Saliva Testing Is Accurate for Early-Stage and Presymptomatic COVID-19
Abigail J. Johnson, Shannon Zhou, Suzie Hoops, Benjamin Hillmann, Matthew Schomaker, Robyn Kincaid, Jerry Daniel, Kenneth B. Beckman, Daryl M. Gohl, Sophia Yohe, Dan Knights, Andrew C. Nelson
Abstract
Methods for COVID-19 detection are necessary for public health efforts to monitor the spread of disease. Nasopharyngeal samples have been considered the best approach for COVID-19 testing. However, alternative samples like self-collected saliva offer advantages for population-scale screening. Meta-analyses of recent studies suggest that saliva is useful for detecting SARS-CoV-2; however, differences in disease prevalence, sample collection, and analysis methods still confound strong conclusions on the utility of saliva compared to nasopharyngeal samples. Here, we find that the sensitivity of saliva testing is related to both the timing of the sample collection relative to symptom onset and the disease stage. Importantly, several clinical vignettes in our cohorts highlight the challenges of medical decision making with limited knowledge of the associations between laboratory test data and the natural biology of infection.