A decade of G3P[8] and G9P[8] rotaviruses in Brazil: Epidemiology and evolutionary analyses

Circulating rotavirus strains in children with acute gastroenteritis in Iran, 1986 to 2023 and their genetic/antigenic divergence compared to approved vaccines strains (Rotarix, RotaTeq, ROTAVAC, ROTASIIL) before mass vaccination: Clues for vaccination policy makers

In the present study, first, rotaviruses that caused acute gastroenteritis in children under five years of age during the time before the vaccine was introduced in Iran (1986 to 2023) are reviewed. Subsequently, the antigenic epitopes of the VP7 and VP4/VP8 proteins in circulating rotavirus strains in Iran and that of the vaccine strains were compared and their genetic differences in histo-blood group antigens (HBGAs) and the potential impact on rotavirus infection susceptibility and vaccine efficacy were discussed. Overall data indicate that rotavirus was estimated in about 38.1 % of samples tested. The most common genotypes or combinations were G1 and P[8], or G1P[8]. From 2015 to 2023, there was a decline in the prevalence of G1P[8], with intermittent peaks of genotypes G3P[8] and G9P[8]. The analyses suggested that the monovalent Rotarix vaccine or monovalent vaccines containing the G1P[8] component might be proper in areas with a similar rotavirus genotype pattern and genetic background as the Iranian population where the G1P[8] strain is the most predominant and has the ability to bind to HBGA secretors. While the same concept can be applied to RotaTeq and RotasIIL vaccines, their complex vaccine technology, which involves reassortment, makes them less of a priority. The ROTASIIL vaccine, despite not having the VP4 arm (P[5]) as a suitable protection option, has previously shown the ability to neutralize not only G9-lineage I strains but also other G9-lineages at high titers. Thus, vaccination with the ROTASIIL vaccine may be more effective in Iran compared to RotaTeq. However, considering the rotavirus genotypic pattern, ROTAVAC might not be a good choice for Iran. Overall, the findings of this study provide valuable insights into the prevalence of rotavirus strains and the potential effectiveness of different vaccines in the Iranian and similar populations.

Norovirus and rotavirus infections in children less than five years of age hospitalized with acute gastroenteritis in Indonesia

Rotaviruses and noroviruses are the most important viral causes of acute gastroenteritis in children. While previous studies of acute gastroenteritis in Indonesia mainly focused on rotavirus, here, we investigated the burden and epidemiology of norovirus and rotavirus disease. Children less than five years of age hospitalized with acute gastroenteritis were enrolled in this study from January to December 2015 at three participating hospitals. Rotavirus was detected by enzyme immunoassay (EIA), followed by genotyping by reverse transcription PCR (RT-PCR). Norovirus genogroups were determined by TaqMan-based quantitative RT-PCR. Among 406 enrolled children, 75 (18.47%), 223 (54.93%) and 29 (7.14%) cases were positive for norovirus, rotavirus and both viruses (mixed infections), respectively. Most cases clinically presented with fever, diarrhea, vomiting and some degree of dehydration. The majority (n = 69/75 [92%]) of the noroviruses identified belonged to genogroup II, and several genotypes were identified by sequencing a subset of samples. Among 35 samples tested for rotavirus genotype, the most prevalent genotype was G3P[8] (n = 30/35 [85.6%]). Our study suggests that the burden of norovirus diseases in Indonesian children should not be underestimated. It also shows the emergence of rotavirus genotype G3P[8] in Indonesia.

Genotypic and epitope characteristics of group A porcine rotavirus strains circulating in Canada

Surveillance of Rotavirus A (RVA) infections in North America swine populations are limited and not performed over a significant time period to properly assess the diversity of RVA strains in swine. The VP7 (G) and VP4 (P) genes of 32 Canadian RVA strains, circulating between 2009 and 2015 were sequenced, identifying the G3P[13], G5P[7], G9P[7], G9[13], and G9[19] genotype combinations. The Canadian RVA strains were compared to the RVA strains present in the swine ProSystems RCE rotavirus vaccine. The comparison revealed multiple amino acid differences in the G and P antigenic epitopes, regardless of the G and P genotypes but specifically in the Canadian G3, P[13] and P[19] genotypes. Our study further contributes to the characterization of RVA's evolution and disease mitigation among swine, which may optimize target vaccine design, thereby minimizing RVA disease in this economically important animal population.

Detection of Common, Emerging and Uncommon VP4, and VP7 Human Group A Rotavirus Genotypes from Urban Sewage Samples in Uruguay

Environmental approach has proven to be a useful tool for epidemiological studies demonstrating through environmental studies the diversity of viruses circulating in a given population. The aim of this study was to perform a phylogenetic characterization of the group A rotavirus (RVA) glycoprotein (G)- and protease-sensitive (P)-genotypes obtained from sewage samples (n = 116) collected in six cities of Uruguay during March 2011 to April 2013. A worldwide standardized semi-nested multiplex RT-PCR (SNM RT-PCR) protocol directed against VP4 and VP7 genes were conducted for RVA detection and consensual DNA fragments were submitted to nucleotide sequencing. P and/or G genotype was successfully determined by phylogenetic analysis in 61% (n = 37) of the positive samples obtained by SNM RT-PCR (n = 61). The RVA genotypes were as follow: G1 (n = 2), G2 (n = 14), G3 (n = 5), G12 (n = 2), P[4] (n = 4), P[8] (n = 16), and P[3] (n = 2). Interestingly, through phylogenetic analysis, emerging, and uncommon human genotypes could be detected. Results obtained from the comparison of RVA genotypes detected in the current study and Uruguayan RVA strains previously described for contemporary clinical pediatric cases showed that monitoring sewage may be a good screening option for a rapid and economical overview of the circulating genotypes in the surrounding human population and a useful approximation to study RVA epidemiology in a future vaccine monitoring program. The present study represents the first report in Uruguay that describes the phylogenetic diversity of RVA from urban sewage samples.