Exhaled SARS-CoV-2 RNA viral load kinetics measured by facemask sampling associates with household transmission

摘要: ObjectivesNo studies have examined longitudinal patterns of naturally exhaled SARS-CoV-2 RNA viral load (VL) during acute infection. We report this using facemask sampling (FMS) and assessed the relationship between emitted RNA VL and household transmission.MethodsBetween December 2020 and February 2021, we recruited participants within 24 hours of a positive RT-qPCR on upper respiratory tract sampling (URTS) (day 0). Participants gave FMS (for 1 hour) and URTS (self-taken) on seven occasions up to day 21. Samples were analysed by RT-qPCR (from sampling matrix strips within the mask) and symptom diaries were recorded. Household transmission was assessed through reporting of positive URTS RT-qPCR in household contacts.ResultsAnalysis of 203 FMS and 190 URTS from 34 participants showed that RNA VL peaked within the first 5 days following sampling. Concomitant URTS, FMS …