Features Partner Sites Information LinkXpress hp
Sign In
Advertise with Us

Download Mobile App





Sputum Testing Has Significantly Higher COVID-19 Detection Rate than Oropharyngeal Swab Testing

By LabMedica International staff writers
Posted on 27 Jul 2020
Among the three approaches to collecting specimens, including sputum, nasopharyngeal (NP) swabs and oropharyngeal swabs, sputum testing has been found to detect the RNA of the virus that causes COVID-19 at significantly higher rates while oropharyngeal swab testing had lower rates.

NP swabs, which require inserting a long shaft into the nasal cavity to collect a sample from the back of the nose and throat, are currently the gold standard for collecting a specimen for diagnosis. More...
However, the procedure is technically challenging, often uncomfortable for patients and requires personal protective equipment that may be in short supply. Oropharyngeal swabs are collected by inserting a shaft through the mouth; and sputum samples are generally collected by having a patient cough deeply to produce and expel phlegm. Not all patients are able to produce a sputum sample; for such patients, a nasopharyngeal swab may be the best collection method. These approaches to collecting specimens have been tested in small studies, although there is uncertainty about which method is best for detecting the virus.

Investigators from the Brigham and Women’s Hospital (Boston, MA, USA) conducted a systematic review and meta-analysis, analyzing data from more than 3,000 specimens to compare the three approaches. For their study, the researchers scoured the literature, both preprints and published papers, for studies that assessed at least two respiratory sampling sites using an NP swab, oropharyngeal swab or sputum. From more than 1,000 studies, they identified 11 that met their criteria. These studies included results from a total of 3,442 respiratory tract specimens. The team examined how often each collection method produced a positive result.

The team found that sputum testing detected the RNA of the virus that causes COVID-19 at significantly higher rates while oropharyngeal swab testing had lower rates. Regardless of the collection method, the earlier samples were collected after symptoms began, the higher the detection rate. For NP swabs, the rate was 54%; for oropharyngeal swabs, 43%; for sputum, 71%. The rate of viral detection was significantly higher in sputum than either oropharyngeal swabs or NP swabs. Detection rates were highest within one week of symptom onset for all three tests.

“The accurate diagnosis of COVID-19 has implications for health care, return-to-work, infection control and public health,” said corresponding author Jonathan Li, MD, a faculty member in the Division of Infectious Diseases at the Brigham. “Our gold standard in and out of the hospital is the nasopharyngeal swab, but there’s a lot of confusion about which sampling modality is best and most sensitive. Our study shows that sputum testing resulted in significantly higher rates of SARS-CoV-2 detection and supports the use of this type of testing as a valuable method for the diagnosis and monitoring of COVID-19 patients.”

Related Links:
Brigham and Women’s Hospital


Gold Member
SARS‑CoV‑2/Flu A/Flu B/RSV Sample-To-Answer Test
SARS‑CoV‑2/Flu A/Flu B/RSV Cartridge (CE-IVD)
Portable Electronic Pipette
Mini 96
New
Anterior Nasal Specimen Collection Swabs
53-1195-TFS, 53-0100-TFS, 53-0101-TFS, 53-4582-TFS
New
Gram-Negative Blood Culture Assay
LIAISON PLEX Gram-Negative Blood Culture Assay
Read the full article by registering today, it's FREE! It's Free!
Register now for FREE to LabMedica.com and get access to news and events that shape the world of Clinical Laboratory Medicine.
  • Free digital version edition of LabMedica International sent by email on regular basis
  • Free print version of LabMedica International magazine (available only outside USA and Canada).
  • Free and unlimited access to back issues of LabMedica International in digital format
  • Free LabMedica International Newsletter sent every week containing the latest news
  • Free breaking news sent via email
  • Free access to Events Calendar
  • Free access to LinkXpress new product services
  • REGISTRATION IS FREE AND EASY!
Click here to Register








Channels

Hematology

view channel
Image: New research points to protecting blood during radiation therapy (Photo courtesy of 123RF)

Pioneering Model Measures Radiation Exposure in Blood for Precise Cancer Treatments

Scientists have long focused on protecting organs near tumors during radiotherapy, but blood — a vital, circulating tissue — has largely been excluded from dose calculations. Each blood cell passing through... Read more

Immunology

view channel
Image: The VENTANA HER2 (4B5) test is now CE-IVDR approved (Photo courtesy of Roche)

Companion Diagnostic Test Identifies HER2-Ultralow Breast Cancer and Biliary Tract Cancer Patients

Breast cancer is the most common cancer in Europe, with more than 564,000 new cases and 145,000 deaths annually. Metastatic breast cancer is rising in younger populations and remains the leading cause... Read more

Technology

view channel
Image: Conceptual design of the CORAL capsule for microbial sampling in the small intestine (H. Mohammed et al., Device (2025). DOI: 10.1016/j.device.2025.100904)

Coral-Inspired Capsule Samples Hidden Bacteria from Small Intestine

The gut microbiome has been linked to conditions ranging from immune disorders to mental health, yet conventional stool tests often fail to capture bacterial populations in the small intestine.... Read more
Copyright © 2000-2025 Globetech Media. All rights reserved.