Saliva or Nasopharyngeal Swab Specimens for Detection of SARS-CoV-2

Rapid and accurate diagnostic tests are essential for controlling the ongoing Covid-19 pandemic.

Rapid and accurate diagnostic tests are essential for controlling the ongoing Covid-19 pandemic. Although the current standard involves testing of nasopharyngeal swab specimens by quantitative reverse-transcriptase polymerase chain reaction (RT-qPCR) to detect SARS-CoV-2, saliva specimens may be an alternative diagnostic sample. In this paper recently published in the New England Journal of Medicine, the authors compared the sensitivity in detection of SARS-CoV-2 during the course of infection in both saliva specimens and nasopharyngeal swab specimens. A total of 70 inpatients with Covid-19 were included. After Covid-19 was confirmed with a positive nasopharyngeal swab specimen at hospital admission, the authors obtained additional samples from the patients during hospitalisation. Moreover, they tested saliva specimens collected by the patients themselves and nasopharyngeal swabs collected from the patients at the same time point by health care workers. The results of the study suggested that saliva specimens and nasopharyngeal swab specimens have at least similar sensitivity in the detection of SARS-CoV-2 during the course of hospitalisation. The authors concluded that, given the growing need for testing, their findings provide support for the potential of saliva specimens in the diagnosis of SARS-CoV-2 infection.

DOI: 10.1056/NEJMc2016359