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Disease/health condition -
Coronavirus disease (COVID-19)
SARS-CoV-2 nucleic acid amplification test
Assay format
NAAT
Information History
First added in 2020
Purpose type
Diagnosis, Surveillance
Purpose
To diagnose infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in symptomatic and asymptomatic individuals suspected of having been exposed to the virus. For surveillance and confirmation of outbreaks.
Specimen types
Nasopharyngeal swab, Oropharyngeal swab, Bronchoalveolar lavage
WHO prequalified or recommended products
N/A
GMDN
64747
SARS-CoV-2 nucleic acid IVD, kit, nucleic acid technique (NAT)
A collection of reagents and other associated materials intended to be used for the qualitative and/or quantitative detection of nucleic acid from severe acute respiratory syndrome-associated coronavirus 2 (SARS-CoV-2) in a clinical specimen, using a nucleic acid technique (NAT). This test is used to aid the diagnosis of coronavirus disease (COVID-19) infection.
The medical device term(s), code(s) and definition(s) in this section were retrieved from databases external to WHO. As there might be more than one name, definition and “Nomenclature Code” related to the specific medical device, please consult https://gmdnagency.org GMDN ®. © GMDN Agency 2005-2024EMDN
W0105040519
CORONAVIRUS - NA REAGENTS
The code(s) and term(s) in this section were observed and retrieved from public databases and have not been validated by health regulatory authorities. Please consult your regulatory agency and EMDN site: https://webgate.ec.europa.eu/dyna2/emdnWHO supporting publications
World Health Organization. (2020). Priority medical devices list for the COVID-19 response and associated technical specifications: interim guidance, 19 November 2020. World Health Organization. https://iris.who.int/handle/10665/336745 ; World Health Organization. (2020). Diagnostic testing for SARS-CoV-2: interim guidance, 11 September 2020. World Health Organization. https://iris.who.int/handle/10665/334254
Technical specifications
N/A
Related Medical Devices in MeDevIS
SAGE IVD recommended including the SARS-CoV-2 NAT category in the third EDL:
• as a disease-specific IVD for use in clinical laboratories (EDL 3, Section II.b);
• using a nucleic acid test format;
• to diagnose infection by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in symptomatic and asymptomatic individuals suspected of having been exposed to the virus and for surveillance and confirmation of outbreaks. The group requested the addition of a note to the test category entry in the EDL stating the listing was based on evidence for RT-PCR tests and other types of nucleic acid amplification require more evidence and should be subject to further review.
• as a disease-specific IVD for use in clinical laboratories (EDL 3, Section II.b);
• using a nucleic acid test format;
• to diagnose infection by Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in symptomatic and asymptomatic individuals suspected of having been exposed to the virus and for surveillance and confirmation of outbreaks. The group requested the addition of a note to the test category entry in the EDL stating the listing was based on evidence for RT-PCR tests and other types of nucleic acid amplification require more evidence and should be subject to further review.
Given the seriousness of the global SARS CoV-2 pandemic the SAGE IVD recommended listing a NAT for the diagnosis of SARS CoV-2 infection. Although the evidence was preliminary at the time of submission, SAGE IVD recognized the need to make a SARS CoV-2 NAT available and its role as an essential tool in managing the pandemic. NAT remains the assay of choice for diagnosing infection according to international guidelines.
Although most of the evidence provided was collected for RT-PCR tests, SAGE IVD decided to list the assay format as a NAT, thereby allowing countries to consider other types of amplification – such as transcription-mediated amplification – for selection and procurement based on local quality assessment.
In considering the use of POC NATs, SAGE IVD raised some concerns about the lack of evidence available at the time of discussion. SAGE IVD highlighted the rapid advance in evidence generation for SARS CoV-2 testing and recommended this listing be reviewed as and when additional evidence is published.
Many studies have shown that RT-PCR testing has high analytical sensitivity for detecting SARS-CoV-2 viral infection. Because the swabbing process and late swabbing may miss the virus, clinical sensitivity may be lower than the analytical sensitivity, as has been demonstrated in studies which used repeat swabs in those who were initially RT-PCR negative. Because the possibility of false negatives in those with symptoms or known exposure cannot be ruled out, repeated RT-PCR tests should be considered.
Although clinical specificity has been shown to be exceptionally high, no data on specificity were presented in the submission. However, it may be possible to extract relevant data from large COVID-19 prevalence studies, such as the Real Time Assessment of Community Transmission (REACT)* in the United Kingdom, as the false positive rate must be less than the total positive rate. These data suggest a specificity of 99.85%. *Real-time assessment of community transmission findings. In: Imperial College London, Faculty of Medicine, Research and impact [website]. London: Imperial College; 2020. Available at: https://www.imperial.ac.uk/medicine/research-and-impact/groups/react-study/real-time-assessment-of-community-transmission-findings/
World Health Organization. (2021). The selection and use of essential in vitro diagnostics: report of the third meeting of the WHO Strategic Advisory Group of Experts on In Vitro Diagnostics, 2020 (including the third WHO model list of essential in vitro diagnostics). World Health Organization. https://iris.who.int/handle/10665/339064