Saliva as a Biological Fluid in SARS-CoV-2 Detection

Area of Science:

• Virology
• Infectious Diseases
• Diagnostic Methods

Background:

• Polymerase chain reaction (PCR) of nasopharyngeal swabs was the gold standard for SARS-CoV-2 diagnosis during the COVID-19 pandemic.
• Saliva collection emerged as a promising alternative for sample acquisition.
• This study aimed to compare saliva and nasopharyngeal swab (NPS) efficacy in SARS-CoV-2 detection.

Purpose of the Study:

• To compare the qualitative and quantitative detection of SARS-CoV-2 using saliva versus NPS samples.
• To determine the detection limits for both sample collection methods.
• To assess the financial costs and sustainability of saliva collection compared to NPS.

Main Methods:

• Evaluated 99 paired saliva and NPS samples for qualitative SARS-CoV-2 detection.
• Performed quantitative comparison of viral particles and determined detection limits.
• Compared cycle threshold (C_T) values, vaccination status, and financial costs.

Main Results:

• Qualitative diagnostic equivalence was observed between saliva and swab collection (96.96%).
• Detection limits were equivalent for both methods, though quantitative agreement was low.
• No significant association between C_T values and vaccination status was found.
• Saliva collection demonstrated lower financial costs and reduced plastic material usage, indicating greater sustainability.

Conclusions:

• Saliva collection is a feasible and sustainable alternative for COVID-19 diagnosis.
• Findings support the adoption of saliva-based testing for SARS-CoV-2 detection.