Global Estimates of Rotavirus Hospitalizations Among Children Below 5 Years in 2019 and Current and Projected Impacts of Rotavirus Vaccination

TRIM29 controls enteric RNA virus-induced intestinal inflammation by targeting NLRP6 and NLRP9b signaling pathways

Infections by enteric virus and intestinal inflammation are recognized as a leading cause of deadly gastroenteritis, and NLRP6 and NLRP9b signaling control these infection and inflammation. However, the regulatory mechanisms of the NLRP6 and NLRP9b signaling in enteric viral infection remain unexplored. In this study, we found that the E3 ligase TRIM29 suppressed type III interferon (IFN-λ) and interleukin-18 (IL-18) production by intestinal epithelial cells (IECs) when exposed to polyinosinic:polycytidylic acid (poly I:C) and enteric RNA viruses. Knockout of TRIM29 in IECs was efficient to restrict intestinal inflammation triggered by the enteric RNA viruses, rotavirus in suckling mice, and the encephalomyocarditis virus (EMCV) in adults. This attenuation in inflammation was attributed to the increased production of IFN-λ and IL-18 in the IECs and more recruitment of intraepithelial protective Ly6A+CCR9+CD4+ T cells in small intestines from TRIM29-deficient mice. Mechanistically, TRIM29 promoted K48-linked ubiquitination, leading to the degradation of NLRP6 and NLRP9b, resulting in decreased IFN-λ and IL-18 secretion by IECs. Our findings reveal that enteric viruses utilize TRIM29 to inhibit IFN-λ and inflammasome activation in IECs, thereby facilitating viral-induced intestinal inflammation. This indicates that targeting TRIM29 could offer a promising therapeutic strategy for alleviating gut diseases.

Viral diarrheas - newer advances in diagnosis and management

PURPOSE OF REVIEW

Viruses are the most common etiological agents of diarrhea in children. Despite rotavirus vaccine introduction, rotavirus remains as the leading cause of death globally, followed by norovirus, which represents a diagnostic challenge. Here, we describe new advances in the diagnosis and management of viral diarrheas.

RECENT FINDINGS

Although immunoassays are widely used for their fast turnaround time and low cost, molecular techniques have become the most reliable diagnostic method due to their high sensitivity and capacity to analyze multiple pathogens in gastrointestinal panels. Isothermal nucleic acid amplification assays (LAMP and RPA) are promising techniques since they do not require sophisticated equipment and can be used as point-of-care testing. CRISPR/Cas nucleic acid detection systems are new diagnostic methods with great potential. Several recent published articles describe the role of human intestinal enteroids to characterize norovirus infection, to test new drugs, and for vaccine development. The interaction between the human gut microbiota and gastrointestinal viral infections has been extensively reviewed and offers some innovative mechanisms for therapeutic and preventive measures.

SUMMARY

Although important advances have been made, more research is needed to address remaining challenges and further improve diagnostic capabilities and better management strategies for this critical infectious disease.

Multiple-component interventions to increase rotavirus vaccine uptake in children: a randomised controlled trial

Background

Rotavirus vaccine has not been included in the Hong Kong Government's Childhood Immunisation Programme. This randomised controlled trial examined whether a simple intervention package can increase rotavirus vaccine uptake in Hong Kong children.

Methods

Postpartum mothers were recruited from two public hospitals in Hong Kong and randomly allocated into three groups using block randomisation, with block sizes kept unknown to investigators and research staff. Control-subjects received public rotavirus information. Subjects in intervention group 1 additionally received: key rotavirus information with a hyperlink to a webpage showing private clinics providing rotavirus vaccines and guidance on searching the clinics, and vaccination reminders. Subjects in intervention group 2 received the same intervention as group 1, plus tokens to receive free rotavirus vaccines at specific health centres. Rotavirus vaccination status was collected when children were approximately 8 months old. Maternal attitudes towards rotavirus vaccine were assessed at enrolment and at the end of the study. This trial has been registered in the Chinese Clinical Trial Register (Ref.:ChiCTR2000039791).

Findings

From 16 February to 30 July 2021, 788 eligible mothers were recruited and randomly allocated to control group (n = 263), intervention group 1 (n = 263), and intervention group 2 (n = 262). The full intervention package (intervention group 2 relative to control group) increased rotavirus vaccine uptake by 1.7 times (95% confidence interval [CI] = 1.49-1.97) or by 33 percent-points (from 48% to 81% uptake). Provision of key rotavirus information with vaccination reminders (intervention group 1 relative to control group) and removal of financial barrier (intervention group 2 relative to intervention group 1) increased uptake by 1.17 times (95% CI = 0.99-1.38) or 8 percent-points, and by 1.46 times (95% CI = 1.29-1.66) or 25 percent-points, respectively.

Interpretation

A multiple-component intervention package, and in particular providing free vaccine, could increase the uptake of rotavirus vaccine in Hong Kong children. The impact of the intervention package was greatest in low-income families, emphasising the importance of removing financial barriers to vaccination to promote equity. Incorporating rotavirus vaccine into the routine CIP could further protect more young children from rotavirus infection and improve equity.

Funding

This work was supported by the Health and Medical Research Fund by the Health Bureau, Government of Hong Kong SAR [Ref.: 19180202].

Molecular evolutionary analysis of novel NSP4 mono-reassortant G1P[8]-E2 rotavirus strains that caused a discontinuous epidemic in Japan in 2015 and 2018

In the 2010s, several unusual rotavirus strains emerged, causing epidemics worldwide. This study reports a comprehensive molecular epidemiological study of rotaviruses in Japan based on full-genome analysis. From 2014 to 2019, a total of 489 rotavirus-positive stool specimens were identified, and the associated viral genomes were analyzed by next-generation sequencing. The genotype constellations of those strains were classified into nine patterns (G1P[8] (Wa), G1P[8]-E2, G1P[8] (DS-1), G2P[4] (DS-1), G3P[8] (Wa), G3P[8] (DS-1), G8P[8] (DS-1), G9P[8] (Wa), and G9P[8]-E2). The major prevalent genotype differed by year, comprising G8P[8] (DS-1) (37% of that year's isolates) in 2014, G1P[8] (DS-1) (65%) in 2015, G9P[8] (Wa) (72%) in 2016, G3P[8] (DS-1) (66%) in 2017, G1P[8]-E2 (53%) in 2018, and G9P[8] (Wa) (26%) in 2019. The G1P[8]-E2 strains (G1-P[8]-I1-R1-C1-M1-A1-N1-T1-E2-H1) isolated from a total of 42 specimens in discontinuous years (2015 and 2018), which were the newly-emerged NSP4 mono-reassortant strains. Based on the results of the Bayesian evolutionary analyses, G1P[8]-E2 and G9P[8]-E2 were hypothesized to have been generated from distinct independent inter-genogroup reassortment events. The G1 strains detected in this study were classified into multiple clusters, depending on the year of detection. A comparison of the predicted amino acid sequences of the VP7 epitopes revealed that the G1 strains detected in different years encoded VP7 epitopes harboring distinct mutations. These mutations may be responsible for immune escape and annual changes in the prevalent strains.

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.

Epidemiology of Rotavirus in Humans, Animals, and the Environment in Africa: A Systematic Review and Meta-analysis

BACKGROUND

Globally, rotavirus infections are the most common cause of diarrhea-related deaths, especially among children under 5 years of age. This virus can be transmitted through the fecal-oral route, although zoonotic and environmental contributions to transmission are poorly defined. The purpose of this study is to determine the epidemiology of rotavirus in humans, animals, and the environment in Africa, as well as the impact of vaccination.

METHODS

We searched PubMed, Web of Science, Africa Index Medicus, and African Journal Online, identifying 240 prevalence data points from 224 articles between 2009 and 2022.

RESULTS

Human rotavirus prevalence among patients with gastroenteritis was 29.8% (95% confidence interval [CI], 28.1%-31.5%; 238 710 participants), with similar estimates in children under 5 years of age, and an estimated case fatality rate of 1.2% (95% CI, .7%-2.0%; 10 440 participants). Prevalence was estimated to be 15.4% and 6.1% in patients with nongastroenteritis illnesses and apparently healthy individuals, respectively. Among animals, prevalence was 9.3% (95% CI, 5.7%-13.7%; 6115 animals), and in the environmental water sources, prevalence was 31.4% (95% CI, 17.7%-46.9%; 2530 samples).

DISCUSSION

Our findings highlight the significant burden of rotavirus infection in Africa, and underscore the need for a One Health approach to limiting the spread of this disease.

Clinical factors predicting rotavirus diarrhea in children: A cross-sectional study from two hospitals

BACKGROUND

Rotavirus is still a significant contributing morbidity and mortality in pediatric patients.

AIM

To look at clinical signs and symptoms and laboratory findings that can predict rotavirus gastroenteritis compared to non-rotavirus gastroenteritis.

METHODS

This was a cross-sectional study with medical records obtained from December 2015 to December 2019. Inclusion criteria for this study include all hospitalised pediatric patients (0-18 years old) diagnosed with suspected rotavirus diarrhea. The receiver operating curve and Hosmer-Lemeshow test would be used to assess the final prediction findings' calibration (goodness of fit) and discrimination performance.

RESULTS

This study included 267 participants with 187 (70%) rotavirus-diarrhea cases. The patients were primarily male in both rotavirus (65.2%) and non-rotavirus (62.5%) groups. The median age is 1.33 years old (0.08-17.67 years old). Multivariate analysis shows that wet season (ORadj = 2.5; 95%CI: 1.3-4.8, Padj = 0.006), length of stay (LOS) ≥ 3 days (ORadj = 5.1; 95%CI: 1.4-4.8, Padj = 0.015), presence of abdominal pain (ORadj = 3.0; 95%CI: 1.3-6.8, Padj = 0.007), severe dehydration (ORadj = 2.9; 95%CI: 1.1-7.9, Padj = 0.034), abnormal white blood cell counts (ORadj = 2.8; 95%CI: 1.3-6.0, Padj = 0.006), abnormal random blood glucose (ORadj = 2.3; 95%CI: 1.2-4.4, Padj = 0.018) and presence of fecal leukocytes (ORadj = 4.1, 95%CI: 1.7-9.5, Padj = 0.001) are predictors of rotavirus diarrhea. The area under the curve for this model is 0.819 (95%CI: 0.746-0.878, P value < 0.001), which shows that this model has good discrimination.

CONCLUSION

Wet season, LOS ≥ 3 d, presence of abdominal pain, severe dehydration, abnormal white blood cell counts, abnormal random blood glucose, and presence of fecal leukocytes predict rotavirus diarrhea.

Characterization of Rotavirus Strains Responsible for Breakthrough Diarrheal Diseases among Zambian Children Using Whole Genome Sequencing

The occurrence of rotavirus (RV) infection among vaccinated children in high-burden settings poses a threat to further disease burden reduction. Genetically altered viruses have the potential to evade both natural infection and vaccine-induced immune responses, leading to diarrheal diseases among vaccinated children. Studies characterizing RV strains responsible for breakthrough infections in resource-limited countries where RV-associated diarrheal diseases are endemic are limited. We aimed to characterize RV strains detected in fully vaccinated children residing in Zambia using next-generation sequencing. We conducted whole genome sequencing on Illumina MiSeq. Whole genome assembly was performed using Geneious Prime 2023.1.2. A total of 76 diarrheal stool specimens were screened for RV, and 4/76 (5.2%) were RV-positive. Whole genome analysis revealed RVA/Human-wt/ZMB/CIDRZ-RV2088/2020/G1P[4]-I2-R2-C2-M2-A2-N2-T2-E2-H2 and RVA/Human-wt/ZMB/CIDRZ-RV2106/2020/G12P[4]-I1-R2-C2-M2-A2-N1-T2-E1-H2 strains were mono and multiple reassortant (exchanged genes in bold) respectively, whilst RVA/Human-wt/ZMB/CIDRZ-RV2150/2020/G12P[8]-I1-R1-C1-M1-A1-N1-T1-E1-H1 was a typical Wa-like strain. Comparison of VP7 and VP4 antigenic epitope of breakthrough strains and Rotarix strain revealed several amino acid differences. Variations in amino acids in antigenic epitope suggested they played a role in immune evasion of neutralizing antibodies elicited by vaccination. Findings from this study have the potential to inform national RV vaccination strategies and the design of highly efficacious universal RV vaccines.

[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.

Rotavirus vaccination as a public health strategy to reduce the burden of hospitalization: The field experience of Italy (2008-2018)

Rotavirus (RV) infection is a leading cause of severe diarrhea among children younger than 5 years old and a considerable cause of RV gastroenteritis (RVGE) hospitalization. This study aimed to evaluate the impact of vaccination in Italy in the reduction of the burden of RV-related disease, estimating the relation between vaccination coverage and hospitalization rates. RVGE-related hospitalizations that occurred in Italy from 2008 to 2018 among children aged 0-35 months were assessed by consulting the Hospital Discharge Record database and including records whose ICD-9-CM diagnosis code was 008.61 in the first or in any diagnosis position. In the 2008-2018 period, a total of 17 535 791 at-risk person-years were considered and 74 211 (423.2 cases × 100 000 per year) RVGE hospitalizations were observed. Higher hospitalization rates occurred in males (456.6 vs. 387.9 × 100 000 per year) and in children aged 1 year (507.8 × 100 000 per year). Poisson regression analysis showed a decrease of -1.25% in hospitalization rates (-1.19% to -1.31%, p < 0.001) per unit increase in vaccination coverage. This is the first study that correlates hospitalization rate reduction with a percentage increase in vaccination coverage. Our findings strongly support RV vaccination as an effective public health strategy for reducing RVGE-related hospitalizations.

Detection and full-genotype determination of rare and reassortant rotavirus A strains in Nizhny Novgorod in the European part of Russia

Reassortant DS-1-like rotavirus A strains have been shown to circulate widely in many countries around the world. In Russia, the prevalence of such strains remains unclear due to the preferred use of the traditional binary classification system. In this work, we obtained partial sequence data from all 11 genome segments and determined the full-genotype constellations of rare and reassortant rotaviruses circulating in Nizhny Novgorod in 2016-2019. DS-1-like G3P[8] and G8P[8] strains were found, reflecting the global trend. Most likely, these strains were introduced into the territory of Russia from other countries but subsequently underwent further evolutionary changes locally. G3P[8], G9P[8], and G12P[8] Wa-like strains of subgenotypic lineages that are unusual for the territory of Russia were also identified. Reassortant G2P[8], G4P[4], and G9P[4] strains with one Wa-like gene (VP4 or VP7) on a DS-1-like backbone were found, and these apparently had a local origin. Feline-like G3P[9] and G6P[9] strains were found to be phylogenetically close to BA222 isolated from a cat in Italy but carried some traces of reassortment with human strains from Russia and other countries. Thus, full-genotype determination of rotavirus A strains in Nizhny Novgorod has clarified some questions related to their origin and evolution.

14th International dsRNA Virus Symposium, Banff, Alberta, Canada, 10-14 October 2022

This triennial International dsRNA Virus Symposium covered original data which have accrued during the most recent five years. In detail, the genomic diversity of these viruses continued to be explored; various structure-function studies were carried out using reverse genetics and biophysical techniques; intestinal organoids proved to be very suitable for special pathogenesis studies; and the potential of next generation rotavirus vaccines including use of rotavirus recombinants as vectored vaccine candidates was explored. 'Non-lytic release of enteric viruses in cloaked vesicles' was the topic of the keynote lecture by Nihal Altan-Bonnet, NIH, Bethesda, USA. The Jean Cohen lecturer of this meeting was Polly Roy, London School of Hygiene and Tropical Medicine, who spoke on aspects of the replication cycle of bluetongue viruses, and how some of the data are similar to details of rotavirus replication.

Biolayer Interferometry Analysis for a Higher Throughput Quantification of In-Process Samples of a Rotavirus Vaccine

Rotavirus A infection is a global leading cause of severe acute gastroenteritis associated with life-threatening diarrheal episodes in infants and young children. The disease burden is being reduced, namely due to a wider access to rotavirus vaccines. However, there is a demand to expand rotavirus vaccination programs, and to achieve this, it is critical to improve high-throughput in-process product quality control and vaccine manufacturing monitoring. Here, we present the development of an analytical method for the quantification of rotavirus particles contained in a licensed vaccine. The binding of rotavirus proteins to distinct glycoconjugate receptors and monoclonal antibodies was evaluated using biolayer interferometry analysis, applied on an Octet platform. The antibody strategy presented the best results with a linear response range within 2.5 × 107–1.0 × 108 particles·mL−1 and limits of detection and quantification of 2.5 × 106 and 7.5 × 106 particles·mL−1, respectively. Method suitability for the quantification of in-process samples was shown using samples from different manufacturing stages and their titers were comparable with the approved CCID(50) method. This cell-free method enables a fast and high-throughput analysis, compatible with time constraints during bioprocess development and it is suitable to be adapted to other viral particle-based drug products.