Rotavirus Research Articles

BackgroundRotaviruses (RVs) are a leading cause of viral acute gastroenteritis in mammals, including pigs. Infection with porcine RVs can result in a range of clinical outcomes, from asymptomatic cases to severe acute disease. The prevalence of RVs is high in major pork-producing countries but varies by region, age group, and overall animal health. Several studies have assessed Rotavirus A (RVA) and Rotavirus C (RVC) prevalence in suckling piglets in Spain and other regions; however, systematic sampling studies remain limited. This study aimed to determine the true prevalence of RVA and RVC in suckling piglets across Spanish regions and to identify potential risk factors associated with infection.ResultsA total of 563 fecal samples were collected from 106 farms, 84.5% from piglets with diarrhea and 15.5% from healthy piglets from farms without neonatal enteric disorders. RT-qPCR analysis revealed that RVA is a widespread pathogen in suckling piglets, with 43.7% of the samples and 74.5% of the farms testing positive. Conversely, RVC was detected in 25.4% of samples and 44.3% of the farms. The prevalence of RVA was higher in diarrheic piglets than in non-diarrheic ones (46.6% vs. 27.6%). Similarly, RVC prevalence was markedly higher in diarrheic compared to non-diarrheic piglets (29.2% vs. 4.6%). While RVA was detected throughout the lactation period, RVC was more frequently identified during the first week of life. For both viruses, higher viral load and proportion of positive animals were associated with enteric disorders during lactation, while RVC infection specifically correlated with increased mortality. Co-infections of RVA and RVC were relatively rare, suggesting that the presence of one virus may reduce the likelihood of detecting the other. Several risk factors were associated with rotavirus infection, including farm production type, farm size, and the duration of downtime in farrowing units.ConclusionsRVA and RVC are highly prevalent among suckling piglets, with a clear association between infection and diarrhea, particularly when viral loads are high. Farm production type, farm size, and management practices strongly influenced infection risk. These findings provide valuable epidemiological insights into RV infection in piglets and support the development of improved prevention and control strategies.Supplementary InformationThe online version contains supplementary material available at 10.1186/s40813-025-00468-z.

Rotaviruses (RV) are considered significant pathogenic agents responsible for gastroenteritis in humans and various animals, including young birds and mammals. Four RV species – RVA, RVD, RVF, and RVG – exclusively infect avian hosts. In Brazil, RV has been detected in poultry, as well as in domestic and wild birds. This study aimed to standardize protocols for the detection of RVA, RVD, RVF, and RVG in birds using the Multiplex RT-PCR technique. A total of 21 fecal specimens were processed by preparing 10% fecal suspensions in 0.01 M Tris-Ca²⁺ buffer. Viral genomes were subsequently extracted. The Multiplex RT-PCR was performed using specific primers targeting genes of RVA, RVD, RVF, and RVG. Positive RV amplification and validation of the Multiplex RT-PCR were confirmed by 2% agarose gel electrophoresis. Amplicons were then purified and sequenced using the Sanger method. Primer sets were evaluated for specificity and sensitivity, while the Multiplex RT-PCR protocol was assessed for reproducibility, repeatability, and agreement via the Kappa coefficient. All primers were specific, with a detection threshold of 5 × 10⁻7 ng/µL. Reproducibility and repeatability were 91.6% and 93.54%, respectively. The Kappa coefficient was 0.82, indicating an almost perfect level of agreement. Therefore, the developed assays were deemed specific and sensitive tools for the simultaneous detection of RV species infecting avian hosts.

Rotaviruses (RVs) are an important cause of piglet diarrhea. This study aimed to determine the prevalence of rotavirus A, B, and C (RVA, RVB and RVC) in two RVA-vaccinated (VAC) and four non-vaccinated (NON-VAC) farms, and the impact of RVA vaccination on production parameters. Additionally, RVs prevalence in consecutive weekly groups from one vaccinated and one non-vaccinated farm was assessed. Diarrheic feces or ileum content were screened for RVs using real-time RT-PCR. In VAC, no RVA or RVB was detected, while RVC was found in all the samples (15/15). In NON-VAC, RVA, RVB, and RVC were detected in 10.5%, 13.2%, and 52.6% of samples, respectively. RVC was the most prevalent species in longitudinal study, while RVA was found in single samples. RVB was detected in one sample from the vaccinated farm, and in four out of five groups from the non-vaccinated farm. The pre-wean mortality and weaning weight were lower in the vaccinated than in the non-vaccinated farm. Low RVA prevalence and no noticeable improvement in weaning outcomes suggest vaccination was probably unjustified. Our study emphasizes the importance of comprehensive screening before and after vaccination and highlights the importance of including RVB and RVC in diagnostics of neonatal diarrhea.

Rotaviruses (RV) are a group of viruses classified into species A through J, with species A being the best understood. Other RV species infecting animals and humans are less studied due to limited research tools. In RVA, the virus replicates in specialized compartments called viroplasms formed in the cytoplasm by viral proteins, including NSP5, NSP2, and VP2. In this study, we explored how similar structures, termed viroplasm-like structures (VLS), are formed by proteins of RV species A-J. We found that for all tested RV species, NSP5 and VP2 form VLSs. We also identified key regions in the VP2 protein that are essential for forming these structures. Understanding how viroplasms form across different RV species may help develop new strategies to block infection in humans and animals.

Rotavirus (RV) is one of the main etiologic agents associated with diarrheal diseases (DDs), being responsible for approximately 200 thousand deaths annually. Currently, there are still many aspects regarding the virus biology, cell cycle, and pathophysiology of RV that need further elucidation. Therefore, the present work aimed to investigate whether the triggering receptor expressed on myeloid cells 1 (TREM-1) might be associated with RV infection. This immune receptor has been observed as an amplifier of inflammatory responses in different infectious and non-infectious diseases, including inflammatory bowel disease and celiac disease. Initially, we searched for public transcriptomic data regarding RV infection and the expression of TREM-1 and its associated genes, which were significantly upregulated in infected mice and children. Then, we infected monocytes with the virus, with or without a TREM-1 inhibitor. The inhibition of the receptor’s activity resulted in a significant decrease in IL-1β production. We also observed a reduction in cytopathic effects when MA104 cells were treated with TREM-1 inhibitors and then infected with simian RV. To further elucidate the interactions between the virus and TREM-1, in silico tools were used to simulate interactions between the receptor and RV proteins. These simulations suggested the occurrence of interactions between TREM-1 and VP5*, a protein involved in viral attachment to target cells, and also between the receptor and NSP4, a viral enterotoxin with immunostimulant properties. Hence, our results indicate that TREM-1 is involved in RV infection, both as a mediator of inflammatory responses and as a player in the host–virus relationship.

IntroductionRotavirus remains a leading cause of severe gastroenteritis in children globally, including in Ethiopia. Despite the introduction of vaccines, high mutation and reassortment rates contribute to genetic diversity and potential vaccine escape. This study aimed to assess the distribution and genetic characteristics of rotavirus A (RVA) strains in children under five with diarrhea in central Ethiopia, with comparison to the Rotarix® vaccine strain.MethodsStool samples were collected from children under 5 years of age presenting with diarrhea at health centers in Debre Berhan and Addis Ababa between April 2022 and December 2023. RVA was detected using quantitative real-time PCR (qPCR). Genotyping was performed by Sanger sequencing of the VP7 and VP4 genes. Phylogenetic analysis was performed in MEGA X software using the maximum likelihood method with 1,000 bootstrap replicates, using reference sequences retrieved from the GenBank database. Amino acid sequences of these proteins were compared with those of the Rotarix® vaccine strain to identify substitutions in key antigenic regions.ResultsRVA was detected in 30 of 247 samples (12.14%), with 28 successfully genotyped. G9 was the predominant G genotype (50%), followed by G12 (10.2%), G2 (7.1%), G1 (3.6%), and G3 (3.6%); 25% remained untyped. P[4] was the most common P genotype (28.6%), followed by P[6] (21.4%) and P[8] (17.9%), with 32.1% untyped. The most frequent G/P combinations were G9P[4] (35%), G12P[6] (13%), and G9P[8] (9%). Compared to Rotarix®, the circulating G2, G3, G9, and G12 strains showed 18, 12, 13, and 17 amino acid substitutions, respectively, within the 29-residue VP7 epitopes. The P[8], P[4], and P[6] strains exhibited 4, 9, and 18 substitutions, respectively, within the 28 VP4 neutralizing epitope residues. Phylogenetic analysis revealed that the current identified virus mainly clusters with strains previously reported from Ethiopia, indicating a shared evolutionary origin.ConclusionThe dominance of the G9P[4] genotype, together with substantial amino acid substitutions in the current circulating RVA strains that diverge from the G1P[8] Rotarix® strain, may compromise vaccine performance. These findings underscore the need to evaluate vaccine efficacy, maintain molecular surveillance, and incorporate broader genotype coverage in future vaccine design.

BackgroundViral diarrhea is a major global health burden in children. The implementation of unprecedented non-pharmaceutical interventions (NPIs) during the COVID-19 pandemic, including lockdowns, travel restrictions, school closures, enhanced hand hygiene, and mask-wearing, significantly altered the transmission dynamics of many infectious diseases globally. These measures, primarily targeting respiratory pathogens like SARS-CoV-2, were also anticipated to impact the circulation of enteric viruses, which often spread through the fecal–oral route or via contaminated surfaces and aerosols. However, the extent and nature of this impact on the prevalence, seasonality, and genotype distribution of major pediatric enteric viruses including rotavirus (RV), norovirus (NV), adenovirus (ADV), astrovirus (ASV), and sapovirus (SAV) are key pathogens, their molecular epidemiology during the COVID-19 Pandemic remains poorly characterized. This study aimed to delineate the prevalence, genotype distribution, and genetic features of eight enteric viruses in children with acute diarrhea in Hangzhou, China, from March 2019 to December 2020, encompassing phases before and after COVID-19 emergence.MethodsA hospital-based cross-sectional study analyzed 1,510 stool samples from children with acute diarrhea. Eight viruses (RVA, RVB, RVC, NV GI/GII, ADV, ASV, SAV) were detected using qRT-PCR. Positive samples underwent targeted gene sequencing followed by phylogenetic analysis and amino acid mutation screening against reference strains.ResultsEnteric viruses were detected in 33.38% (504/1,510) of samples. NV GII dominated (48.02%, 242/504), with GII.4 as the predominant genotype (84.62%, 88/104). Temporal shifts were observed: for ASV, HAstV-1 replaced HAstV-5 post-2020, and RV G9 persisted as the dominant genotype (47.06%, 8/17) throughout the study period. ADV 41 remained prevalent (97.37%, 37/38), while SAV exclusively showed GI.1 strains. All amino acid mutations matched known variants.ConclusionThis study offers the first molecular epidemiology data on eight enteric viruses in Hangzhou during a period overlapping with COVID-19. The observed genotype shifts, which highlights the need for targeted surveillance.

Complex evolutionary dynamics including reassortment drive genome diversity in human rotavirus species A circulating in Ireland.

Tfh cell-mediated impairment of rotavirus-specific antibodies by PAH and PFAS co-exposure in seropositive children.

The present investigation conducted a 5-year longitudinal survey (August 2018-March 2023) of enteric viruses in bivalve mollusks (n = 390) collected from Golfo Nuevo, Puerto Madryn, Argentina. Samples were processed following ISO 15216-1:2017 guidelines. Norovirus genogroups I/II (NoV GI/GII), rotavirus A (RVA), hepatitis A (HAV) and E (HEV) viruses, and adenovirus (AdV) were detected and quantified by RT-qPCR/qPCR, genotyped, and subjected to phylogenetic analysis. At least one virus was detected in 40.7% of composite samples. AdV exhibited the highest prevalence (56.6%), while NoV GII and RVA were detected in 12.4% of samples; HEV and HAV were detected in 5.3% and 4.4%, respectively, and NoV GI was not detected. Mean viral loads ranged from 4.8 to 6.3 log10 genomic copies/g of bivalve mollusks. Temporal trends revealed a significant decline in detection post-pandemic for RVA, NoV GII, and HAV, while AdV and HEV rates remained stable. Genotyping identified pandemic variant NoV GII.4[P16], RVA G8P[1], HAV IA, and AdV A31. These results provide the first comprehensive baseline of enteric virus contamination in Patagonian shellfish. Routine virus monitoring and evidence-based control measures are therefore imperative to safeguard public health and to align Argentine bivalve mollusks with international safety standards.

Effectiveness of Pentavalent Rotavirus Vaccine - a Propensity Score Matched Test Negative Design Case-Control Study Using Medical Big Data in Three Provinces of China.

Rotaviruses (RVs) induce the formation of cytoplasmic viral factories, termed viroplasms, which are the sites of early particle assembly and viral RNA synthesis. The RV octameric nonstructural protein 2 (NSP2) plays critical, albeit incompletely understood, roles during viroplasm biogenesis. Previous work by our lab demonstrated that a RV bearing a lysine-to-glutamic acid (K294E) change in the flexible C-terminus of NSP2 exhibits defects in viral replication and induces smaller, more numerous viroplasms as compared to the wildtype (WT) virus. In this study, we sought to better understand if/how this K294E amino acid change altered the structure and/or dynamics of the NSP2 protein. We first determined the X-ray crystal structures of untagged, recombinant NSP2K294E and NSP2WT. We found that both proteins formed highly similar octamers and crystallized in the I422 space group. To better understand the possible impacts of the K294E change on the conformations and backbone flexibility of NSP2, we performed molecular dynamics simulations. The results showed that NSP2K294E adopted distinct C-terminal conformations relative to NSP2WT and had subtle flexibility differences. Most notably, the data suggest that the K294E change stabilized a rare C-terminal conformation that was only infrequently sampled by NSP2WT. This shift in conformational preference may help explain why NSP2K294E displayed decreased capacity to mediate robust viroplasm formation during RV infection. These results provide mechanistic insights into how a single amino acid change in the NSP2 C-terminus can have large effects on structural ensemble, shedding light on features of the protein that underpin RV viroplasm formation.

Despite the clinical significance of many nonenveloped viruses, the molecular mechanisms of their internalization and membrane penetration are not well understood. Rotaviruses (RVs) are nonenveloped double-stranded RNA viruses and the leading cause of severe dehydrating diarrhea in infants and young children. We identified fatty acid 2-hydroxylase (encoded by FA2H) in the fatty acid 2-hydroxylation pathway as a proviral gene that supports RV infection. Genetic ablation of FA2H interfered with an early step in RV entry for multiple human and animal strains. Intestinal epithelial cell-specific deletion of Fa2h limited RV replication and diarrhea incidence in vivo. Using transmission electron microscopy and immunofluorescence, we found that viral particles were trapped in early and late endosomes in FA2H knockout cells, preventing their further exit into the cytosol. The defect in RV infectivity could be partially restored by treatment of cells with long-chain 2-hydroxy ceramides or a calcium channel activator that promotes Ca2+ efflux from endosomes. Both Junín virus, an arenavirus, and Shiga toxin, dependent on endosomal Ca2+ transport, required FA2H for efficient entry. Together, this study highlights a role of fatty acid 2-hydroxylation in RV entry into host cells and implicates 2-hydroxy ceramides as potential key regulators of endosomal Ca2+ levels, offering important insights for the development of host-directed therapies targeting fatty acid 2-hydroxylation to control microbial infections.

Interspecies transmission and genome heterogeneity of porcine-originated Rotavirus A between domestic pigs and wildlife in the Croatian ecosystem.

Identification and characterization of the first G8P[1] sheep rotavirus strain in China: Genetic similarity to human rotavirus and zoonotic potential.

This study was undertaken to know the epidemiology of various microorganisms causing gastroenteritis in paediatric age group, to evaluate clinico-microbiological correlation with respect to the type of microorganism, to study the clinical presentations and impact of syndromic based film array assay on antimicrobial stewardship and patient management. This is five years retrospective study in which the results of Gastrointestinal film array panel of stool specimens of children <=16 Years of age who presented with gastroenteritis during 2019 to 2023 were noted. Clinical correlation of the microbes was done with respect to suspected clinical diagnosis, age, immune status and other underlying illness. Out of 151 samples, 41 were negative for all the pathogens and 110 showed presence of one or more pathogens. The occurrence of negative Film array assay in immunocompromised patients was observably more in comparison to immunocompetent patients (36.36% vs 23.36%). Rota virus A and Shigella/Enteroinvasive Escherichia coli (EIEC) were statistically (p value <=0.05) more often detected in immunocompetent patients and children below 5 years of age. The detection of Clostridioides difficile toxin A/B was mainly attributed to transient colonization or asymptomatic carriage in young children. Giardia lamblia and Entamoeba histolytica were more often detected in immunocompetent children. Amongst viruses, Norovirus was detected maximally. Syndromic panel-based detection of pathogens can help in understanding epidemiology of infections, antimicrobial stewardship, setting an example for diagnostic stewardship and may act as a good tool for surveillance of infections thereby leading to timely initiation of preventive strategies.

ObjectiveTo investigate the epidemiological characteristics and climate-sensitive transmission patterns of rotavirus (RV), adenovirus (AdV), and RV-AdV coinfections among children with acute gastroenteritis in Wuhan, China, during the post-COVID-19 era.MethodsWe conducted a retrospective time-series study of 53,088 pediatric patients tested for RV and AdV from April 2020 to August 2024. Age-stratified positivity rates were analyzed alongside temporal trends. Daily meteorological data (temperature, relative humidity, wind speed) and air pollutants were incorporated into a generalized additive model (GAM) framework with distributed lag nonlinear models (DLNMs) to assess delayed and nonlinear associations between weather exposures and virus positivity.ResultsRV was the most frequently detected virus (7.74%), peaking in preschool-aged children (3–6 years), while AdV showed broader age distribution with highest positivity in toddlers (1–3 years). Coinfections were most common in children under 2 years. Significant seasonal and interannual fluctuations were observed, particularly a post-pandemic RV surge in 2024. Spearman analysis revealed inverse correlations between RV/AdV positivity and temperature. DLNMs showed that RV risk increased significantly under low wind (RR = 1.79, lag 0), cold (RR = 1.47, lag 21), and dry conditions (RR = 1.23, lag 15). AdV exhibited a U-shaped humidity-risk curve and increased risk with cold and moderately humid conditions. Coinfection risk was primarily driven by cold temperatures. Significant interactions were found between temperature and wind (RV) and between temperature and humidity (AdV). Season-stratified analysis indicated atypical spring and summer RV peaks.ConclusionThis study is the first in China to apply DLNMs in a large pediatric cohort to evaluate climate-driven risk of RV and AdV infections. Findings reveal pathogen-specific, delayed meteorological sensitivities and post-COVID shifts in transmission patterns, providing a foundation for climate-informed surveillance and targeted interventions in pediatric gastroenteritis control.Supplementary InformationThe online version contains supplementary material available at 10.1186/s12889-025-24010-6.

The infectivity of rotavirus (RV), the leading cause of childhood diarrhea, hinges on the activation of viral particles through the proteolysis of the spike protein by trypsin-like proteases in the host intestinal lumen. In order to determine the structural basis of trypsin activation, we have used cryogenic electron microscopy (cryo-EM) and advanced image processing methods to compare uncleaved and cleaved RV particles. We find that the conformation of the non-proteolyzed spike is constrained by the position of loops that surround its structure, linking the lectin domains of the spike head to its body. The proteolysis of these loops removes this structural constraint, thereby enabling the spike to undergo the necessary conformational changes required for cell membrane penetration. Thus, these loops function as regulatory elements to ensure that the spike protein is activated precisely when and where it is needed to facilitate a successful infection.

Rotavirus (RV) is a major aetiology of childhood gastroenteritis worldwide. It is crucial to understand the hospital-based RV disease prevalence and its spatio-temporal genotype distribution during the period pre-and post-introduction of RV vaccines in India. A systematic review and meta-analysis were performed to extract information on literature related to the impact of vaccination on rotavirus disease prevalence and the distribution of genotypes from 1986 to 2022. A search for relevant articles was carried out in public databases (PubMed, Google Scholar, and ScienceDirect) to extract specific information on RV prevalence among children less than 5years of age and the genotype distribution from 1986 to 2022. DerSimonian-Laird random-effects model was employed to account for the heterogeneity of included studies analysed using meta-analysis and publication bias was assessed using funnel plot and Egger linear regression test. Of the 1939 records identified through screening and after removing duplicate records, the full texts of 1609 records were assessed for eligibility. After the full-text assessment, 49 records were found eligible and included in the study. The estimated pooled prevalence of RV-associated gastroenteritis during the pre-vaccine period was 33% {(95% confidence interval (CI), 28%-38%)} while the prevalence was 23% (95% CI, 18%-29%) in the post-vaccine period. Rotaviruses are classified into genotypes by their G-(glycoprotein VP7) and P-(protease-sensitive VP4) proteins. Combination of genotype G1 and P[8] that is G1P[8] predominated during the pre- and post-vaccine period, while the prevalence of G3P[8] increased after immunisation. The dominant genotypes in pre-vaccine era were G1 and G2 while G1 and G3 after vaccine inclusion, with a constant circulation of P[8] during the entire period from 1986 to 2022. Occurence of G2 increased post-vaccination in western zone of India. As observed from the meta-regression analysis, rotavirus vaccination has significantly reduced gastroenteritis associated hospitalizations and death. The spatio-temporal change in the genotype distribution in the post-vaccination era warrants the need for further surveillance studies to provide information on RV-associated hospital visits. Additionally, this will also provide information on detection of emerging strains that can assist in designing future policies for the implementation and development of new-generation vaccines against rotavirus disease.

The role and implication of rotavirus VP8∗ in viral infection and vaccine development.