---
title: "Rhinoswab vs joint nose-and-throat swabs: Agreement for influenza and SARS-CoV-2 RT-qPCR in sympto"
id: "plos-one-7-diagnostic-agreement-between-rhinoswabs-and-joint-nose-and-throat-swabs-for-the"
canonical_url: "https://medichelpline.com/clinical-feed/plos-one-7-diagnostic-agreement-between-rhinoswabs-and-joint-nose-and-throat-swabs-for-the"
content_type: "clinical_feed_article"
specialty: "Infectious Disease"
source_name: "PLOS ONE (Medicine)"
source_url: "https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869"
published_at: "2026-08-11T14:00:00.000Z"
evidence_level: "Journal Feed"
license: "CC-BY-NC-4.0 / Informational Use"
---
# Rhinoswab vs joint nose-and-throat swabs: Agreement for influenza and SARS-CoV-2 RT-qPCR in sympto
## Provenance & Clinical Metadata
- **Canonical URL:** https://medichelpline.com/clinical-feed/plos-one-7-diagnostic-agreement-between-rhinoswabs-and-joint-nose-and-throat-swabs-for-the
- **Specialty:** [Infectious Disease](https://medichelpline.com/clinical-feed/infectious-disease.md)
- **Primary Source:** PLOS ONE (Medicine)
- **Source URL:** [Original Journal Publication](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869)
- **Published At:** 2026-08-11T14:00:00.000Z
- **Evidence Rating:** Journal Feed
## Executive GIST (TL;DR)
- Study compared paired **Rhinoswab** anterior nasal swabs with paired joint nose-and-throat swabs (**NTS**) for RT-qPCR detection of **influenza A**, **influenza B**, and **SARS-CoV-2** in symptomatic ambulatory patients in Hong Kong. - Enrollment occurred between May 3, 2023 and April 29, 2024; 531 patients were invited and 488 (91.9%) provided paired samples. - Participants were outpatients with febrile acute respiratory illness (≥2 respiratory symptoms within 3 days of onset); mean age 25 years; 55.5% female. - Samples were tested by RT-qPCR with a positivity threshold of **Ct < 40**; human RNase P was used as an internal control. - Concordance between Rhinoswab and joint NTS was high: 98.0% for influenza A, 99.0% for influenza B, and 99.0% for SARS-CoV-2. - Cohen’s kappa indicated near-perfect agreement: 0.95 (influenza A), 0.94 (influenza B), and 0.92 (SARS-CoV-2). - Ct values from Rhinoswab correlated with NTS Ct values (r = 0.76 for influenza A, 0.818 for influenza B, 0.729 for SARS-CoV-2; RNase P r = 0.616). - Most discordant specimens (16 of 18, 88.9%) had higher Ct values (≥30), indicating low viral loads in discordant pairs. - Collection order: joint NTS first, then Rhinoswab; Rhinoswab collection followed manufacturer instructions and included a junior version for children. - Authors conclude **Rhinoswabs** are a minimally invasive, viable alternative to joint NTS for supervised RT-qPCR respiratory virus testing in symptomatic outpatients. - Study data and code are publicly available in a GitHub repository; funding sources and competing interests are reported in the article.
## Clinical Analysis & Structured Key Points
[ Skip to main content ](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#main-content) Advertisement * [plos.org](https://plos.org/) * [Create account](https://community.plos.org/registration/new) * [Sign in](https://journals.plos.org/user/secure/login?page=%2Fplosone%2Farticle%3Fid%3D10.1371%2Fjournal.pone.0355869) * * About * Browse * Publish * [](https://journals.plos.org/plosone/ "PLOS One") * Search [advanced search](https://journals.plos.org/plosone/search) * [Browse Topics](https://journals.plos.org/plosone/subjectAreaBrowse) Browse Subject Areas ? Click through the PLOS taxonomy to find articles in your field. For more information about PLOS Subject Areas, click [here](https://github.com/PLOS/plos-thesaurus/blob/master/README.md "Link opens in new window"). [](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869) [](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869) * 0 [Save](https://journals.plos.org/plosone/article/metrics?id=10.1371/journal.pone.0355869#savedHeader) [Total Mendeley and Citeulike bookmarks.](https://journals.plos.org/plosone/article/metrics?id=10.1371/journal.pone.0355869#savedHeader) * 0 [Citation](https://journals.plos.org/plosone/article/metrics?id=10.1371/journal.pone.0355869#citedHeader) [Paper's citation count computed by Dimensions.](https://journals.plos.org/plosone/article/metrics?id=10.1371/journal.pone.0355869#citedHeader) * 25 [View](https://journals.plos.org/plosone/article/metrics?id=10.1371/journal.pone.0355869#viewedHeader) [PLOS views and downloads.](https://journals.plos.org/plosone/article/metrics?id=10.1371/journal.pone.0355869#viewedHeader) * 0 [Share](https://journals.plos.org/plosone/article/metrics?id=10.1371/journal.pone.0355869#discussedHeader) [Sum of Facebook, Twitter, Reddit and Wikipedia activity.](https://journals.plos.org/plosone/article/metrics?id=10.1371/journal.pone.0355869#discussedHeader) Open Access Peer-reviewed Research Article # Diagnostic agreement between Rhinoswabs and joint nose and throat swabs for the detection of influenza and SARS-CoV-2 among symptomatic ambulatory patients in Hong Kong * Caitriona Murphy, Roles Conceptualization, Formal analysis, Writing – original draft Affiliation World Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China [ ![ORCID logo](https://journals.plos.org/resource/img/orcid_16x16.png) https://orcid.org/0009-0004-6570-0582 ](https://orcid.org/0009-0004-6570-0582 "ORCID Registry") ⨯ * Samuel M. S. Cheng, Roles Data curation, Writing – review & editing Affiliation World Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China [ ![ORCID logo](https://journals.plos.org/resource/img/orcid_16x16.png) https://orcid.org/0000-0001-7293-2331 ](https://orcid.org/0000-0001-7293-2331 "ORCID Registry") ⨯ * Loretta Mak, Roles Data curation, Writing – review & editing Affiliation World Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China ⨯ * Hau Chi So, Roles Data curation, Writing – review & editing Affiliation World Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China [ ![ORCID logo](https://journals.plos.org/resource/img/orcid_16x16.png) https://orcid.org/0000-0003-3119-1527 ](https://orcid.org/0000-0003-3119-1527 "ORCID Registry") ⨯ * Dennis K. M. Ip, Roles Conceptualization, Writing – review & editing Affiliation World Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China ⨯ * Malik Peiris, Roles Writing – review & editing Affiliations World Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China, Centre of Immunology and Infection, Hong Kong Science and Technology Park, Hong Kong Special Administrative Region, China ⨯ * Benjamin J. Cowling Roles Conceptualization, Writing – review & editing * E-mail: bcowling@hku.hk Affiliation World Health Organization Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, The University of Hong Kong, Hong Kong Special Administrative Region, China [ ![ORCID logo](https://journals.plos.org/resource/img/orcid_16x16.png) https://orcid.org/0000-0002-6297-7154 ](https://orcid.org/0000-0002-6297-7154 "ORCID Registry") ⨯ # Diagnostic agreement between Rhinoswabs and joint nose and throat swabs for the detection of influenza and SARS-CoV-2 among symptomatic ambulatory patients in Hong Kong * Caitriona Murphy, * Samuel M. S. Cheng, * Loretta Mak, * Hau Chi So, * Dennis K. M. Ip, * Malik Peiris, * Benjamin J. Cowling ![PLOS](https://journals.plos.org/resource/img/logo-plos-full-color.svg) x * Published: August 11, 2026 * * [Article](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869) * [Authors](https://journals.plos.org/plosone/article/authors?id=10.1371/journal.pone.0355869) * [Metrics](https://journals.plos.org/plosone/article/metrics?id=10.1371/journal.pone.0355869) * [Comments](https://journals.plos.org/plosone/article/comments?id=10.1371/journal.pone.0355869) * [Media Coverage](http://plos.altmetric.com/details/doi/10.1371/journal.pone.0355869) * [Peer Review](https://journals.plos.org/plosone/article/peerReview?id=10.1371/journal.pone.0355869) * [Abstract](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#abstract0) * [Background](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#sec006) * [Objectives](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#sec007) * [Study design](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#sec008) * [Results](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#sec012) * [Discussion](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#sec013) * [Supporting information](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#sec014) * [Acknowledgments](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#ack) * [References](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#references) * [Reader Comments](https://journals.plos.org/plosone/article/comments?id=10.1371/journal.pone.0355869) * [Figures](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869) ![Accessible Data Icon](https://journals.plos.org/resource/img/accessible_data.svg)Accessible Data [ See the data ![Link Icon](https://journals.plos.org/resource/img/data_link_icon.svg) ](https://github.com/caitmurphy/rhinoswab_concordance) This article includes the Accessible Data icon, an experimental feature to encourage data sharing and reuse. [Find out how research articles qualify for this feature.](https://theplosblog.plos.org/2023/07/accessible-data/) ## Abstract ### Background Accurate detection of respiratory viruses relies on appropriate sample collection, but whether joint nose and throat sampling is necessary for high diagnostic performance or whether nose sampling alone can provide comparable results remains uncertain. ### Objectives We evaluated the diagnostic agreement between joint nose and throat swabs (NTS) and Rhinoswab (RhinoMed, Cremorne, Australia), a novel anterior nasal swab for RT-qPCR detection of respiratory viruses among symptomatic outpatients. ### Study design Outpatients with febrile acute respiratory illness were enrolled at a clinic in Hong Kong and paired joint NTS and Rhinoswab samples were tested by reverse transcription polymerase chain reaction (RT-qPCR) for influenza A, influenza B, SARS-CoV-2 and human ribonuclease P (RNase P) as an internal control. Diagnostic agreement and RT-qPCR Ct values were compared between the paired samples. ### Results Between May 2023 and April 2024, 488 participants provided paired samples. Overall concordance between Rhinoswab and NTS was 98.0% (95% CI: 96.3% to 99.0%) for influenza A, 99.0% (95% CI: 97.6% to 99.7%) for influenza B, and 99.0% (95% CI: 97.6% to 99.7%) for SARS-CoV-2. Cohen’s kappa also indicated high agreement for all viruses: 0.95 (95% CI: 0.92 to 0.98) for influenza A, 0.94 (95% CI: 0.88 to 0.99) for influenza B, and 0.92 (95% CI: 0.85 to 0.99) for SARS-CoV-2. Ct values from Rhinoswab were moderately correlated with NTS for all three viruses and RNase P. The majority of discordant samples had Ct values of 30 and above (16/18, 88.9%). ### Conclusions Rhinoswabs achieved high agreement with joint NTS for RT-qPCR detection of influenza and SARS-CoV-2. Given their minimal invasiveness Rhinoswabs are a viable alternative specimen type for supervised respiratory virus testing. ## Figures ![Table 1](https://journals.plos.org/plosone/article/figure/image?size=inline&id=10.1371/journal.pone.0355869.t001) ![Fig 1](https://journals.plos.org/plosone/article/figure/image?size=inline&id=10.1371/journal.pone.0355869.g001) ![Table 1](https://journals.plos.org/plosone/article/figure/image?size=inline&id=10.1371/journal.pone.0355869.t001) ![Fig 1](https://journals.plos.org/plosone/article/figure/image?size=inline&id=10.1371/journal.pone.0355869.g001) ![Table 1](https://journals.plos.org/plosone/article/figure/image?size=inline&id=10.1371/journal.pone.0355869.t001) ![Fig 1](https://journals.plos.org/plosone/article/figure/image?size=inline&id=10.1371/journal.pone.0355869.g001) **Citation:** Murphy C, Cheng SMS, Mak L, So HC, Ip DKM, Peiris M, et al. (2026) Diagnostic agreement between Rhinoswabs and joint nose and throat swabs for the detection of influenza and SARS-CoV-2 among symptomatic ambulatory patients in Hong Kong. PLoS One 21(8): e0355869. https://doi.org/10.1371/journal.pone.0355869 **Editor:** Hin Fung Tsang, Hong Kong Adventist Hospital, CHINA **Received:** April 23, 2026; **Accepted:** July 26, 2026; **Published:** August 11, 2026 **Copyright:** © 2026 Murphy et al. This is an open access article distributed under the terms of the [Creative Commons Attribution License](http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. **Data Availability:** All data and code supporting the findings of this study are fully available without restriction from a public GitHub repository: . **Funding:** This research was financially supported by a grant received by BJC from the Health and Medical Research Fund, Health Bureau, the Government of the Hong Kong Special Administrative Region (grant number INF-HKU-3) and the Theme-based Research Scheme (grant number T11-712/19-N) of the Research Grants Council of the Hong Kong SAR Government. There was no additional external funding received for this study. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. **Competing interests:** BJC consults for AstraZeneca, Fosun Pharma, GSK, Haleon, Moderna, Novavax, Pfizer, Roche, Sanofi Pasteur, and Seqirus. The authors report no other potential conflicts of interest. The Centre for Immunology and Infection provided support in the form of salaries for authors (MP) but did not have any additional role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript. The specific roles of these authors are articulated in the ‘author contributions’ section. There is no relevant commercial interest for C2I. This does not alter our adherence to PLOS ONE policies on sharing data and materials. ## Background Accurate and timely detection of influenza and SARS-CoV-2 is important for surveillance and clinical management. Molecular testing by polymerase chain reaction (PCR) is the gold standard but its accuracy is contingent on the quality of the specimen collected which is influenced by the anatomical site of active viral replication sampled. In Hong Kong, diagnostic testing is typically carried out using nasopharyngeal swabs or joint nose and throat swabs (NTS). In contrast to nasopharyngeal swabbing, which requires deep insertion into the nasal cavity by a trained professional, joint NTS is less invasive and suitable for self-collection. However, an evaluation of the UK COVID-19 National Testing Programme observed a preference for nose-only swabbing compared to joint NTS, reporting it was easier to perform and less uncomfortable [[1](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#pone.0355869.ref001)]. The Rhinoswab™ was developed by RhinoMed (Cremorne, Australia) in 2020 [[2](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#pone.0355869.ref002),[3](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#pone.0355869.ref003)] aiming to be minimally invasive by collecting nasal discharge from the anterior nares. ## Objectives We aimed to estimate the concordance between Rhinoswabs and joint NTS for detecting influenza and SARS-CoV-2 via RT-PCR among symptomatic outpatients in Hong Kong. ## Study design ### Study participants We utilised data from an ongoing outpatient surveillance study in Hong Kong, between 03/05/2023 and 29/04/2024. Eligible patients were aged ≥6 months and were seeking medical care for a febrile acute respiratory illness, defined as the presence of ≥2 respiratory symptoms within 3 days of symptom onset. A questionnaire was administered to collect vaccination history and demographics. The study protocol was approved by the Institutional Review Board of the University of Hong Kong. Written informed consent was obtained from all participants or their legal guardians for minors. The individual pictured in this manuscript has given written informed consent to publish the image. ### Specimen collection and laboratory testing All participants were first sampled using rapid antigen tests (unrelated to this study), followed by a joint NTS (CLASSIQSwabs™, Copan) and then by the Rhinoswab as participants could opt out of being sampled using a Rhinoswab. A demonstration video was shown and a junior version of the Rhinoswab was available for children ([S1 Fig](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#pone.0355869.s001)). For participants that agreed to provide a Rhinoswab sample, collection was performed by study staff according to manufacturers’ instructions. Swabs were inserted into the anterior nares and left for 15 seconds while the participant breathed normally and then moved back and forth in the nostril for an additional 15 seconds. After removal, each loop of the swab was snapped off into the collection tube at predefined break points. All swabs were transported to the laboratory in viral transport media and tested for influenza A, influenza B, and SARS-CoV-2 using a ViiA7 RT-qPCR system (ThermoFisher). RNA extraction and RT-qPCR targets and conditions have been described previously [[4](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#pone.0355869.ref004)]. A cycle threshold (Ct) value of <40 was considered positive. ### Statistical analysis Participants were included if they had paired joint NTS and Rhinoswab samples. Agreement was assessed by estimating concordance, defined as the percentage of paired swabs with identical results (positive or negative) and Cohen’s kappa with 95% confidence intervals (CI). Concordance was also evaluated by age, time since the onset of symptoms and vaccination status (received influenza or COVID-19 vaccination within a year before seeking medical care). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) with 95% confidence intervals are also reported to evaluate the diagnostic performance of the Rhinoswab compared to joint NTS. In addition, the correlation between the Ct values for both swabs was assessed using Pearson’s correlation coefficients. We plotted the difference in Ct values (Rhinoswab minus NTS) against NTS Ct values to assess variability across a range of viral loads. Analyses were performed using R version 4.0.2 (R Foundation for Statistical Computing, Vienna, Austria). ## Results During the study period, 531 participants were enrolled and invited to provide paired samples, of whom 488 (91.9%) provided paired samples, while 43 (8.1%) opted out. Of those that opted out, 16/43 (37.2%) were unwilling after viewing the demonstration video. Of the 488 Rhinoswabs collected, 246 (50.4%) were Rhinoswab junior. The mean age was 25 years and the majority of participants were female (55.5%) ([Table 1](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#pone-0355869-t001)). [![thumbnail](https://journals.plos.org/plosone/article/figure/image?size=inline&id=10.1371/journal.pone.0355869.t001)](https://journals.plos.org/plosone/article/figure/image?size=medium&id=10.1371/journal.pone.0355869.t001 "Click for larger image") Download: * [PNG larger image](https://journals.plos.org/plosone/article/figure/image?download&size=large&id=10.1371/journal.pone.0355869.t001) * [TIFF original image](https://journals.plos.org/plosone/article/figure/image?download&size=original&id=10.1371/journal.pone.0355869.t001) Table 1. Study participant characteristics by virus detected by both Rhinoswab and joint nose-throat swab. [ https://doi.org/10.1371/journal.pone.0355869.t001](https://doi.org/10.1371/journal.pone.0355869.t001) Influenza A was detected in 136 participants by both joint NTS and Rhinoswab, with a concordance of 98.0% (95% CI: 96.3% to 99.0%) and Cohen’s kappa of 0.95 (95% CI: 0.92 to 0.98). There were 42 influenza B and 32 SARS-CoV-2 positives by both swabs respectively ([Table 1](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#pone-0355869-t001)). The concordance for detecting influenza B and SARS-CoV-2 was 99.0% (95% CI: 97.6% to 99.7%) for both viruses, with corresponding Cohen’s kappa values of 0.94 (95% CI: 0.88 to 0.99) and 0.92 (95% CI: 0.85 to 0.99), respectively. Concordance was similar among different age groups, time since onset and vaccination status ([S2 Fig](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#pone.0355869.s002)). The Ct values from Rhinoswabs were significantly positively correlated with those from joint NTS for all three viruses and the internal control, human RNase P ([Fig 1](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#pone-0355869-g001) panels A-D). Correlations coefficients were 0.76 for influenza A, 0.818 for influenza B, and 0.729 for SARS-CoV-2, while human RNase P showed a moderate correlation (r = 0.616). When the difference between Ct values (Rhinoswab minus NTS) was plotted against the NTS Ct value there was no evidence of substantially different Rhinoswab agreement for higher or lower Ct values ([Fig 1](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#pone-0355869-g001) panels E-H). The majority of discordant samples (16/18, 88.9%) had Ct values of ≥30 ([S1 Table](https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0355869#pone.035586
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