STROBE checklist was used to assess the quality of included studies. Proportional meta-analysis was conducted using the generic inverse variance method with arcsine transformation and generalized linear-mixed models to summarize genotype prevalence. Our analysis estimated the genotype prevalence by country across three date categories corresponding with rotavirus seasons: 2006-2010, 2011-2015, 2016-2021. A total of 7601 deduplicated papers were identified of which 88 studies were included in the final review. Rotavirus genotypes exhibited significant variability across regions and time periods, with G1P[8], G2P[4], G3P[8], G4P[8], G9P[8], and, to a lesser extent G12P[8], being the most prevalent genotypes through different regions and time-periods. Uncommon genotypes included G3P[9] in Poland, G2P[6] in Iraq, G4P[4] in Qatar, and G9P[4] as reported by the European Rotavirus Network. There was high genotype diversity with routinely identified genotypes being G1P[8], G2P[4], G3P[8], G4P[8], and G9P[8]; there was high variability across time periods and regions. Continued surveillance at the national and regional levels is relevant to support further research and inform public health decision-making.

Complete genome characterization by nanopore sequencing of rotaviruses A, B, and C circulating on large-scale pig farms in Russia

BACKGROUND

Rotaviruses are the major etiological agents of gastroenteritis and diarrheal outbreaks in plenty of mammalian species. The genus Rotavirus is highly diverse and currently comprises nine genetically distinct species, and four of them (A, B, C, and H) are common for humans and pigs. There is a strong necessity to comprehend phylogenetic relationships among rotaviruses from different host species to assess interspecies transmission, specifically between humans and livestock. To reveal the genetic origin of rotaviruses from Russian pig farms, nanopore-based metagenomic sequencing was performed on the PCR-positive specimens.

METHODS

Samples were selected among the cases submitted to routine diagnostic or monitoring studies to the Laboratory of Biochemistry and Molecular Biology of "Federal Scientific Center VIEV" (Moscow, Russia). The selected positive samples were genotyped using nanopore sequencing method.

RESULTS

Five porcine RVA isolates were completely sequenced, and genotype analysis revealed various porcine G/P genogroups: G2, G3, G4, G5, G11 and P[6], P[7], P[13], P[23], P[27] with a typical backbone constellation I5-R1-C1-M1-A8-N1-T1/7-E1-H1. The RVB isolate was detected in combination with RVA in a rectal swab from a diseased pig in Krasnoyarsk Krai. It was characterized by the following genogroups: G15-P[X]-I11-R4-C4-M4-A8-N10-T4-E4-H7. The first complete porcine RVC genome from Russia was obtained with genomic constellation G6-P[5]-I14-R1-C1-M1-A7-N9-T6-E1-H1, and the phylogenetic analysis revealed putative novel genotype group for the VP6 gene-I14. Additionally, the first porcine kobuvirus isolate from Russia was phylogenetically characterized.

CONCLUSIONS

The applied nanopore sequencing method successfully genotyped the RV isolates and additionally revealed co-circulated species. The study demonstrates high genetic variability of Russian RVA isolates in VP4/VP7 genes and phylogenetically describes local RVB and RVC. Complete characterization of genomic segments is a crucial methodology in tracing the rotavirus's evolution and evaluating interspecies transmissions.

Emergence and dissemination of equine-like G3P[8] rotavirus A in Brazil between 2015 and 2021

Rotavirus A (RVA) is a major cause of acute gastroenteritis globally that is classically genotyped by its two immunodominant outer capsid proteins, VP7 (G-) and VP4 (P-). Recent evidence suggests that the reassortant equine-like G3P[8] strain played a substantial role in RVA transmission in Brazil since 2015. To understand its global emergence and dissemination in Brazilian territory, stool samples collected from 11 Brazilian states (n = 919) were genotyped by RT-qPCR and proceeded to sequence the VP7 gene (n = 102, 79 being newly generated) of the G3P[8] samples with pronounced viral loads. Our phylogenetic genotyping showed that G3P[8] became the dominant strain in Brazil between 2017 and 2020, with equine-like variants representing 75%-100% of VP7 samples in this period. A Bayesian discrete phylogeographic analysis strongly suggests that the equine-like G3P[8] strain originated in Asia during the early 2010s and subsequently spread to Europe, the Caribbean, and South America. Multiple introductions were detected in Brazil between 2014 and 2017, resulting in five national clusters. The reconstruction of the effective population size of the largest Brazilian cluster showed an expansion until 2017, followed by a plateau phase until 2019 and subsequent contraction. Our study also supports that most mutations fixed during equine-like G3P[8] evolution were synonymous, suggesting that adaptive evolution was not an important driving force during viral dissemination in humans, potentially increasing its susceptibility to acquired immunity. This research emphasizes the need for comprehensive rotavirus genomic surveillance that allows close monitoring of its ever-shifting composition and informs more effective public health policies.IMPORTANCEOur original article demonstrated the origin and spread in a short time of equine-like G3P[8] in Brazil and the world. Due to its segmented genome, it allows numerous mechanisms including genetic drift and reassortment contribute substantially to the genetic diversity of rotavirus. Although the effectiveness and increasing implementation of vaccination have not been questioned, a matter of concern is its impact on the emergence of escape mutants or even the spread of unusual strains of zoonotic transmission that could drive epidemic patterns worldwide. This research emphasizes the need for comprehensive rotavirus genomic surveillance, which could facilitate the formulation of public policies aimed at preventing and mitigating its transmission.

Phylodynamic characteristics of reassortant DS-1-like G3P[8]-strains of rotavirus type A isolated in Nizhny Novgorod (Russia)

Since 2013, there has been an increase in reports of the spread of a double intergroup reassortant strain of rotavirus type A (RVA) with the genotype G3P[8] and other genes belonging to the second genogroup I2-R2-C2-M2-A2-N2-T2-E2-H2. In our study, we provide a molecular genetic characterization of rotaviruses with genotype G3P[8]-I2 isolated in Nizhny Novgorod. In our study, we used RT-PCR, Sanger sequencing, RNA-PAGE methods. Phylogenetic and phylodynamic analysis were performed using the Bayesian approach. According to our study, there was a significant increase in the proportion of G3P[8] from 15% during the period of 2020-2021 to 53% during the period of 2021-2022 in Nizhny Novgorod, Russia. Phylogenetic analysis based on the VP4 gene revealed that DS-1-like RVAs isolated in Nizhny Novgorod belong to different clusters of the P[8]-3.1 lineage, with a level of variation ranging from 1.1% to 1.3%. Based on the VP6 gene, the equine-like RVAs identified by us carry genetic variants belonging to three distinct clusters of the lineage I2-V, with a variation level ranging from 2.0% to 4.5%. These data indicate the genotypic diversity of circulating DS-1-like G3 RVAs. Phylogenetic analysis of the VP7 gene allowed us to assign the isolates identified in our study to the G3-1 lineage. We estimated that the circulation of the most recent common ancestor of the spreading strains dates back to 2002. Additionally, we determined the typical level of mutations in the VP7 gene, which amounted to 2.14*10-3 substitutions/per site/per year.

[Study of the safety and immunogenicity of VLP-based vaccine for the prevention of rotavirus infection in neonatal minipig model]

INTRODUCTION

In Russia, almost half of the cases of acute intestinal infections of established etiology in 2022 are due to rotavirus infection (RVI). There is no specific treatment for rotavirus gastroenteritis. There is a need to develop modern, effective and safe vaccines to combat rotavirus infection that are not capable of multiplying (replicating) in the body of the vaccinated person. A promising approach is to create vaccines based on virus-like particles (VLPs).

OBJECTIVE

Study of the safety and immunogenicity of a vaccine against rotavirus infection based on virus-like particles of human rotavirus A in newborn minipigs with multiple intramuscular administration.

MATERIALS AND METHODS

Newborn minipigs were used as an animal model in this study. The safety of the tested vaccine was assessed based on thermometry data, clinical examination, body weight gain, clinical and biochemical blood parameters, as well as necropsy and histological examination. When studying the immunogenic properties of the Gam-VLP-rota vaccine in doses of 30 and 120 µg, the cellular, humoral and secretory immune response was studied.

RESULTS

The results of assessing the general condition of animals during the immunization period, data from clinical, laboratory and pathomorphological studies indicate the safety of the vaccine against human rotavirus infection based on VLP (Gam-VLP-rota) when administered three times intramuscularly. Good local tolerance of the tested vaccine was demonstrated. The results of the assessment of humoral immunity indicate the formation of a stable immune response after three-time immunization with Gam-VLP-rota, stimulation of the production of antigen-specific IgG antibodies and their functional activity to neutralize human rotavirus A. It was shown that following the triple immunization with the minimum tested concentration of 30 µg/dose, animals developed a cell-mediated immune response. The results of the IgA titer in blood serum and intestinal lavages indicate the formation of both a systemic immunological response and the formation of specific secretory immunity to human rotavirus A.

CONCLUSION

Thus, three-time intramuscular immunization of minipigs with the Gam-VLP-rota vaccine forms stable protective humoral and cellular immunity in experimental animals. Evaluated vaccine is safe and has good local tolerability.

Human rotavirus strains circulating among children in the capital of China (2018-2022)_ predominance of G9P[8] and emergence ofG8P[8]

OBJECTIVE

This study aimed to update the genetic diversity of Rotavirus (RV) infections in children under five years old in Beijing, China.

METHODS

A 5-year active hospital-based surveillance for sporadic acute gastroenteritis (AGE) from January 2018 to December 2022 in the capital of China was performed. A total of 748 fecal samples from AGE patients were collected for followed by RV antigen detection by ELSIA, RNA detection by reverse transcription PCR, G/P genotyping and phylogenetic analyzing.

RESULTS

RV antigen was detected in 11.0% of the collected samples, with 54 samples confirmed to be RV RNA positive. G9 and G8 genotypes were identified in 43 (79.6%) and 7 (13.0%) samples, respectively, all of which were allocated to P[8]. The predominant G/P combination was G9P[8] (79.6%), following by G8P[8] (13.0%), G4P[8] (5.6%) and G3P[8] (1.9%). A significant change in G/P-type distribution was observed, with the G9P[8] being predominant from 2018 to 2021, followed by the emergence of an uncommon G8P[8] genotype, which was first reported in 2021 and became predominant in 2022. Blast analysis showed that one G1 isolate had a high similarity of 99.66% on nucleotide acid with RotaTeq vaccine strain with only one amino acid difference L150V. Additionally, one P[8] isolate was clustered into a branch together with RotaTeq vaccine strain G6P[8].

CONCLUSIONS

The study reveals that G8P[8] has become the predominant genotype in pediatric outpatients in China for the first time, indicating a significant change in the composition of RV genetic diversity. The importance of RVA genotyping in surveillance is emphasized, as it provides the basis for new vaccine application and future vaccine efficacy evaluation.

The Effect of Virus-Specific Vaccination on Laboratory Infection Markers of Children with Rotavirus-Associated Acute Gastroenteritis

Objective: Rotavirus (RV) is one of the most common and important causes of acute gastroenteritis (AGE) in newborns and children worldwide. The aim of this study was to evaluate the effect of the RV vaccine on the natural history of RV infections using the neutrophil–lymphocyte ratio (NLR), platelet–lymphocyte ratio (PLR), and systemic immune inflammatory index (SII) as hematological indexes, clinical findings, and hospitalization. Method: Children aged 1 month to 5 years who were diagnosed with RV AGE between January 2015 and January 2022 were screened, and 630 patients were included in the study. The SII was calculated by the following formula: neutrophil × platelet/lymphocyte. Results: Fever and hospitalization were significantly higher and breastfeeding was significantly lower in the RV-unvaccinated group than in the RV-vaccinated group. The NLR, PLR, SII, and CRP were significantly higher in the RV-unvaccinated group (p < 0.05). The NLR, PLR, and SII were significantly higher both in the non-breastfed group than in the breastfed group and in the hospitalized group than in the not hospitalized group (p < 0.05). CRP was not significantly different in either the hospitalization group or the breastfeeding group (p > 0.05). SII and PLR were significantly lower in the RV-vaccinated group than in the RV-unvaccinated group in both the breastfed and non-breastfed subgroups. For NLR and CRP, while there was no significant difference according to RV vaccination status in the breastfed group, there was a significant difference in the non-breastfed group (p value: <0.001; <0.001). Conclusions: Despite the low level of vaccine coverage, the introduction of RV vaccination had a positive impact on the incidence of RV-positive AGE and related hospitalizations in children. These results showed that breastfed and vaccinated children were less prone to inflammation because their NLR, PLR, and SII ratios were lower. The vaccine does not prevent the disease 100%. However, it can prevent severe disease with exsiccation or death.

Molecular epidemiological characteristics of the virus in 96 children with acute diarrhea in Changdu of Tibet, China

OBJECTIVES

To study the molecular epidemiological characteristics of the virus in children with acute viral diarrhea in Changdu of Tibet, China.

METHODS

Fecal specimens were collected from 96 children with acute diarrhea who visited the People's Hospital of Changdu, Tibet, from November 2018 to November 2020 and were tested for adenovirus, norovirus, astrovirus, sapovirus, and rotavirus. Gene sequencing was performed for the genotypes of these viruses.

RESULTS

The overall positive rate of the five viruses was 39% (37/96), among which astrovirus had the highest positive rate of 17%, followed by norovirus (9%), rotavirus (8%), adenovirus (7%), and sapovirus (5%). There was no significant difference in the positive rate of the five viruses among different age groups (P>0.05). Only the positive rate of astrovirus was significantly different among the four seasons (P<0.05). For adenovirus, 6 children had F41 type and 1 had C2 type; for norovirus, 6 had GⅠ.3 type, 1 had GⅠ.7 type, 1 had GⅡ.3 type, and 2 had GⅡ.4 Sydney_2012 type; HAstrV-1 type was observed in all children with astrovirus infection; for sapovirus, 1 child each had sporadic GⅠ.2, GⅠ.6, and GⅡ.1 sapovirus and 2 children had unknown type; 6 children had rotavirus G9[P8].

CONCLUSIONS

Astrovirus and norovirus are important pathogens in children with acute diarrhea in Changdu, Tibet. The positive rate of adenovirus, norovirus, astrovirus, sapovirus, and rotavirus is not associated with age, and only the positive rate of astrovirus has obvious seasonality. F41 type is the dominant genotype of adenovirus; GⅠ.3 is the dominant genotype of norovirus; HAstrV-1 is the dominant genotype of astrovirus; sporadic GⅠ.2, GⅠ.6, and GⅡ.1 are the dominant genotypes of sapovirus; G9[P8] is the dominant genotype of rotavirus.