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Diagnostic performance of different sampling approaches for SARS-CoV-2 RT-PCR testing: a systematic review and
Nicole Ngai Yung Tsang1, Hau Chi So1, Ka Yan Ng1
1WHO Collaborating Centre for Infectious Disease Epidemiology and Control, School of Public Health, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong Special Administrative Region, China.
The Lancet. Infectious Diseases
|April 15, 2021
Summary
Pooled nasal and throat swabs demonstrate superior diagnostic performance for SARS-CoV-2 compared to other methods. Saliva and nasal swabs are acceptable alternatives, while throat swabs are not recommended for accurate diagnosis.
Area of Science:
- Infectious Diseases
- Diagnostic Medicine
- Public Health
Background:
- The optimal clinical sampling method for diagnosing SARS-CoV-2 (Severe Acute Respiratory Syndrome Coronavirus 2) via RT-PCR remains unclear.
- This meta-analysis systematically compares the diagnostic performance of various respiratory specimen collection methods in ambulatory care settings.
Purpose of the Study:
- To systematically review and compare the diagnostic accuracy of different clinical specimen collection methods for SARS-CoV-2 detection.
- To identify the most effective sampling strategies for RT-PCR-based diagnosis in patients with suspected infection.
Main Methods:
- A systematic search of multiple databases (PubMed, Embase, etc.) was conducted for studies published between January 2000 and November 2020.
- Included were original clinical studies evaluating nasopharyngeal swabs and other respiratory specimens for SARS-CoV-2 diagnosis in ambulatory care.
- Diagnostic performance metrics (sensitivity, specificity, PPV, NPV) were analyzed using random effects models.
Main Results:
- Pooled nasal and throat swabs exhibited the highest sensitivity (97%) and positive predictive value (97%) compared to nasopharyngeal swabs (gold standard).
- Saliva (85% sensitivity) and nasal swabs (86% sensitivity) showed comparable, good diagnostic performance.
- Throat swabs demonstrated significantly lower sensitivity (68%) and positive predictive value (75%), making them less suitable for diagnosis.
Conclusions:
- Pooled nasal and throat swabs are the most effective alternative sampling method for SARS-CoV-2 diagnosis in ambulatory settings.
- Saliva and nasal swabs are clinically acceptable alternatives with good diagnostic performance.
- Throat swabs are not recommended due to their low sensitivity and positive predictive value.
