Evaluation of a new immunochromatographic assay kit for the rapid detection of norovirus in fecal specimens

Diagnostic Accuracy of Immunochromatographic Tests for the Detection of Norovirus in Stool Specimens: a Systematic Review and Meta-Analysis

Noroviruses are the leading cause of acute gastroenteritis in all age groups and constitute a major health and economic burden worldwide. This systematic review and meta-analysis aimed to determine the diagnostic accuracy of immunochromatographic tests (ICTs) for the detection of norovirus in stool specimens, which has not been performed previously. In this systematic review and meta-analysis (registered on PROSPERO, CRD42020186911), we searched Medline/PubMed, Embase, Cochrane Library, and Web of Science for all studies published up to 16 May 2020. The values for sensitivity, specificity, positive likelihood ratio (LR+), negative likelihood ratio (LR-), and diagnostic odds ratio (DOR) of ICTs with 95% confidence interval (CI) were pooled using a bivariate random-effects model. The summary receiver operating characteristic curve and area under the curve were used to summarize overall test accuracy. We included 43 studies describing 7,428 samples. The overall estimates of sensitivity, specificity, LR+, LR-, DOR, and accuracy of ICT for diagnosing norovirus were 0.61 (95% CI, 0.54 to 0.67), 0.97 (95% CI, 0.95 to 0.98), 17.08 (95% CI, 11.15 to 26.18), 0.40 (95% CI, 0.34 to 0.46), 53.9 (95% CI, 31.32 to 92.78), and 0.928, respectively. Significant differences in pooled sensitivities were noted between age groups and in pooled DOR and LR+ between genogroups of included samples. ICT provides low sensitivity but high specificity and accuracy for detecting norovirus. Thus, an ICT for norovirus can be a rapid and convenient way for identifying patients early; however, a negative result cannot rule out norovirus infection and should be confirmed by a reference test.

Broad-range and effective detection of human noroviruses by colloidal gold immunochromatographic assay based on the shell domain of the major capsid protein

BACKGROUND

Human noroviruses (HuNoVs) are a major cause of nonbacterial gastroenteritis in all age groups worldwide. HuNoVs can be detected in vitro using molecular assays such as RT-PCR and RT-qPCR. However, these molecular-based techniques require special equipment, unique reagents, experienced personnel, and extended time to obtain results. Besides, the diversity of viral genotypes is high. Therefore, methods that are rapid, broad-range and effective in the detection of HuNoVs are desiderated for screening the feces or vomit of infected people during outbreaks.

RESULTS

In this study, a colloidal-gold-based immunochromatographic assay (ICA) was developed for effective detection of HuNoVs in clinical samples. Monoclonal antibodies (MAbs) against the shell (S) domain in the major capsid protein of HuNoVs were used in the ICA. The limitations of detection for HuNoVs in clinical samples were 1.2 × 106 genomic copies per gram of stool sample (gc/g) and 4.4 × 105 gc/g for genogroup I and II (GI and GII) HuNoVs, respectively. A total of 122 clinical samples were tested for HuNoVs by ICA and compared against RT-qPCR. The relative sensitivity, specificity and agreement of ICA was 84.2% (95% CI: 83.6-84.8%), 100.0% (95% CI: 98.5-100.0%) and 87.7% (95% CI: 85.6-89.8%), respectively. No cross-reaction with other common enteric viruses or bacteria was observed. The ICA detected a broad range of genotypes, including GI.1, GI.3, GI.4, GI.6, GI.14, GII.2, GII.3, GII.4, GII.6, GII.13, and GII.17 HuNoVs.

CONCLUSIONS

This study demonstrates that ICA targeting the S domain of VP1 is a promising candidate for effectively identifying the different genotypes of HuNoVs in clinical samples with high sensitivity and specificity.

Performance evaluation of Automated Fluorescent Immunoassay System ROTA and NORO for detection of rotavirus and norovirus: A comparative study of assay performance with RIDASCREEN® Rotavirus and Norovirus

Background

The Automated Fluorescent Immunoassay System ROTA (AFIAS‐Rota) and NORO (AFIAS‐Noro) assays (Boditech Med Inc.) are newly developed diagnostic tests for rotavirus and norovirus infections.

Methods

Performance of AFIAS‐Rota/Noro assays was evaluated in comparison with RIDASCREEN^® Rotavirus and Norovirus ELISA kits (R‐Biopharm) using clinical stool samples submitted from November 2018 to January 2019. Multiplex real‐time reverse transcription‐polymerase chain reaction was used as reference method.

Results

A total of 256 clinical specimens were analyzed. AFIAS‐Rota and RIDASCREEN Rotavirus had almost perfect agreement (Kappa value = 0.95), and substantial agreement was observed between AFIAS‐Noro and RIDASCREEN Norovirus (Kappa value = 0.80). For detection of rotavirus, AFIAS and RIDASCREEN assays showed satisfactory diagnostic sensitivity (100% and 97.8%, respectively) and specificity (99.5% and 99.1%). For detection of norovirus, the RIDASCREEN assay showed significantly higher sensitivity than the AFIAS‐Noro (86.0% and 66.0%, respectively; P = .002). Analytic specificity of AFIAS‐Rota/Noro assays showed no cross‐reactivity against any other bacteria (14 strains) or viruses (2 strains). Hands‐on time (6 minutes) and turnaround time (26 minutes) required to perform AFIAS assays were much shorter than those required for RIDASCREEN assays (20 and 150 minutes, respectively).

Conclusion

The AFIAS‐Rota/Noro assays showed overall excellent agreement with the RIDASCREEN assays. Although the AFIAS‐Noro assay exhibited lower sensitivity than the RIDASCREEN Norovirus assay for detection of norovirus, the AFIAS‐Rota/Noro assays could be useful as a rapid initial screening test in clinical laboratories due to its convenience and rapid turnaround time.

Advances in Diagnostic Approaches for Viral Etiologies of Diarrhea: From the Lab to the Field

The applications of correct diagnostic approaches play a decisive role in timely containment of infectious diseases spread and mitigation of public health risks. Nevertheless, there is a need to update the diagnostics regularly to capture the new, emergent, and highly divergent viruses. Acute gastroenteritis of viral origin has been identified as a significant cause of mortality across the globe, with the more serious consequences seen at the extremes of age groups (young and elderly) and immune-compromised individuals. Therefore, significant advancements and efforts have been put in the development of enteric virus diagnostics to meet the WHO ASSURED criteria as a benchmark over the years. The Enzyme-Linked Immunosorbent (ELISA) and Polymerase Chain Reaction (PCR) are the basic assays that provided the platform for development of several efficient diagnostics such as real-time RT-PCR, loop-mediated isothermal amplification (LAMP), polymerase spiral reaction (PSR), biosensors, microarrays and next generation sequencing. Herein, we describe and discuss the applications of these advanced technologies in context to enteric virus detection by delineating their features, advantages and limitations.

Sensitive detection of norovirus using phage nanoparticle reporters in lateral-flow assay

Noroviruses are recognized worldwide as the principal cause of acute, non-bacterial gastroenteritis, resulting in 19-21 million cases of disease every year in the United States. Noroviruses have a very low infectious dose, a short incubation period, high resistance to traditional disinfection techniques and multiple modes of transmission, making early, point-of-care detection essential for controlling the spread of the disease. The traditional diagnostic tools, electron microscopy, RT-PCR and ELISA require sophisticated and expensive instrumentation, and are considered too laborious and slow to be useful during severe outbreaks. In this paper we describe the development of a new, rapid and sensitive lateral-flow assay using labeled phage particles for the detection of the prototypical norovirus GI.1 (Norwalk), with a limit of detection of 10⁷ virus-like particles per mL, one hundred-fold lower than a conventional gold nanoparticle lateral-flow assay using the same antibody pair.

Characteristics and outcomes of patients diagnosed with norovirus gastroenteritis after allogeneic hematopoietic stem cell transplantation based on immunochromatography

Norovirus gastroenteritis (NV-GE) is a highly transmittable disease that can lead to fatal outcomes in vulnerable populations including patients after hematopoietic stem cell transplantation (HSCT). Prompt detection of NV is therefore important for HSCT recipients. Immunochromatography (IC) can be used to easily and rapidly diagnose NV-GE by detecting NV antigens. In this study, we examined 642 stool specimens in patients who developed diarrhea after allogeneic HSCT between January 2007 and June 2011. NV was detected in 10 of 350 (2.9 %) HSCT recipients. The median onset of symptoms was 36 days (range 3-93) after HSCT. The median duration of symptoms was 42 days (3-135). A second or subsequent allogeneic HSCT was associated with a higher incidence of NV-GE (P = 0.034). Of four patients who underwent colonoscopy, two showed intestinal graft-versus-host disease (GVHD) histopathology, whereas the other two showed no evidence of GVHD, and thus no need for intensified immunosuppression. None of the patients died of NV-GE. In conclusion, IC may be useful in the differential diagnosis of diarrhea after allogeneic HSCT, and could enable the appropriate adjustment of immunosuppressive drugs and prompt preventive measures.

Norovirus

Norovirus, an RNA virus of the family Caliciviridae, is a human enteric pathogen that causes substantial morbidity across both health care and community settings. Several factors enhance the transmissibility of norovirus, including the small inoculum required to produce infection (<100 viral particles), prolonged viral shedding, and its ability to survive in the environment. In this review, we describe the basic virology and immunology of noroviruses, the clinical disease resulting from infection and its diagnosis and management, as well as host and pathogen factors that complicate vaccine development. Additionally, we discuss overall epidemiology, infection control strategies, and global reporting efforts aimed at controlling this worldwide cause of acute gastroenteritis. Prompt implementation of infection control measures remains the mainstay of norovirus outbreak management.

Development and hemocompatibility testing of nitric oxide releasing polymers using a rabbit model of thrombogenicity

Hemocompatibility is the goal for any biomaterial contained in extracorporeal life supporting medical devices. The hallmarks for hemocompatibility include nonthrombogenicity, platelet preservation, and maintained platelet function. Both in vitro and in vivo assays testing for compatibility of the blood/biomaterial interface have been used over the last several decades to ascertain if the biomaterial used in medical tubing and devices will require systemic anticoagulation for viability. Over the last 50 years systemic anticoagulation with heparin has been the gold standard in maintaining effective extracorporeal life supporting. However, the biomaterial that maintains effective ECLS without the use of any systemic anticoagulant has remained elusive. In this review, the in vivo 4-h rabbit thrombogenicity model genesis will be described with emphasis on biomaterials that may require no systemic anticoagulation for extracorporeal life supporting longevity. These novel biomaterials may improve extracorporeal circulation hemocompatibility by preserving near resting physiology of the major blood components, the platelets and monocytes. The rabbit extracorporeal circulation model provides a complete assessment of biomaterial interactions with the intrinsic coagulation players, the circulating platelet and monocytes. This total picture of blood/biomaterial interaction suggests that this rabbit thrombogenicity model could provide a standardization for biomaterial hemocompatibility testing.

Prevalence of human astrovirus in patients with acute gastroenteritis

The prevalence of human astroviruses was tested in patients with acute gastroenteritis by using conventional duplex reverse transcription (RT)-PCR and electrophoresis. Diarrheal fecal samples were collected from 9,597 patients at local hospitals in Seoul. The prevalence of astroviruses was 1.0% (94/9,597 patients; mostly infants), and that of sapoviruses was 0.1% (14/9,597 patients). Age- and gender-wise analyses were carried out on 29 astrovirus-positive patients having complete information on file regarding their age, gender, and other particulars. The results were higher in patients of ages 0 to 14 yr, and 69.0% of the astrovirus-positive patients were females, of which 69.2% were infants (0 to 12 months), and 61.5% were 1-4 yr old. Notably, in the case of 5 to 78-yr-old acute gastroenteritis patients, 100% were females.

Evaluation of the Bioline Standard Diagnostics SD immunochromatographic norovirus detection kit using fecal specimens from Australian gastroenteritis incidents

Human norovirus is a major cause of both sporadic cases and outbreaks of gastroenteritis and comprises two main genogroups (GI and GII) which, in turn, comprise a variety of genotypes. The current study examined the efficacy of the Bioline SD kit using fecal material from Australian gastroenteritis incidents. At best, the SD kit had a sensitivity of 62%. Freezing and thawing specimens before testing significantly improved sensitivity. The SD kit had a specificity of 98.6%. Genotype analysis (Open Reading Frame 2) indicated the SD kit could detect a range of genotypes and genotype variants including GI.1, GI.3, GI.4, GII.1, GII.3, GII.4 (unclassified), GII.4 (2006b), GII.4 (2009), GII.4 (2012) and GII.6 but the kit failed to detect GI.2 and GII.2 norovirus. The kit did not cross-react with a number of common fecal viruses including astrovirus, sapovirus, rotavirus or adenovirus. The kit was very easy to use and would be valuable in point-of-care testing.

Molecular detection and genotyping of noroviruses

Noroviruses (NoVs) are a major cause of gastroenteritis worldwide in humans and animals and are known as very infectious viral agents. They are spread through feces and vomit via several transmission routes involving person-to-person contact, food, and water. Investigation of these transmission routes requires sensitive methods for detection of NoVs. As NoVs cannot be cultivated to date, detection of these viruses relies on the use of molecular methods such as (real-time) reverse transcriptase polymerase chain reaction (RT-PCR). Regardless of the matrix, detection of NoVs generally requires three subsequent steps: a virus extraction step, RNA purification, and molecular detection of the purified RNA, occasionally followed by molecular genotyping. The current review mainly focused on the molecular detection and genotyping of NoVs. The most conserved region in the genome of human infective NoVs is the ORF1/ORF2 junction and has been used as a preferred target region for molecular detection of NoVs by methods such as (real-time) RT-PCR, NASBA, and LAMP. In case of animal NoVs, broad range molecular assays have most frequently been applied for molecular detection. Regarding genotyping of NoVs, five regions situated in the polymerase and capsid genes have been used for conventional RT-PCR amplification and sequencing. As the expected levels of NoVs on food and in water are very low and inhibition of molecular methods can occur in these matrices, quality control including adequate positive and negative controls is an essential part of NoV detection. Although the development of molecular methods for NoV detection has certainly aided in the understanding of NoV transmission, it has also led to new problems such as the question whether low levels of human NoV detected on fresh produce and shellfish could pose a threat to public health.

Evaluation of 4 immunochromatographic tests for rapid detection of norovirus in faecal samples

BACKGROUND

The rapid detection of noroviruses is essential to implement measures to reduce the rapid spread of gastroenteritis infections they cause, notably in institutions.

OBJECTIVES

To evaluate 4 rapid immunochromatographic tests: RIDA(®)QUICK Norovirus, ImmunoCardSTAT!(®) Norovirus, NOROTOP(®) and SD BIOLINE NOROVIRUS by determining their sensitivity and specificity on a large panel of samples representing 11 genotypes of norovirus genogroup I and 14 of genogroup II, and their cross-reactivity with other enteric viruses.

STUDY DESIGN

Thawed stool samples containing norovirus genogroup I or II or other enteric viruses, and negative samples, were tested by the 4 assays and compared to the reference standard RT-PCR. Fresh stool samples were also tested by RIDA(®)QUICK.

RESULTS

The sensitivity of RIDA(®)QUICK, ImmunoCardSTAT!(®), NOROTOP(®) and SD BIOLINE for the detection of norovirus genogroup I on thawed samples was 17%, 26%, 52% and 23%, respectively. For genogroup II, the sensitivity was 64%, 39%, 50% and 54%, respectively. For GII.4, the main circulating genotype, the sensitivity was 78%, 59%, 61% and 67%, respectively. For all tests, the specificity was 100% and no cross-reactivity with other enteric viruses was observed. The sensitivity of RIDA(®)QUICK on fresh stool samples positive for GII.4 was 71%.

CONCLUSIONS

Knowing that most gastroenteritis cases are due to GII.4, the immunochromatographic tests may be useful for preliminary screening, notably in outbreaks. However, negative samples need to be tested using RT-PCR methods.

Evaluation of the SD Bioline Norovirus rapid immunochromatography test using fecal specimens from Korean gastroenteritis patients

The analytical and clinical performance of a new rapid immunochromatography test, the SD Bioline Norovirus test, was evaluated for the detection of human norovirus in fecal specimens. The analytical performance studies were performed for detection limit, reproducibility, cross-reactivity, and interference. For comparison, 92 norovirus-positive stool samples and 126 norovirus-negative samples for which the results were confirmed by 2 different real-time PCR kits were used. The rapid immunochromatography test detected the equivalent of 4.48×10(6) copies/mL of the norovirus genome in stool samples. On performing the repeatability/reproducibility test, samples above this concentration all provided positive results (100%) and 97.8% of the samples slightly below this concentration (2.45×10(6) copies/mL) provided negative results. No cross-reactivity or interference was detected. Positive percent agreement (sensitivity), negative percent agreement (specificity), and overall percent agreement of the rapid immunochromatography test compared with testing by real-time PCR were 90.2%, 100%, and 95.9%, respectively. In addition, the rapid immunochromatography test was completed within 20 min. The SD Bioline Norovirus test was, therefore, easier and more rapid to perform and showed excellent reproducibility, no cross-reactivity, no interference, and high agreement compared with real-time PCR. Thus, this test is useful for rapid screening to identity norovirus infection.

Updates on the genetic variations of norovirus in sporadic gastroenteritis in Chungnam Korea, 2009-2010

Previously, we explored the epidemic pattern and molecular characterization of noroviruses (NoVs) isolated in Chungnam, Korea in 2008, and the present study extended these observations to 2009 and 2010. In Korea, NoVs showed the seasonal prevalence from late fall to spring, and widely detected in preschool children and peoples over 60 years of age. Epidemiological pattern of NoV was similar in 2008 and in 2010, but pattern in 2009 was affected by pandemic influenza A/H1N1 2009 virus. NoV-positive samples were subjected to sequence determination of the capsid gene region, which resolved the isolated NoVs into five GI (2, 6, 7, 9 and 10) and eleven GII genotypes (1, 2, 3, 4, 6, 7, 8, 12, 13, 16 and 17). The most prevalent genotype was GII.4 and occupied 130 out of 211 NoV isolates (61.6%). Comparison of NoV GII.4 of prevalent genotype in these periods with reference strains of the same genotype was conducted to genetic analysis by a phylogenetic tree. The NoV GII.4 strains were segregated into seven distinct genetic groups, which are supported by high bootstrap values and previously reported clusters. All Korean NoV GII.4 strains belonged to either VI cluster or VII cluster. The divergence of nucleotide sequences within VI and VII intra-clusters was > 3.9% and > 3.5%, respectively. The "Chungnam(06-117)/2010" strain which was isolated in June 2010 was a variant that did not belong to cluster VI or VII and showed 5.8-8.2%, 6.2-8.1% nucleotide divergence with cluster VI and VII, respectively.