Sputum testing is more accurate compared to the swab testing and provided a higher rate of COVID-19 detection, reveals a new study.
Sputum testing was more accurate compared to nasopharyngeal or oropharyngeal swabs for detecting SARS-CoV-2, reports a new study. The findings of the study are published in the journal EBioMedicine.// A sputum culture is a test to detect and identify bacteria or fungi that infect the lungs or breathing passages. Sputum samples are generally collected by having a patient cough deeply to produce and expel phlegm.
‘Sputum testing can detect the RNA of the virus that causes COVID-19 at significantly higher rates than the oropharyngeal swab testing.’
Nasopharyngeal (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 Covid-19 diagnosis. Other approaches to collect specimens -- including from an oropharyngeal swab and sputum -- have been tested in small studies, but there is uncertainty about which method is best for detecting the virus.
"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," said study researcher Jonathan Li from the Brigham and Women's Hospital in the US.
In the study published in the journal EBioMedicine, the research team conducted a systematic review and meta-analysis, analyzing data from more than 3,000 specimens to compare the three approaches.
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.
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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.
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"When it comes to testing, the earlier, the better, as diagnostic accuracy is improved earlier after symptom onset, regardless of the sampling site," said Li.
"Not all patients are able to produce a sputum sample; for such patients, a nasopharyngeal swab may be the best collection method," the authors noted.
Source-IANS