Comparison of saliva with healthcare workers- and patient-collected swabs in the diagnosis of COVID-19 in a large cohort

BMC Infectious Diseases

Anand Gupta¹  Sarala Kumari Daram¹  Naveen Chander Reddy Podduturi¹  Duvvur Nageshwar Reddy²  Yelamanchili Sadhana³  Ketavarapu Vijayasarathy⁴  Mitnala Sasikala⁴ 

[1] Department of Critical Care Medicine, AIG Hospitals, Survey No 136, Plot No 2/3/4/5, 1, Mindspace Road, Gachibowli, 500032, Hyderabad, Telangana, India;Department of Medical Gastroenterology, AIG Hospitals, Survey No 136, Plot No 2/3/4/5, 1, Mindspace Road, Gachibowli, 500032, Hyderabad, Telangana, India;Department of Microbiology, AIG Hospitals, Survey No 136, Plot No 2/3/4/5, 1, Mindspace Road, Gachibowli, 500032, Hyderabad, Telangana, India;Department of Molecular Biology, Institute of Translational Research, Asian Healthcare Foundation, AIG Hospitals, Survey No 136, Plot No 2/3/4/5, 1, Mindspace Road, Gachibowli, 500032, Hyderabad, Telangana, India;

关键词: SARS-COV-2;    Saliva;    Healthcare worker;    Nasopharyngeal swab;   

DOI  :  10.1186/s12879-021-06343-w

来源: Springer

【 摘 要 】

BackgroundA considerable amount of evidence demonstrates the potential of saliva in the diagnosis of COVID-19. Our aim was to determine the sensitivity of saliva versus swabs collected by healthcare workers (HCWs) and patients themselves to assess whether saliva detection can be offered as a cost-effective, risk-free method of SARS-CoV-2 detection.MethodsThis study was conducted in a hospital involving outpatients and hospitalized patients. A total of 3018 outpatients were tested. Of these, 200 qRT-PCR-confirmed SARS-CoV-2-positive patients were recruited for further study. In addition, 101 SARS-CoV-2-positive hospitalized patients with symptoms were also enrolled in the study. From outpatients, HCWs collected nasopharyngeal swabs (NPS), saliva were obtained. From inpatients, HCWs collected swabs, patient-collected swabs, and saliva were obtained. qRT-PCR was performed to detect SARS-CoV-2 by TAQPATH assay to determine the sensitivity of saliva detection. Sensitivity, specificity and positive/negative predictive values (PPV, NPV) of detecting SARS-CoV-2 were calculated using MedCalc.ResultsOf 3018 outpatients (asymptomatic: 2683, symptomatic: 335) tested by qRT-PCR, 200 were positive (males: 140, females: 60; aged 37.9 ± 12.8 years; (81 asymptomatic, 119 symptomatic). Of these, saliva was positive in 128 (64%); 39 of 81 asymptomatic (47%),89 of 119 symptomatic patients (74.8%). Sensitivity of detection was 60.9% (55.4–66.3%, CI 95%), with a negative predictive value of 36%(32.9–39.2%, CI 95%).Among 101 hospitalized patients (males:65, females: 36; aged 53.48 ± 15.6 years), with HCW collected NPS as comparator, sensitivity of saliva was 56.1% (47.5–64.5, CI 95%), specificity 63.5%(50.4–75.3, CI95%) with PPV of 77.2% and NPV of 39.6% and that of self-swab was 52.3%(44–60.5%, CI95%), specificity 56.6% (42.3–70.2%, CI95%) with PPV 77.2% and NPV29.7%. Comparison of positivity with the onset of symptoms revealed highest detection in saliva on day 3 after onset of symptoms. Additionally, only saliva was positive in 13 (12.8%) hospitalized patients.ConclusionSaliva which is easier to collect than nasopharyngeal swab is a viable alternate to detect SARS-COV-2 in symptomatic patients in the early stage of onset of symptoms. Although saliva is currently not recommended for screening asymptomatic patients, optimization of collection and uniform timing of sampling might improve the sensitivity enabling its use as a screening tool at community level.

【 授权许可】

CC BY