Smartphone screen testing, a novel pre-diagnostic method to identify SARS-CoV-2 infectious individuals

Young, Rodrigo M; Solis, Camila J; Barriga-Fehrman, Andres; Abogabir, Carlos; Thadani, Alvaro R; Labarca, Mariana; Bustamante, Eva; Tapia, Cecilia V; Sarda, Antonia G; Sepulveda, Francisca; Pozas, Nadia; Cerpa, Leslie C; Lavanderos, María A; Varela, Nelson M; Santibañez, Alvaro; Sandino, Ana M; Reyes-Lopez, Felipe; Dixon, Garth; Quiñones, Luis A

The COVID-19 pandemic will likely take years to control globally, and constant epidemic surveillance will be required to limit the spread of SARS-CoV-2, especially considering the emergence of new variants that could hamper the effect of vaccination efforts. We developed a simple and robust – Phone Screen Testing (PoST) – method to detect SARS-CoV-2-positive individuals by RT-PCR testing of smartphone screen swab samples. We show that 81.3–100% of individuals with high-viral-load SARS-CoV-2 nasopharyngeal-positive samples also test positive for PoST, suggesting this method is effective in identifying COVID-19 contagious individuals. Furthermore, we successfully identified polymorphisms associated with SARS-CoV-2 Alpha, Beta, and Gamma variants, in SARS-CoV-2-positive PoST samples. Overall, we report that PoST is a new non-invasive, cost-effective, and easy-to-implement smartphone-based smart alternative for SARS-CoV-2 testing, which could help to contain COVID-19 outbreaks and identification of variants of concern in the years to come.