Accuracy and Cross-Reactivity of Rapid Diagnostic Tests for Norovirus and Rotavirus in a Real Clinical Setting

Evaluation of the diagnostic performance of EpiTuub® Fecal Rotavirus Antigen Rapid Test Kit in Amhara National Regional State, Ethiopia: A multi-center cross-sectional study

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.

Assessment of the aetiology of acute gastroenteritis outbreaks in infants reveals rotavirus, noroviruses and adenovirus prevalence and viral coinfections in Nsukka, Nigeria

A better understanding of the aetiology of acute gastroenteritis (AGE) outbreaks in Southeast Nigeria would help safeguarding public health. This study screened stool samples collected from infants (children < 5 years of age) attending selected hospitals in Nsukka for human enteric viruses and evaluated the seasonality of AGE based on three-year records available at selected hospitals. A total of 120 stool samples (109 from diarrhoeal-patients and 11 from non-diarrhoeal patients, as control) collected during the AGE outbreaks of January - March 2019 and January-February 2020. The samples were analysed using an immunochromatographic lateral flow assay for differential qualitative detection of rotavirus (RoV), adenovirus (AdV), and norovirus genogroups I and II (NoVI, NoVII). Three-year (2017-2019) retrospective data on the cases of AGE reported at the hospitals were also collected and analysed. The overall prevalence of acute gastroenteritis was high (75.83%), with 13.19%representing viral co-infections. Rotavirus detection rate (69.17%) was higher than that for other viral agents (15.83%). Both mono- and mixed infections were observed for RoV, AdV and NoVII, whereas NoVI was detected only in co-infection cases. Analysis of risk factors showed that acute gastroenteritis was detected more often in infants of age ˂1 year (73.53%) than in those 1 ≤ 2 years (22.55%) or > 2 years (3.92%) in age. Gender and age were not associated with the cases of co-infections (p˂0.05). The seasonality data indicated one peak of the infection occurring in January 2017 which has decreased consecutively in the subsequent two years. These results demonstrate the prevalence and co-occurrence of enteric viruses in cases of infantile diarrhoea in Nsukka. Further molecular characterization of enteric virus strains, especially noroviruses, in this region would contribute significantly to global epidemiological data.

Supplementary Information

The online version contains supplementary material available at 10.1007/s13337-023-00821-2.

RT-PCR-based assessment of the SD Bioline Rota/Adeno Antigen-based test in infants with and without diarrhea

BACKGROUND

Rotavirus A (RVA) infections remain a major cause of severe acute diarrhea affecting children worldwide. To date, rapid diagnostic tests (RDT) are widely used to detect RVA. However, paediatricians question whether the RDT can still detect the virus accurately. Therefore, this study aimed to evaluate the performance of the rapid rotavirus test in comparison to the one-step RT-qPCR method.

METHODS

A cross-sectional study was conducted in Lambaréné, Gabon, from April 2018 to November 2019. Stool samples were collected from children under 5 years of age with diarrhoea or a history of diarrhoea within the last 24 h, and from asymptomatic children from the same communities. All stool samples were processed and analysed using the SD BIOLINE Rota/Adeno Ag RDT against a quantitative reverse transcription PCR (RT-qPCR), which is considered the gold standard.

RESULTS

For a total of 218 collected stool samples, the overall sensitivity of the RDT was 46.46% (confidence interval (CI) 36.38-56.77), with a specificity of 96.64% (CI 91.62-99.08) compared to one-step RT-qPCR. After confirming the presence or absence of RVA gastroenteritis, the RDT showed suitable results in detecting rotavirus A-associated disease, with a 91% concordance with the RT-qPCR. Furthermore, the performance of this test varied when correlated with seasonality, symptoms, and rotavirus genotype.

CONCLUSION

This RDT showed high sensitivity and was suitable for the detection of RVA in patients with RVA gastroenteritis, although some asymptomatic RVA shedding was missed by RT-qPCR. It could be a useful diagnostic tool, especially in low-income countries.

Acute Infectious Gastroenteritis: The Causative Agents, Omics-Based Detection of Antigens and Novel Biomarkers

Acute infectious gastroenteritis (AGE) is among the leading causes of mortality in children less than 5 years of age worldwide. There are many causative agents that lead to this infection, with rotavirus being the commonest pathogen in the past decade. However, this trend is now being progressively replaced by another agent, which is the norovirus. Apart from the viruses, bacteria such as Salmonella and Escherichia coli and parasites such as Entamoeba histolytica also contribute to AGE. These agents can be recognised by their respective biological markers, which are mainly the specific antigens or genes to determine the causative pathogen. In conjunction to that, omics technologies are currently providing crucial insights into the diagnosis of acute infectious gastroenteritis at the molecular level. Recent advancement in omics technologies could be an important tool to further elucidate the potential causative agents for AGE. This review will explore the current available biomarkers and antigens available for the diagnosis and management of the different causative agents of AGE. Despite the high-priced multi-omics approaches, the idea for utilization of these technologies is to allow more robust discovery of novel antigens and biomarkers related to management AGE, which eventually can be developed using easier and cheaper detection methods for future clinical setting. Thus, prediction of prognosis, virulence and drug susceptibility for active infections can be obtained. Case management, risk prediction for hospital-acquired infections, outbreak detection, and antimicrobial accountability are aimed for further improvement by integrating these capabilities into a new clinical workflow.