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Background: Globally, rotavirus (RV) A (RVA) is the most common cause of severe and sometimes fatal diarrhea in young children. It is also the major cause of acute gastroenteritis among children in Ethiopia. Currently, the WHO has prequalified four RVA vaccines for universal childhood immunization. Ethiopia introduced the monovalent Rotarix vaccine into its national immunization program in 2013. Since then, only a few studies on the burden and genotype distribution of RVA infection post-vaccine introduction have been conducted (mostly at sentinel surveillance sites). Therefore, this study aimed to assess RVA prevalence and genotype distribution among children under five years in Ethiopia (February 2021–December 2022). Methods: This multi-center hospital-based cross-sectional study involved 537 diarrheic children under-five years old. Rotavirus A detection was conducted using a one-step reverse-transcriptase polymerase chain reaction (RT-PCR). Genotyping was conducted by Sanger sequencing of the VP7 (complete) and VP4 (partial) genes. Descriptive analysis and Pearson's chi-squared test were carried out using SPSS version 29. Phylogenetic analysis with 1000 bootstrap replicates was performed using MEGA version 11 software. Statistical significance was set at p < 0.05 for all analyses. Results: The prevalence of RVA infection among diarrheic children was 17.5%. The most prevalent G-types identified were G3 (37%), the previously uncommon G12 (28%), and G1 (20%). The predominant P-types were P[8] (51%), P[6] (29%), and P[4] (14%). The three major G/P combinations observed were G3P[8] (32.8%), G12P[6] (28.4%), and G1P[8] (19.4%). Phylogenetic analysis revealed clustering of Ethiopian strains with the globally reported strains. Many strains exhibited amino acid differences in the VP4 (VP8* domain) and VP7 proteins compared to vaccine strains, potentially affecting virus neutralization. Conclusions: Despite the high RVA vaccination rate, the prevalence of RVA infection remains significant among diarrheic children in Ethiopia. There is an observable shift in circulating RVA genotypes from G1 to G3, alongside the emergence of unusual G/P genotype combinations such as G9P[4]. Many of these circulating RVA strains have shown amino acid substitutions that may allow for neutralization escape. Therefore, further studies are warranted to comprehend the emergence of these unusual RVA strains and the diverse factors influencing the vaccine's diminished effectiveness in developing countries. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Rotavirus is the leading cause of morbidity and mortality due to acute gastroenteritis among children under five years globally. Early diagnosis of rotavirus infection minimizes its spread and helps to determine the appropriate management of diarrhea. The aim of this study was to evaluate the performance of EpiTuub® Fecal Rotavirus Antigen Rapid Test Kit for the diagnosis of rotavirus infection among diarrheic children under five years in Ethiopian healthcare settings. A total of 537 children with diarrhea were enrolled from three referral hospitals in Amhara National Regional State, Ethiopia. The samples were tested using one-step RT-PCR and EpiTuub® Fecal Rotavirus Antigen Rapid Test Kit (KTR-917, Epitope Diagnostics, San Diego USA) in parallel. Diagnostic performance of the rapid test kit was evaluated using the one-step RT-PCR as a gold standard. The sensitivity, specificity, and predictive values of the rapid test kit were determined. Moreover, the agreement of the rapid test kit with one step RT-PCR was determined by kappa statistics and receiver operators' curve (ROC) analysis was done to assess the overall diagnostic accuracy of the rapid test kit. Fecal Rotavirus Antigen Rapid Test Kit has shown a sensitivity of 75.5% and specificity of 98.2%. The kit was also found to have 89.9% and 95.0% positive and negative predictive values, respectively. The Fecal Rotavirus Antigen Rapid Test Kit has shown a substantial agreement (78.7%, p = 0.0001) with one-step RT-PCR. The overall accuracy of the Fecal Rotavirus Antigen Rapid Test Kit was excellent with the area under the ROC curve of 86.9% (95% CI = 81.6, 92.1%) (p =.0001). Thus, Fecal Rotavirus Antigen Rapid Test is a sensitive, specific, user-friendly, rapid, and equipment-free option to be used at points of care in Ethiopian health care settings where resource is limited precluding the use of one step RT-PCR. Furthermore, the kit could be used in the evaluation and monitoring of rotavirus vaccine effectiveness in the aforementioned settings. [ABSTRACT FROM AUTHOR]