1. Sensitivity of SARS-CoV-2 RNA polymerase chain reaction using a clinical and radiological reference standard
- Author
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Muhammad S Ahmed, Diana Penha, Sheetal Sharma, Cairine Probert, Michael Beadsworth, Catriona Farrell, Katharine E. Stott, Meng-San Wu, Elizabeth Joekes, Rory Hicks, David A Barr, Beth Hankinson, Stacy Todd, James Cruise, Kathryn Haigh, Tamsin Paterson, Fred Fyles, Vijay Chindambaram, Nuria Santamaria, Alice Maxwell, Michael Abouyannis, Alexander J. Stockdale, Nick Moody, Rashika Fernando, Joseph M. Lewis, Imogen Fordham, and Rebecca Wiles
- Subjects
0301 basic medicine ,Microbiology (medical) ,medicine.medical_specialty ,Diagnostic X-Ray ,030106 microbiology ,Diagnostic Testing ,Sensitivity and Specificity ,Polymerase Chain Reaction ,Asymptomatic ,Article ,03 medical and health sciences ,0302 clinical medicine ,Internal medicine ,Epidemiology ,medicine ,Humans ,Infection control ,030212 general & internal medicine ,Medical diagnosis ,Diagnostic Tests, Routine ,SARS-CoV-2 ,business.industry ,COVID-19 ,Odds ratio ,Reference Standards ,Confidence interval ,Infectious Diseases ,Real-time polymerase chain reaction ,Radiological weapon ,RNA, Viral ,medicine.symptom ,Radiology ,business ,SARS-CoV-2, COVID-19, Real-Time Polymerase Chain Reaction - Abstract
Objectives Diagnostic tests for SARS-CoV-2 are important for epidemiology, clinical management, and infection control. Limitations of oro-nasopharyngeal real-time PCR sensitivity have been described based on comparisons of single tests with repeated sampling. We assessed SARS-CoV-2 PCR clinical sensitivity using a clinical and radiological reference standard. Methods Between March-May 2020, 2060 patients underwent thoracic imaging and SARS-CoV-2 PCR testing. Imaging was independently double- or triple-reported (if discordance) by blinded radiologists according to radiological criteria for COVID-19. We excluded asymptomatic patients and those with alternative diagnoses that could explain imaging findings. Associations with PCR-positivity were assessed with binomial logistic regression. Results 901 patients had possible/probable imaging features and clinical symptoms of COVID-19 and 429 patients met the clinical and radiological reference case definition. SARS-CoV-2 PCR sensitivity was 68% (95% confidence interval 64–73), was highest 7-8 days after symptom onset (78% (68–88)) and was lower among current smokers (adjusted odds ratio 0.23 (0.12–0.42) p Conclusions In patients with clinical and imaging features of COVID-19, PCR test sensitivity was 68%, and was lower among smokers; a finding that could explain observations of lower disease incidence and that warrants further validation. PCR tests should be interpreted considering imaging, symptom duration and smoking status.
- Published
- 2021