[Analysis of the relationship between intestinal segmented filamentous bacteria and rotavirus infection in children].

Objective: To investigate the association between intestinal colonization of segmented filamentous bacteria (SFB) and the risk of rotavirus infection, and the possible mechanisms by which SFB resist rotavirus infection. Methods: This case-control study enrolled 50 children aged 0 to 5 years who present to the outpatient Department of Children's Hospital, Zhejiang University School of Medicine with diarrhea and positive stool tests for rotavirus. The children were divided into rotavirus enteritis group and control group consisting of 55 children with non-gastrointestinal and non-infectious surgical diseases.The age and sex composition of the two groups was matched. The DNA of the fecal flora was extracted and SFB was detected by real-time fluorescence quantitative PCR analysis. The children in the rotavirus enteritis group and the control group were subgrouped by age and sex to analyze the differences in SFB positivity rates between different groups, and further compare and analyze the differences in SFB positivity rates between these two groups of children in the ≤2 years old subgroup and the >2-5 years old subgroup. Neutralization test was performed with p3340 protein and rotavirus to determine the relationship between rotavirus infection rate and p3340 concentration in Vero cells. χ2 test or Fisher's exact probability method was used for comparison between the two groups. Results: There were 50 children in the rotavirus enteritis group with an age of (1.7±0.9) years, and 55 children in the control group with an age of (1.8±1.1) years. The positive rate of SFB in children with rotavirus enteritis showed a declining trend across ages groups, with the highest rate of 10/14 in the ≤1 year old group, followed by 67% (14/21) in the >1-2 years old group, 9/15 in the >2-5 years old group, and there was no statistically significant difference (P=0.867). The positive rate of SFB in the control group was 12/15 in the ≤1 year old group, 95% (19/20) in the >1-2 years old group, 50% (10/20) in the >2-5 years old group, with statistical significance (P=0.004). The positive rate of SFB in children with rotavirus enteritis was 74% (20/27) in males and 56% (13/23) in females (χ2=1.71, P=0.192). In the control group, it was 79% (22/28) in males and 70% (19/27) in females (χ2=0.49, P=0.485). The positive rate of SFB was 66% (33/50) in the rotavirus enteritis group and 75% (41/55) in the control group, with no statistically significant (χ2=0.56, P=0.454). In the children ≤2 years old, the SFB positivity rate was 69% (24/35) in the rotavirus enteritis group and 89% (31/35) in the control group, with a statistically significant difference (χ2=4.16, P=0.041). However, in the children >2-5 years old, no statistically significant difference was observed, with the positive rate of SFB being 9/15 in the rotavirus enteritis group and 50% (10/20) in the control group (P=0.734). Pearson correlation analysis revealed a negative correlation between rotavirus infection and SFB positivity (r=-0.87,P<0.001). As the concentration of the p3340 specific protein increased, the luminescence intensity of the luciferase in the Vero cells, which were suitable for cultivating rotavirus, exhibited a decreasing trend (F=4.17, P=0.001). Conclusions: SFB colonization in infants less than 2 years old is associated with a reduced risk of rotavirus infection. Cloning of specific SFB functional protein p3340 neutralizes rotavirus infection of Vero cells, and this mechanism of targeting rotavirus infection differs from the common antiviral mechanism.

The course of Rotavirus A (RVA) infection in young racing pigeons during the racing season.

BACKGROUND: Pigeon Rotavirus A (RVA) infection has been confirmed in pigeons in the last decade as a cause of Young Pigeon Disease (YPD). Although YPD has been known for many years to date, no studies have been conducted to track the spread of RVA infection in pigeons during the racing season. The presented research aims to determine the course of RVA infection during the flights of young racing pigeons in the summer season, in one of the districts in the Mazovian Voivodeship in Poland. RESULTS: Faecal samples of pigeons collected from transport baskets in vehicles transporting pigeons to the starting point were tested. The quantitative RT-PCR (qRT-PCR) was used to detect the genetic material of RVA. Samples taken during 6 flights were analysed. The study showed a percentage increase in infections up to the fourth flight of pigeons, and then their decrease. With Cq values below 20, breeders did not participate in the next flight and/or reported disease in the flock. With positive Cq values of 20 to 30, clinical signs of disease were not reported. Of the 76 breeders participating in the races, at least one positive result was found in 46 (60.5%). Including the occurrence of the disease during the racing season was reported by 11 breeders (14.4%). The main clinical signs in sick pigeons were vomiting, diarrhea and stowed crop. The tested pigeons were not vaccinated against RVA. CONCLUSIONS: During training and racing of pigeons, it is not possible to avoid exposing them to pathogens, including RVA, regardless of whether pigeons from different breeders are placed in the same baskets or are in separate baskets. However, after four flights the number of new cases of the disease decreases which indicates the development of immunity. The qRT-PCR test is useful in the diagnosis and differentiation of clinical (Cq below 20) and subclinical RVA infections in racing pigeons.

Epidemiological Characteristics and Genotypic Features of Rotavirus and Norovirus in Jining City, 2021-2022.

Diarrhea, often caused by viruses like rotavirus (RV) and norovirus (NV), is a global health concern. This study focuses on RV and NV in Jining City from 2021 to 2022. Between 2021 and 2022, a total of 1052 diarrhea samples were collected. Real-Time Quantitative Fluorescent Reverse Transcriptase-PCR was used to detect RV-A, NV GI, and NV GII. For RV-A-positive samples, VP7 and VP4 genes were sequenced for genotype analysis, followed by the construction of evolutionary trees. Likewise, for NV-GII-positive samples, VP1 and RdRp genes were sequenced for genotypic analysis, and evolutionary trees were subsequently constructed. Between 2021 and 2022, Jining City showed varying detection ratios: RV-A alone (excluding co-infection of RV-A and NV GII) at 7.03%, NV GI at 0.10%, NV GII alone (excluding co-infection of RV-A and NV GII) at 5.42%, and co-infection of RV-A and NV GII at 1.14%. The highest RV-A ratios were shown in children ≤1 year and 2-5 years. Jining, Jinxiang County, and Liangshan County had notably high RV-A ratios at 24.37% (excluding co-infection of RV-A and NV GII) and 18.33% (excluding co-infection of RV-A and NV GII), respectively. Jining, Qufu, and Weishan had no RV-A positives. Weishan showed the highest NV GII ratios at 35.48% (excluding co-infection of RV-A and NV GII). Genotype analysis showed that, in 2021, G9P[8] and G2P[4] were dominant at 94.44% and 5.56%, respectively. In 2022, G8P[8], G9P[8], and G1P[8] were prominent at 75.86%, 13.79%, and 10.35%, respectively. In 2021, GII.3[P12], GII.4[P16], and GII.4[P31] constituted 71.42%, 14.29%, and 14.29%, respectively. In 2022, GII.3[P12] and GII.4[P16] accounted for 55.00% and 45.00%, respectively. RV-A and NV showed varying patterns for different time frames, age groups, and regions within Jining. Genotypic shifts were also observed in prevalent RV-A and NV GII strains in Jining City from 2021 to 2022. Ongoing monitoring of RV-A and NV is recommended for effective prevention and control.

Phylogenetic Analyses of Rotavirus A, B and C Detected on a Porcine Farm in South Africa.

Rotaviruses (RVs) are known to infect various avian and mammalian hosts, including swine. The most common RVs associated with infection in pigs are A, B, C and H (RVA-C; RVH). In this study we analysed rotavirus strains circulating on a porcine farm in the Western Cape province of South Africa over a two-year period. Whole genomes were determined by sequencing using Illumina MiSeq without prior genome amplification. Fifteen RVA genomes, one RVB genome and a partial RVC genome were identified. Phylogenetic analyses of the RVA data suggested circulation of one dominant strain (G5-P[6]/P[13]/P[23]-I5-R1-C1-M1-A8-N1-T7-E1-H1), typical of South African porcine strains, although not closely related to previously detected South African porcine strains. Reassortment with three VP4-encoding P genotypes was detected. The study also reports the first complete RVB genome (G14-P[5]-I13-R4-C4-M4-A10-T4-E4-H7) from Africa. The partial RVC (G6-P[5]-IX-R1-C1-MX-A9-N6-T6-EX-H7) strain also grouped with porcine strains. The study shows the continued circulation of an RVA strain, with a high reassortment rate of the VP4-encoding segment, on the porcine farm. Furthermore, incidents of RVB and RVC on this farm emphasize the complex epidemiology of rotavirus in pigs.

Human Rotaviruses of Multiple Genotypes Acquire Conserved VP4 Mutations during Serial Passage.

Human rotaviruses exhibit limited tropism and replicate poorly in most cell lines. Attachment protein VP4 is a key rotavirus tropism determinant. Previous studies in which human rotaviruses were adapted to cultured cells identified mutations in VP4. However, most such studies were conducted using only a single human rotavirus genotype. In the current study, we serially passaged 50 human rotavirus clinical specimens representing five of the genotypes most frequently associated with severe human disease, each in triplicate, three to five times in primary monkey kidney cells then ten times in the MA104 monkey kidney cell line. From 13 of the 50 specimens, we obtained 25 rotavirus antigen-positive lineages representing all five genotypes, which tended to replicate more efficiently in MA104 cells at late versus early passage. We used Illumina next-generation sequencing and analysis to identify variants that arose during passage. In VP4, variants encoded 28 mutations that were conserved for all P[8] rotaviruses and 12 mutations that were conserved for all five genotypes. These findings suggest there may be a conserved mechanism of human rotavirus adaptation to MA104 cells. In the future, such a conserved adaptation mechanism could be exploited to study human rotavirus biology or efficiently manufacture vaccines.

Whole-genome analysis of human group A rotaviruses in 1980s Japan and evolutionary assessment of global Wa-like strains across half a century.

Historically, the Wa-like strains of human group A rotavirus (RVA) have been major causes of gastroenteritis. However, since the 2010s, the circulation of non-Wa-like strains has been increasingly reported, indicating a shift in the molecular epidemiology of RVA. Although understanding RVA evolution requires the analysis of both current and historical strains, comprehensive pre-1980's sequencing data are scarce globally. We determined the whole-genome sequences of representative strains from six RVA gastroenteritis outbreaks observed at an infant home in Sapporo, Japan, between 1981 and 1989. These outbreaks were mainly caused by G1 or G3 Wa-like strains, resembling strains from the United States in the 1970s-1980s and from Malawi in the 1990s. Phylogenetic analysis of these infant home strains, together with Wa-like strains collected worldwide from the 1970s to 2020, revealed a notable trend: pre-2010 strains diverged into multiple lineages in many genomic segments, whereas post-2010 strains tended to converge into a single lineage. However, Bayesian skyline plot indicated near-constant effective population sizes from the 1970s to 2020, and selection pressure analysis identified positive selection only at amino acid 75 of NSP2. These results suggest that evidence supporting the influence of rotavirus vaccines, introduced globally since 2006, on Wa-like RVA molecular evolution is lacking at present, and phylogenetic analysis may simply reflect natural fluctuations in RVA molecular evolution. Evaluating the long-term impact of RV vaccines on the molecular evolution of RVA requires sustained surveillance.

Molecular characterization of rotavirus indicates predominance of G9P[4] genotype among children with acute gastroenteritis: First report after vaccine introduction in Pakistan.

Globally, Group A rotavirus (RVA) is the leading cause of acute gastroenteritis in children under 5 years old, with Pakistan having the highest rates of RVA-related morbidity and mortality. The current study aims to determine the genetic diversity of rotavirus and evaluate the impact of Rotarix-vaccine introduction on disease epidemiology in Pakistan. A total of 4749 children, hospitalized with acute gastroenteritis between 2018 and 2020, were tested at four hospitals in Lahore and Karachi. Of the total, 19.3% (918/4749) cases were tested positive for RVA antigen, with the positivity rate varying annually (2018 = 22.7%, 2019 = 14.4%, 2020 = 20.9%). Among RVA-positive children, 66.3% were under 1 year of age. Genotyping of 662 enzyme-linked immuno sorbent assay-positive samples revealed the predominant genotype as G9P[4] (21.4%), followed by G1P[8] (18.9%), G3P[8] (11.4%), G12P[6] (8.7%), G2P[4] (5.7%), G2P[6] (4.8%), and 10.8% had mixed genotypes. Among vaccinated children, genotypes G9P[4] and G12P[6] were more frequently detected, whereas a decline in G2P[4] was observed. Phylogenetic analysis confirmed the continued circulation of indigenous genotypes detected earlier in the country except G9 and P[6] strains. Our findings highlight the predominance of G9P[4] genotype after the vaccine introduction thus emphasizing continual surveillance to monitor the disease burden, viral diversity, and their impact on control of rotavirus gastroenteritis in children.

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.

Tris stabilized AuNPs based lateral flow immunochromatography for the simultaneous detection of porcine epidemic diarrhea virus and rotavirus on-site.

Porcine epidemic diarrhea virus (PEDV) and rotavirus has posed a significant threat to the pig industry annually across different nations, resulting in huge economic losses. The frequent co-infection of these two viruses in clinical settings complicates the process of differential diagnoses. Rapid and accurate detection of PEDV and rotavirus is in great demand for timely diarrhea disease prevention and control. In this study, tris stabilized AuNPs were prepared and a sensitive lateral flow immunoassay (LFIA) sensor was developed for the simultaneous and rapid detection of PEDV and rotavirus on site. After the system optimization, the established LFIA can simultaneously identify PEDV and rotavirus with limits of detection (LOD) of 1.25 × 103 TCID50 mL-1 and 3.13 × 102 pg mL-1, respectively. When applying for clinical samples, the LFIA show a concordance of 95 % and 100 % to reverse transcript polymerase chain reaction (RT-PCR) for PEDV and rotavirus respectively. Therefore, this LFIA can qualitatively detect PEDV and rotavirus in 18 min with high sensitivity and accuracy without any sophisticated equipment and operation, making it a promising candidate for the early diagnosis of PEDV or/and rotavirus diarrhea on site.

Update on Early-Life T Cells: Impact on Oral Rotavirus Vaccines.

Rotavirus infection continues to be a significant public health problem in developing countries, despite the availability of several vaccines. The efficacy of oral rotavirus vaccines in young children may be affected by significant immunological differences between individuals in early life and adults. Therefore, understanding the dynamics of early-life systemic and mucosal immune responses and the factors that affect them is essential to improve the current rotavirus vaccines and develop the next generation of mucosal vaccines. This review focuses on the advances in T-cell development during early life in mice and humans, discussing how immune homeostasis and response to pathogens is established in this period compared to adults. Finally, the review explores how this knowledge of early-life T-cell immunity could be utilized to enhance current and novel rotavirus vaccines.

Australian Rotavirus Surveillance Program Annual Report, 2022.

Abstract: This report from the Australian Rotavirus Surveillance Program describes the circulating rotavirus genotypes identified in children and adults during the period 1 January to 31 December 2022. After two years of a lower number of stool samples received as a result of the coronavirus disease 2019 (COVID-19) pandemic, this reporting period saw the highest number of samples received since the 2017 surveillance period, with samples received from all states and territories. During this period, 1,379 faecal specimens had been referred for rotavirus G- and P- genotype analysis, of which 1,276 were confirmed as rotavirus positive. In total, 1,119/1,276 were identified as wildtype rotavirus, 155/1,276 identified as the Rotarix vaccine strain and 2/1,276 that could not be confirmed as vaccine or wildtype due to sequencing failure. Whilst G12P[8] was the dominant genotype nationally among wildtype samples (28.2%; 315/1,119), multiple genotypes were identified at similar frequencies including G9P[4] (22.3%; 249/1,119) and G2P[4] (20.3%; 227/1,119). Geographical differences in genotype distribution were observed, largely driven by outbreaks reported in some jurisdictions. Outbreaks and increased reports of rotavirus disease were reported in the Northern Territory, Queensland, and New South Wales. A small number of unusual genotypes, potentially zoonotic in nature, were identified, including: G8P[14]; G10[14]; caninelike G3P[3]; G6P[9]; and G11P[25]. Ongoing rotavirus surveillance is crucial to identify changes in genotypic patterns and to provide diagnostic laboratories with quality assurance by reporting incidences of wildtype, vaccine-like, or false positive rotavirus results.

Enteric viral pathogens and child growth among under-five children: findings from South Asia and sub-Saharan Africa.

Enteric viral pathogens are associated with a significant burden of childhood morbidity and mortality. We investigated the relationship between viral pathogens and child growth among under-5 children. We analyzed data from 5572/22,567 children enrolled in the Global Enteric Multicenter Study across seven study sites (2007-2011). Multiple linear regression was used to examine the association between the viral pathogens and changes of length/height-for-age (HAZ), weight-for-age (WAZ), and weight-for-length/height (WHZ) z-scores, stratified by diarrheal symptoms and adjusted for potential covariates. Rotavirus (18.51%) and norovirus (7.33%) were the most prevalent enteric viral pathogens among symptomatic and asymptomatic under-5 children, respectively. Infection with individual enteric viral pathogens hurts child growth in asymptomatic children. However, the relationship with HAZ was less clear and statistically non-significant. On the other hand, the combined viral pathogens demonstrated a strong negative influence on child growth [WAZ: ß coef.: - 0.10 (95%, CI - 0.15, - 0.05); P < 0.001 and WHZ: ß: - 0.12 (95% CI - 0.17, - 0.07); P < 0.001] among asymptomatic children. Infection with any viral pathogen was associated with growth shortfalls [HAZ: ß: - 0.05 (95% CI - 0.09, 0.00); P = 0.03 and WAZ: ß: - 0.11 (95% CI - 0.16, - 0.07); P < 0.001 and WHZ: ß: - 0.13 (95% CI - 0.18, - 0.09); P < 0.001], though the relationship with HAZ was less evident and became statistically non-significant in older children. Notably, among symptomatic children with moderate-to-severe diarrhea, individual enteric viral pathogens, as well as the combined effects of these pathogens [WHZ: ß: 0.07; (95% CI 0.01, 0.14); P = 0.03] and the presence of any virus [HAZ: ß: 0.09 (95% CI 0.05, 0.13) & WAZ: ß: 0.08 (95% CI 0.03, 0.12); P < 0.001], exhibited positive effects on child growth. While previous studies hypothesized that several viral pathogens had a conflicting controversial role in child growth, we find clear indications that enteric viral pathogens are associated with growth shortfalls, specifically among asymptomatic children. These findings highlight the need for preventive strategies targeting children with enteric viral pathogens, which could address the consequences of growth faltering.

Comprehensive genetic analysis of the first near-complete genome of bovine coronavirus and partial genome of bovine rotavirus in Türkiye through metagenomics.

Obtaining the complete or near-complete genome sequence of pathogens is becoming increasingly crucial for epidemiology, virology, clinical science and practice. This study aimed to detect viruses and conduct genetic characterization of genomes using metagenomics in order to identify the viral agents responsible for a calf's diarrhoea. The findings showed that bovine coronavirus (BCoV) and bovine rotavirus (BRV) are the primary viral agents responsible for the calf's diarrhoea. The current study successfully obtained the first-ever near-complete genome sequence of a bovine coronavirus (BCoV) from Türkiye. The G+C content was 36.31% and the genetic analysis revealed that the Turkish BCoV strain is closely related to respiratory BCoV strains from France and Ireland, with high nucleotide sequence and amino acid identity and similarity. In the present study, analysis of the S protein of the Turkish BCoV strain revealed the presence of 13 amino acid insertions, one of which was found to be shared with the French respiratory BCoV. The study also identified a BRV strain through metagenomic analysis and detected multiple mutations within the structural and non-structural proteins of the BRV strain, suggesting that the BRV Kirikkale strain may serve as an ancestor for reassortants with interspecies transmission, especially involving rotaviruses that infect rabbits and giraffes.

Major changes in prevalence and genotypes of rotavirus diarrhea in Beijing, China after RV5 rotavirus vaccine introduction.

To analyze the epidemiological characteristics of group A rotavirus (RVA) diarrhea in Beijing between 2019 and 2022 and evaluate the effectiveness of the RV5 vaccine. Stool specimens were collected from patients with acute diarrhea, and RVA was detected and genotyped. The whole genome of RVA was sequenced by fragment amplification and Sanger sequencing. Phylogenetic trees were constructed using Bayesian and maximum likelihood methods. Descriptive epidemiological methods were used to analyze the characteristics of RVA diarrhea. Test-negative design was used to evaluate the vaccine effectiveness (VE) of the RV5. Compared with 2011-2018, RVA-positive rates in patients with acute diarrhea under 5 years of age and adults decreased significantly between 2019 and 2022, to 9.45% (249/634) and 3.66% (220/6016), respectively. The predominant genotype of RVA had changed from G9-VIP[8]-III between 2019 and 2021 to G8-VP[8]-III in 2022, and P[8] sequences from G8-VP[8]-III strains formed a new branch called P[8]-IIIb. The complete genotype of G8-VP[8]-III was G8-P[8]-I2-R2-C2-M2-A2-N2-T2-E2-H2. The VE of 3 doses of RV5 was 90.4% (95% CI: 28.8%-98.7%) against RVA diarrhea. The prevalence of RVA decreased in Beijing between 2019 and 2022, and the predominant genotype changed to G8P[8], which may be related to RV5 vaccination. Continuous surveillance is necessary to evaluate vaccine effectiveness and improve vaccine design.

Reverse Genetics of Murine Rotavirus: A Comparative Analysis of the Wild-Type and Cell-Culture-Adapted Murine Rotavirus VP4 in Replication and Virulence in Neonatal Mice.

Small-animal models and reverse genetics systems are powerful tools for investigating the molecular mechanisms underlying viral replication, virulence, and interaction with the host immune response in vivo. Rotavirus (RV) causes acute gastroenteritis in many young animals and infants worldwide. Murine RV replicates efficiently in the intestines of inoculated suckling pups, causing diarrhea, and spreads efficiently to uninoculated littermates. Because RVs derived from human and other non-mouse animal species do not replicate efficiently in mice, murine RVs are uniquely useful in probing the viral and host determinants of efficient replication and pathogenesis in a species-matched mouse model. Previously, we established an optimized reverse genetics protocol for RV and successfully generated a murine-like RV rD6/2-2g strain that replicates well in both cultured cell lines and in the intestines of inoculated pups. However, rD6/2-2g possesses three out of eleven gene segments derived from simian RV strains, and these three heterologous segments may attenuate viral pathogenicity in vivo. Here, we rescued the first recombinant RV with all 11 gene segments of murine RV origin. Using this virus as a genetic background, we generated a panel of recombinant murine RVs with either N-terminal VP8* or C-terminal VP5* regions chimerized between a cell-culture-adapted murine ETD strain and a non-tissue-culture-adapted murine EW strain and compared the diarrhea rate and fecal RV shedding in pups. The recombinant viruses with VP5* domains derived from the murine EW strain showed slightly more fecal shedding than those with VP5* domains from the ETD strain. The newly characterized full-genome murine RV will be a useful tool for dissecting virus-host interactions and for studying the mechanism of pathogenesis in neonatal mice.

Histo-Blood Group Antigen-Producing Bacterial Cocktail Reduces Rotavirus A, B, and C Infection and Disease in Gnotobiotic Piglets.

The suboptimal performance of rotavirus (RV) vaccines in developing countries and in animals necessitates further research on the development of novel therapeutics and control strategies. To initiate infection, RV interacts with cell-surface O-glycans, including histo-blood group antigens (HBGAs). We have previously demonstrated that certain non-pathogenic bacteria express HBGA- like substances (HBGA+) capable of binding RV particles in vitro. We hypothesized that HBGA+ bacteria can bind RV particles in the gut lumen protecting against RV species A (RVA), B (RVB), and C (RVC) infection in vivo. In this study, germ-free piglets were colonized with HBGA+ or HBGA- bacterial cocktail and infected with RVA/RVB/RVC of different genotypes. Diarrhea severity, virus shedding, immunoglobulin A (IgA) Ab titers, and cytokine levels were evaluated. Overall, colonization with HBGA+ bacteria resulted in reduced diarrhea severity and virus shedding compared to the HBGA- bacteria. Consistent with our hypothesis, the reduced severity of RV disease and infection was not associated with significant alterations in immune responses. Additionally, colonization with HBGA+ bacteria conferred beneficial effects irrespective of the piglet HBGA phenotype. These findings are the first experimental evidence that probiotic performance in vivo can be improved by including HBGA+ bacteria, providing decoy epitopes for broader/more consistent protection against diverse RVs.

The Role of the Host Cytoskeleton in the Formation and Dynamics of Rotavirus Viroplasms.

Rotavirus (RV) replicates within viroplasms, membraneless electron-dense globular cytosolic inclusions with liquid-liquid phase properties. In these structures occur the virus transcription, replication, and packaging of the virus genome in newly assembled double-layered particles. The viroplasms are composed of virus proteins (NSP2, NSP5, NSP4, VP1, VP2, VP3, and VP6), single- and double-stranded virus RNAs, and host components such as microtubules, perilipin-1, and chaperonins. The formation, coalescence, maintenance, and perinuclear localization of viroplasms rely on their association with the cytoskeleton. A stabilized microtubule network involving microtubules and kinesin Eg5 and dynein molecular motors is associated with NSP5, NSP2, and VP2, facilitating dynamic processes such as viroplasm coalescence and perinuclear localization. Key post-translation modifications, particularly phosphorylation events of RV proteins NSP5 and NSP2, play pivotal roles in orchestrating these interactions. Actin filaments also contribute, triggering the formation of the viroplasms through the association of soluble cytosolic VP4 with actin and the molecular motor myosin. This review explores the evolving understanding of RV replication, emphasizing the host requirements essential for viroplasm formation and highlighting their dynamic interplay within the host cell.

Changes in the epidemiology and clinical characteristics of viral gastroenteritis among hospitalized children in the Mainland of China: a retrospective study from 2016 to 2020.

BACKGROUND: Acute gastroenteritis (AGE) causes significant morbidity in children worldwide; however, the disease burden of children hospitalized with viral gastroenteritis in China has been rarely described. Through this study, we analyzed the data of hospitalized children with viral gastroenteritis to explore the changes in the epidemiology and clinical characteristics of viral gastroenteritis in the mainland of China. METHODS: Data were extracted from Futang Children's Medical Development Research Center (FRCPD), between 2016 and 2020, across 27 hospitals in 7 regions. The demographics, geographic distribution, pathogenic examination results, complications, hospital admission date, length of hospital stays, hospitalization charges and outcomes were collected and analyzed. RESULTS: Viral etiological agents included rotavirus (RV), adenovirus (ADV), norovirus (NV) and coxsackievirus (CV) that were detected in 25,274 (89.6%), 1,047 (3.7%), 441 (1.5%) and 83 (0.3%) cases. There was a higher prevalence of RV and NV infection among children younger than 3 years of age. RV and NV had the highest detection rates in winter, while ADV in summer. Children with viral gastroenteritis were often accompanied by other diseases, such as myocardial diseases (10.98-31.04%), upper respiratory tract diseases (1.20-20.15%), and seizures (2.41-14.51%). Among those cases, the co-infection rate with other pathogens was 6.28%, with Mycoplasma pneumoniae (M. pneumoniae), Epstein-Barr virus (EBV), and influenza virus (FLU) being the most common pathogens. The median length of stay was 5 days, and the median cost of hospitalization corresponded to587 US dollars. CONCLUSIONS: This finding suggests that viral gastroenteritis, especially those caused by RV, is a prevalent illness among younger children. Co-infections and the presence of other diseases are common. The seasonality and regional variation of viral etiological agents highlight the need for targeted prevention and control measures. Although viral gastroenteritis rarely leads to death, it also results in a significant economic burden on healthcare systems.

Prevalence and factors associated with rotavirus diarrhea among children aged 3-24 months after the introduction of the vaccine at a referral hospital in Uganda: a cross-sectional study.

BACKGROUND: Rotavirus has a significant morbidity and mortality in children under two years. The burden of rotavirus diarrhea 4 years post introduction of rotavirus vaccine in Uganda is not well established. This study aimed to determine the prevalence, severity of dehydration and factors associated with rotavirus diarrhea among children aged 3 to 24 months after the introduction of the vaccine at Fort Portal Regional Referral hospital. METHODS: This was a cross-sectional hospital-based study in which children with acute watery diarrhea were included. A rectal tube was used to collect a stool sample for those unable to provide samples. Stool was tested for rotavirus using rapid immunochromatographic assay. Data was analysed using SPSS version 22 with logistic regression done to determine the factors. RESULTS: Out of 268 children with acute watery diarrhea, 133 (49.6%) were females. Rotavirus test was positive in 42 (15.7%), majority of whom had some dehydration 28(66.7%). The factors that were independently associated with rotavirus diarrhea were; age < 12 months (AOR = 8.87, P = 0.014), male gender (AOR = 0.08, P = 0.001), coming from a home with another person with diarrhea (AOR = 17.82, P = 0.001) or a home where the water source was a well (AOR = 50.17, P = 0.002). CONCLUSION: The prevalence of rotavirus diarrhea was three times less in the post rotavirus vaccination period compared to pre-rota vaccination period. Majority of the participants with rotavirus diarrhea had some dehydration. There is need for provision of safe water sources to all homes. Surveillance to determine the cause of the non rota diarrhea should be done.

Health economic evaluation of 2-dose and 3-dose rotavirus vaccines in children below 5 years of age in Morocco.

Following the introduction of rotavirus vaccination into the Moroccan National Immunization Program, the prevalence of the disease has decreased by nearly 50%. However, evidence on the economic value of rotavirus vaccinations in Morocco is limited. This health economic analysis evaluated, from both country payer and societal perspectives, the costs and the cost-effectiveness of three rotavirus vaccines using a static, deterministic, population model in children aged < 5 years in Morocco. Included vaccines were HRV (2-dose schedule), HBRV (3-dose schedule) and BRV-PV 1-dose vial (3-dose schedule). One-way and probabilistic sensitivity analyses were conducted to assess the impact of uncertainty in model inputs. The model predicted that vaccination with HRV was estimated to result in fewer rotavirus gastroenteritis events (-194 homecare events, -57 medical visits, -8 hospitalizations) versus the 3-dose vaccines, translating into 7 discounted quality-adjusted life years gained over the model time horizon. HRV was associated with lower costs versus HBRV from both the country payer (-$1.8 M) and societal (-$4.1 M) perspectives, and versus BRV-PV 1-dose vial from the societal perspective (-$187,000), dominating those options in the cost-effectiveness analysis. However, costs of BRV-PV 1-dose vial were lower than HRV from the payer perspective, resulting in an ICER of approximately $328,376 per QALY, above the assumed cost effectiveness threshold of $3,500. Vaccination with a 2-dose schedule of HRV may be a cost-saving option and could lead to better health outcomes for children in Morocco versus 3-dose schedule rotavirus vaccines.