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.

Rotaviruses are non-enveloped double-stranded RNA virus that causes acute diarrheal diseases in children (< 5 years). More than 90% of the global rotavirus infection in humans was caused by Rotavirus group A. Rotavirus infection has caused more than 200000 deaths annually and predominantly occurs in the low-income countries. Rotavirus evolution is indicated by the strain dynamics or the emergence of the unprecedented strain. The major factors that drive the rotavirus evolution include the genetic shift that is caused by the reassortment mechanism, either in the intra- or the inter-genogroup. However, other factors are also known to have an impact on rotavirus evolution. This review discusses the structure and types, epidemiology, and evolution of rotaviruses. This article also reviews other supplemental factors of rotavirus evolution, such as genetic reassortment, mutation rate, glycan specificity, vaccine introduction, the host immune responses, and antiviral drugs.

Rotavirus molecular surveillance remains important in the postvaccine era to monitor the changes in transmission patterns, identify vaccine-induced antigenic changes and discover potentially pathogenic vaccine-related strains. The Canadian province of Alberta introduced rotavirus vaccination into its provincial vaccination schedule in June 2015. To evaluate the impact of this program on stool rotavirus positivity rate, strain diversity, and seasonal trends, we analyzed a prospective cohort of children with acute gastroenteritis recruited between December 2014 and August 2018. We identified dynamic changes in rotavirus positivity and genotype trends during pre- and post-rotavirus vaccine introduction periods. Genotypes G9P[8], G1P[8], G2P[4], and G12P[8] predominated consecutively each season with overall lower rotavirus incidence rates in 2016 and 2017. The demographic and clinical features of rotavirus gastroenteritis were comparable among wild-type rotaviruses; however, children with G12P[8] infections were older (p < 0.001). Continued efforts to monitor changes in the molecular epidemiology of rotavirus using whole genome sequence characterization are needed to further understand the impact of the selection pressure of vaccination on rotavirus evolution.

Acute gastroenteritis is the cause of considerable mortality and morbidity worldwide, particularly among children under five years in underdeveloped countries. Most acute gastroenteritis (AGE) cases are attributed to viral etiologies, including rotavirus, norovirus, adenovirus, astrovirus, and sapovirus. This paper aimed to determine the prevalence rate of different viral etiologies of AGE in the Middle East and North Africa (MENA) region. Moreover, this paper explored rotavirus phylogenetic relatedness, compared VP7 and VP4 antigenic regions of rotavirus with vaccine strains, and explored the availability of vaccines in the MENA region. The literature search identified 160 studies from 18 countries from 1980 to 2019. The overall prevalence of rotavirus, norovirus, adenovirus, astrovirus, and sapovirus were 29.8 %, 13.9 %, 6.3 %, 3.5 %, and 3.2 % of tested samples, respectively. The most common rotavirus genotype combinations in the MENA region were G1P[8], G9P[9], and G2P[4], whereas GII.4 was the predominant norovirus genotype all of which were reported in almost all the studies with genotyping data. The comparison of VP7 and VP4 between circulating rotavirus in the MENA region and vaccine strains has revealed discrete divergent regions, including the neutralizing epitopes. Rotavirus vaccine was introduced to most of the countries of the MENA region; however, only a few studies have assessed the effectiveness of vaccine introduction. This paper provides a comprehensive update on the prevalence of the different viral agents of AGE in the MENA region.

G12 strains are now considered to be the sixth most prevalent human rotaviruses globally. India has introduced rotavirus vaccine Rotavac® into the national immunization program in 2016 and Himachal Pradesh (HP) is the first state to launch it. During epidemiological rotavirus surveillance in HP, predominance of G12 rotaviruses was observed. This study investigated the genetic variability and evolution of HP G12 strains (n = 15) associated with P-genotypes P[6], P[4], and P[8] identified between 2013 and 2016. Phylogenetic analysis of VP7 gene revealed that all characterized G12 strains clustered in lineage-III and diversified into three subclusters indicating that these strains may have originated from three different ancestral G12 strains. The comparative sequence analysis of HP strains with Rotavac® and Rotarix® vaccine strains revealed various amino acid substitutions in epitope regions of VP7 and VP4 proteins especially at the antibody neutralization sites. Only 12/29 VP7 epitope residues and 2/25 VP4 epitope residues were found to be conserved between HP rotavirus strains and vaccine strains. Both long and short electropherotypes were observed in G12P[4] strains, while a single long electropherotype was observed in G12P[6] strains. Children of ≤11 months were significantly infected with G12 rotaviruses. The frequency of vomiting episodes (≥5/day) was significantly higher in children infected with G12 rotavirus strains as compared to non-G12 rotaviruses (p = 0.0405). Our study provides the comprehensive data on clinical characteristics and evolutionary pattern of the G12 rotavirus, the most prevalent strain in HP and emphasizes the need to monitor these strains for inclusion in future vaccine.

The University of the Free State - Next Generation Sequencing (NGS) Unit, Bloemfontein, South Africa, hosted a data and bioinformatics workshop from 19 to 22 June 2018. The workshop was coordinated by the African Enteric Viruses Genome Initiative (AEVGI) with support from the Bill & Melinda Gates Foundation. The event introduced technologies in NGS and data analysis with focus on the rotavirus (RV) genome. The workshop fostered interactions and networking between professionals, scientific experts, technicians and students. The courses provided an overview of RV diarrhoea and its burden in Africa, while highlighting the key resources and methodologies in NGS and advanced bioinformatics in deciphering vaccine impact. It was concluded that, despite the reported significant decline in RV associated-diarrhoea mortality and morbidity in Africa due to RV vaccine impact, the need for continuous surveillance and genomic characterization to better understand the ever-changing dynamics of RV strains is imperative.