Performance of At-Home Self-Collected Saliva and Nasal-Oropharyngeal Swabs in the Surveillance of COVID-19

SARS-CoV-2 quickly spread in the worldwide population by contact with oral and respiratory secretions of infected individuals, imposing social restrictions to control the infection. Massive testing is essential to breaking the chain of COVID-19 transmission. The aim of this study was to compare the performance of at-home self-collected samples - saliva and combined nasal-oropharyngeal swabs (NOP) - for SARS-CoV-2 detection in a telemedicine platform for COVID-19 surveillance. We analyzed 201 patients who met the criteria of suspected COVID-19. NOP sampling were combined (nostrils and oropharynx) and saliva collected using a cotton pad device. Detection of SARS-COV-2 was performed by using the Altona RealStar SARS-CoV-2 RT-PCR Kit 1.0. According to our data, there was an overall significant agreement (k coefficient value of 0.58) between the performances of saliva and NOP. Assuming that positive results in either sample represent true infections, 70 patients positive for SARS-CoV-2 were identified, with 52/70 being positive in NOP and 55/70 in saliva. This corresponds to sensitivities of 74.2% (95% CI; 63.7% to 83.1%) for NOP and 78.6% (95% CI; 67.6% to 86.6%) for saliva. We also found a strong correlation (Beta coefficients