Evaluation of the RIDAQuick norovirus immunochromatographic test kit

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.

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.

Comparative Evaluation of Norovirus Infection in Children with Acute Gastroenteritis by Rapid Immunochromatographic Test, RT-PCR and Real-time RT-PCR

Immunochromatographic (IC) test for norovirus detection is a rapid and simple detection method. This study evaluated the sensitivity and specificity of a recent version of R-Biopharm RIDA®QUICK Norovirus IC assay for norovirus detection in fecal specimens from children hospitalized with acute gastroenteritis. Fecal specimens were tested by IC kit in comparison with gold standard reverse transcription polymerase chain reaction (RT-PCR) and real-time RT-PCR. The IC kit showed high sensitivity and specificity comparable with PCR-based methods. None of false positive and false negative was found and the assay did not cross-react with other gastroenteritis viruses. The IC assay could detect genogroup I.5 (GI.5) and a wide range of genotypes in the GII noroviruses including GII.3, GII.4, GII.6, GII.7, GII.14, GII.15, GII.21, and also newly emerging GII.17 norovirus. In conclusion, this norovirus IC kit could be an alternative choice for rapid screening or a quick diagnostic tool for norovirus detection in fecal specimens of acute gastroenteritis patients.

Identification and Characterization of Single-Chain Antibodies that Specifically Bind GI Noroviruses

Norovirus infections commonly lead to outbreaks of acute gastroenteritis and spread quickly, resulting in many health and economic challenges prior to diagnosis. Rapid and reliable diagnostic tests are therefore essential to identify infections and to guide the appropriate clinical responses at the point-of-care. Existing tools, including RT-PCR and enzyme immunoassays, pose several limitations based on the significant time, equipment and expertise required to elicit results. Immunochromatographic assays available for use at the point-of-care have poor sensitivity and specificity, especially for genogroup I noroviruses, thus requiring confirmation of results with more sensitive testing methods. Therefore, there is a clear need for novel reagents to help achieve quick and reliable results. In this study, we have identified two novel single-chain antibodies (scFvs)—named NJT-R3-A2 and NJT-R3-A3—that effectively detect GI.1 and GI.7 virus-like particles (VLPs) through selection of a phage display library against the P-domain of the GI.1 major capsid protein. The limits of detection by each scFv for GI.1 and GI.7 are 0.1 and 0.2 ng, and 6.25 and 25 ng, respectively. They detect VLPs with strong specificity in multiple diagnostic formats, including ELISAs and membrane-based dot blots, and in the context of norovirus-negative stool suspensions. The scFvs also detect native virions effectively in norovirus-positive clinical stool samples. Purified scFvs bind to GI.1 and GI.7 VLPs with equilibrium constant (K_D) values of 27 nM and 49 nM, respectively. Overall, the phage-based scFv reagents identified and characterized here show utility for detecting GI.1 and GI.7 noroviruses in multiple diagnostic assay formats with strong specificity and sensitivity, indicating promise for integration into existing point-of-care tests to improve future diagnostics.

Development of a Nanobody-Based Lateral Flow Immunoassay for Detection of Human Norovirus

We previously identified a Nanobody (termed Nano-85) that bound to a highly conserved region on the norovirus capsid. In this study, the Nanobody was biotinylated and gold conjugated for a lateral flow immunoassay (termed Nano-IC). We showed that the Nano-IC assay was capable of detecting at least four antigenically distinct GII genotypes, including the newly emerging GII.17. In the clinical setting, the Nano-IC assay had sensitivities equivalent to other commercially available lateral flow systems. The Nano-IC method was capable of producing results in ~5 min, which makes this method useful in settings that require rapid diagnosis, such as cruise ship outbreaks and elder care facilities. The Nano-IC assay has several advantages over antibody-based IC methods: for example, Nanobodies can be readily produced in large quantities, they are generally more stable than conventional antibodies, and the Nanobody binding sites can be easily obtained by X-ray crystallography.

Human noroviruses are the dominant cause of outbreaks of acute gastroenteritis. These viruses are usually detected by molecular methods, including reverse transcriptase PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA). Human noroviruses are genetically and antigenically diverse, with two main genogroups that are further subdivided into over 40 different genotypes. During the past decade, genogroup 2 genotype 4 (GII.4) has dominated in most countries, but recently, viruses belonging to GII.17 have increased in prevalence in a number of countries. A number of commercially available ELISAs and lateral flow immunoassays were found to have lower sensitivities to the GII.17 viruses, indicating that the antibodies used in these methods may not have a high level of cross-reactivity. In this study, we developed a rapid Nanobody-based lateral flow immunoassay (Nano-immunochromatography [Nano-IC]) for the detection of human norovirus in clinical specimens. The Nano-IC assay detected virions from two GII.4 norovirus clusters, which included the current dominant strain and a novel variant strain. The Nano-IC method had a sensitivity of 80% and specificity of 86% for outbreak specimens. Norovirus virus-like particles (VLPs) representing four genotypes (GII.4, GII.10, GII.12, and GII.17) could be detected by this method, demonstrating the potential in clinical screening. However, further modifications to the Nano-IC method are needed in order to improve this sensitivity, which may be achieved by the addition of other broadly reactive Nanobodies to the system.

IMPORTANCE We previously identified a Nanobody (termed Nano-85) that bound to a highly conserved region on the norovirus capsid. In this study, the Nanobody was biotinylated and gold conjugated for a lateral flow immunoassay (termed Nano-IC). We showed that the Nano-IC assay was capable of detecting at least four antigenically distinct GII genotypes, including the newly emerging GII.17. In the clinical setting, the Nano-IC assay had sensitivities equivalent to other commercially available lateral flow systems. The Nano-IC method was capable of producing results in ~5 min, which makes this method useful in settings that require rapid diagnosis, such as cruise ship outbreaks and elder care facilities. The Nano-IC assay has several advantages over antibody-based IC methods: for example, Nanobodies can be readily produced in large quantities, they are generally more stable than conventional antibodies, and the Nanobody binding sites can be easily obtained by X-ray crystallography.

Evaluation of the updated RIDA®QUICK (Version N1402) immunochromatographic assay for the detection of norovirus in clinical specimens

The sensitivity and specificity of the R-Biopharm RIDA(®)QUICK (N1402) immunochromatography assay for norovirus detection was examined using fecal material from Australian gastroenteritis incidents. The study involved the analysis of 3 groups of specimens; group 1 comprised 100 norovirus open reading frame (ORF) 1 RT-PCR positive specimens; group 2 comprised 100 ORF 1 RT-PCR norovirus negative specimens and group 3 comprised 12 specimens containing common gastroenteritis viruses other than norovirus. The RIDA(®)QUICK (N1402) assay detected both GI and GII norovirus and had an overall sensitivity of 87%. Genotype analysis of the capsid region of the genome (ORF 2) indicated the RIDA(®)QUICK (N1402) assay could detect a range of genotypes including GI.1, GI.2, GI.3, GI.4, GI.5, GII.3, GII.4 (including variants GII.4 (2009-like), GII.4 (2012), GII.4 (2012-like) and GII.4 (unknown)), GII.6, GII.13 and GII.21. The assay had good sensitivity for both GI and GII norovirus. The assay had a specificity of 97% and did not cross react with a number of common fecal viruses. However, one of eight rotavirus positive, norovirus negative specimens gave a positive result; rotavirus cannot be taken as the cause of such a false positive but cannot be excluded either. The kit was quick and easy to use and would be valuable in point-of-care testing.

[Interests and limitations of rapid diagnostic tests for respiratory and gastrointestinal viral diseases]

Les tests de dépistage rapide (TDR) basés sur la technique d’immunochromatographie sont très répandus pour le diagnostic des maladies infectieuses. Dans le cadre des infections respiratoires virales, il s’agit essentiellement de tests pour le diagnostic de la grippe et des infections à virus respiratoire syncytial (VRS). Pour le diagnostic des gastroentérites virales, ce sont des tests de détection des rotavirus, adénovirus, norovirus et astrovirus qui peuvent être utilisés. Les TDR pour les infections à VRS et les gastroentérites sont utilisés essentiellement dans le cadre de la pathologie pédiatrique. Ces tests présentent généralement une spécificité élevée mais une sensibilité modeste par rapport aux techniques moléculaires. Ce sont donc surtout des tests de dépistages et leur négativité ne permet pas d’exclure le diagnostic.

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.

Detection of viruses by counting single fluorescent genetically biotinylated reporter immunophage using a lateral flow assay

We demonstrated a lateral flow immunoassay (LFA) for detection of viruses using fluorescently labeled M13 bacteriophage as reporters and single-reporter counting as the readout. AviTag-biotinylated M13 phage were functionalized with antibodies using avidin-biotin conjugation and fluorescently labeled with AlexaFluor 555. Individual phage bound to target viruses (here MS2 as a model) captured on an LFA membrane strip were imaged using epi-fluorescence microscopy. Using automated image processing, we counted the number of bound phage in micrographs as a function of target concentration. The resultant assay was more sensitive than enzyme-linked immunosorbent assays and traditional colloidal-gold nanoparticle LFAs for direct detection of viruses.

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 of an immunochromatographic assay kit using fluorescent silica nanoparticles for rapid diagnosis of Acanthamoeba keratitis

We developed an immunochromatographic assay kit that uses fluorescent silica nanoparticles bound to anti-Acanthamoeba antibodies (fluorescent immunochromatographic assay [FICGA]) and evaluated its efficacy for the detection of Acanthamoeba and diagnosis of Acanthamoeba keratitis (AK). The sensitivity of the FICGA kit was evaluated using samples of Acanthamoeba trophozoites and cysts diluted to various concentrations. A conventional immunochromatographic assay kit with latex labels (LICGA) was also evaluated to determine its sensitivity in detecting Acanthamoeba trophozoites. To check for cross-reactivity, the FICGA was performed by using samples of other common causative pathogens of infectious keratitis, such as Pseudomonas aeruginosa, Staphylococcus aureus, Staphylococcus epidermidis, and Candida albicans. Corneal scrapings from patients with suspected AK were tested with the FICGA kit to detect the presence of Acanthamoeba, and the results were compared with those of real-time PCR. The FICGA kit detected organisms at concentrations as low as 5 trophozoites or 40 cysts per sample. There were no cross-reactivities with other pathogens. The FICGA was approximately 20 times more sensitive than the LICGA for the detection of Acanthamoeba trophozoites. The FICGA kit yielded positive results for all 10 patients, which corresponded well with the real-time PCR results. The FICGA kit demonstrated high sensitivity for the detection of Acanthamoeba and may be useful for the diagnosis of AK.

Point-of-care tests for infection control: should rapid testing be in the laboratory or at the front line?

BACKGROUND

A point-of-care test (POCT) offers a rapid result to manage a patient immediately. The presumed simplicity of such tests belies observed variation between personnel in performing and interpreting results when not appropriately trained. The number of point-of-care devices being developed for the diagnosis of infectious diseases is increasing; by understanding the limitations associated with their use, such tests for infection control purposes may be possible.

AIM

To review the expanding repertoire of POCTs for the diagnosis of infectious diseases and to assess their utility as tools to aid in the reduction of hospital-acquired infection and outbreak management.

METHODS

A systematic review using PubMed and Scopus of published literature on the subject of POCTs for the diagnosis of infectious diseases.

FINDINGS

Although the number of publications describing POCTs is increasing, there remains a paucity of literature describing their use in a clinical setting. Of the literature reviewed, POCTs for the diagnosis of respiratory syncytial virus and norovirus have the greatest utility in an infection control setting, although the data suggest that sensitivity and training issues might be a problem. The future generation of POCT devices is likely to be molecular-based, improving sensitivity but at a significant cost to the user.

CONCLUSIONS

POCTs have a role in infection control but currently the lack of good, consistent clinical data surrounding their use outside of the laboratory is a limiting factor in their implementation.

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.

Coinfection in acute gastroenteritis predicts a more severe clinical course in children

The objectives of this study were to determine the incidence of enteric pathogens causing acute gastroenteritis (AGE) among hospitalized children in a large Italian hospital, to measure the incidence of coinfections, and to compare the clinical characteristics of those infected with one versus multiple agents. A prospective study was conducted from March 2010 to April 2011 at the Bambino Gesù Pediatric Hospital in Rome, Italy. All patients between 1 month and 16 years of age admitted to the Pediatric Department with a diagnosis of AGE were eligible for enrollment. Two stool samples for each patient were tested for gastrointestinal pathogens. We summarized the clinical severity of episodes, describing the duration of diarrhea, duration and frequency of vomiting, fever, and severity of dehydration. All the patients underwent medical evaluation with estimation of dehydration. One or more etiological agents were detected in 151 out of 232 patients (65.1%), while we did not detect any etiological agent in 81 (34.9%). Rotavirus was detected in 96 (63.6%), adenovirus in 17 (11.2%), norovirus in 7 (4.6%), toxin-producing Clostridium difficile in 23 (15.2%), Salmonella spp. in 15 (9.9%, B group in 12/15 and D group in 3/15), C. perfringens in 12 (7.9%), Campylobacter spp. in 6 (4%), and verotoxigenic Escherichia coli (VTEC) in 2 (1.3%). In 27 children out of 151 (17.9%), we found evidence of coinfection. Coinfection with rotavirus and toxin-producing C. difficile was the most common (63%). Children with coinfection had a more severe clinical presentation and had a higher probability to be severely dehydrated, independently of age and living community type.

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.