Publication
Validation of saliva sampling as an alternative to oro-nasopharyngeal swab for detection of SARS-CoV-2 using unextracted rRT-PCR with the Allplex 2019-nCoV assay
Publisher:
Microbiology Society
Date:
09-08-2021
DOI:
10.1099/JMM.0.001404
Abstract: Introduction. The current severe acute respiratory syndrome-associated coronavirus-2 (SARS-CoV-2) pandemic has stressed the global supply chain for specialized equipment, including flocked swabs. Hypothesis. Saliva could be a potential alternative specimen source for diagnosis of SARS-CoV-2 infection by reverse-transcriptase PCR (RT-PCR). Aim. To compare the detection efficiency of SARS-CoV-2 RNA in saliva and oro-nasopharyngeal swab (ONPS) specimens. Methodology. Patients recruited from hospital provided paired saliva and ONPS specimens. We performed manual or automated RT-PCR with prior proteinase K treatment without RNA extraction using the Seegene Allplex 2019 nCoV assay. Results. Of the 773 specimen pairs, 165 (21.3 %) had at least one positive s le. Additionally, 138 specimens tested positive by both s ling methods. Fifteen and 12 cases were detected only by nasopharyngeal swab and saliva, respectively. The sensitivity of ONPS (153/165 92.7 % 95 % CI: 88.8–96.7) was similar to that of saliva (150/165 90.9 % 95 % CI: 86.5–95.3 P =0.5). In patients with symptoms for ≤ 10 days, the sensitivity of ONPS (118/126 93.7 % 95 % CI: 89.4–97.9) was similar to that of saliva (122/126 96.8 % 95 % CI: 93.8–99.9 % P =0.9). However, the sensitivity of ONPS (20/22 95.2 % 95 % CI: 86.1–100) was higher than that of saliva (16/22 71.4 % 95 % CI: 52.1–90.8) in patients with symptoms for more than 10 days. Conclusions. Saliva s ling is an acceptable alternative to ONPS for diagnosing SARS-CoV-2 infection in symptomatic in iduals displaying symptoms for ≤ 10 days. These results reinforce the need to expand the use of saliva s les, which are self-collected and do not require swabs.