Testing of sputum is a more accurate way of diagnosing coronavirus disease (Covid-19), according to latest research.
The survey shows sputum was more accurate than nasopharyngeal or oropharyngeal swabs. The study also shows early testing increases rate of Covid-19 diagnosis.
Sputum is a mixture of saliva and mucus coughed up from the respiratory tract, mainly as a result of infection.
The study titled SARS-CoV-2 Detection in Different Respiratory Sites: a Systematic Review and Meta-Analysis which was published last week in EBioMedicine shows early and accurate detection is critical for preventing the spread of Covid-19 and providing appropriate care for patients.
The research noted that 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 standard procedure for collecting specimen for diagnosis.
“But the procedure is technically challenging, often uncomfortable for patients and requires personal protective equipment that may be in short supply.
“Other approaches to collecting specimens, including from an oropharyngeal swab and sputum have been tested in small studies,” said corresponding author Jonathan Li, a faculty member in the Division of Infectious Diseases at the Brigham.
In the new study, researchers from Brigham and Women’s Hospital conducted a systematic review and meta-analysis, analysing data from more than 3,000 specimens to compare the three approaches.
The team found that sputum testing detected the ribonucleic acid (RNA) of the virus that causes Covid-19 at significantly higher rates while oropharyngeal swab testing had lower rates.
They found out that regardless of the collection method, the earlier samples were collected after symptoms began, the higher the detection rate.
“The accurate diagnosis of Covid-19 has implications for health care, return-to-work, infection control and public health,” said Li.
The study shows that sputum testing resulted in significantly higher rates of detection and supports the use of this type of testing as a valuable method for the diagnosis and monitoring of Covid-19 patients.
Li and his colleagues 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. [Protus Onyango]