Saliva Testing is a Robust Non-Invasive Method for SARS-CoV-2 RNA Detection

Area of Science:

• Virology
• Diagnostic Medicine
• Public Health

Background:

• Accurate diagnostic testing is crucial for managing the coronavirus pandemic.
• Nasopharyngeal (NP) swabs are the current gold standard for SARS-CoV-2 detection.
• SARS-CoV-2 RNA can be detected in various bodily fluids beyond NP swabs.

Purpose of the Study:

• To compare the efficacy of saliva samples versus NP swabs for detecting SARS-CoV-2 RNA.
• To evaluate the concordance, Ct value variation, and internal control performance between saliva and NP swab samples.

Main Methods:

• 111 individuals (58 COVID-19 patients, 53 healthy volunteers) were enrolled.
• SARS-CoV-2 RNA detection was performed using RT-qPCR kits for both sample types.
• Saliva samples were analyzed using a laboratory-developed kit (Diagnolita) and compared with NP swab results.

Main Results:

• High concordance was observed between saliva and NP swab samples, with positive percent agreement of 98.28% and negative percent agreement of 98.11%.
• A statistically significant, moderately strong correlation (R = 0.53) was found between Ct values from saliva and NP swabs.
• Saliva samples demonstrated more robust performance with lower Ct variation for the internal control (ribonuclease P mRNA).

Conclusions:

• Saliva testing is a robust and reliable non-invasive alternative to NP swabs for SARS-CoV-2 RNA detection.
• Saliva-based testing presents a promising tool for effective COVID-19 screening and diagnosis.