Heat inactivation of SARS-CoV 2 enabled the measurement of salivary cortisol during COVID-19 pandemic

Background and aimSalivary cortisol has become an essential tool in the management of cortisol-related disease. In 2020 the sudden outbreak of COVID-19 pandemic caused several concerns about the use of saliva, due to the risk of contamination, and a European consensus further discourage using salivary cortisol. To decrease infectious risk, we handled specimens by applying a heat treatment to inactivate viral particles, further evaluating the impact of the COVID-19 pandemic on the use of salivary cortisol in clinical practice.Material and methodsSaliva samples were exposed for 10 min at 70 degrees C, then cortisol was measured using LC-MS/MS. The number of salivary cortisol examinations from 2013 to 2022 was extracted from the local electronic database: those performed in 2019, 2020, and 2021 were analyzed and compared with the historical data.ResultsDuring 2020 we observed a decrease of 408 (-20%) examinations (p = 0.05) compared to 2019; especially in salivary cortisol daily rhythm and salivary cortisol/cortisone ratio (respectively reduction of 47% and 88%, p = 0.003 and p = 0.001). Analyzing year 2021 compared with 2020 we reported an increase of 420 examinations (+20%, p = 0.01), with a complete recovery of salivary cortisol measurement (considering 2019: p = 0.71). Major differences were observed between morning salivary cortisol (-20%, p = 0.017), LNSC (-21%, p = 0.012) and salivary cortisol rhythm (-22%, p = 0.056). No Sars-Cov2 infections related to working exposure were reported among laboratory's employers.ConclusionsWe speculate that the adoption of an appropriate technique to inactivate viral particles in saliva specimens allowed the safety maintenance of salivary collections, also during the Sars-CoV-2 outbreak.