Distribution of Transmission Potential During Nonsevere COVID-19 Illness shrestha2020distribution

This study evaluated the transmission potential of COVID-19 by examining viral load over time. Over six weeks, 230 healthcare personnel underwent 528 tests at the Cleveland Clinic. Cycle threshold (Ct) values were obtained using RT-PCR targeting the N gene, and viral loads were calculated. Data were obtained from the combined dataset in the supplementary materials of Challenger et al. BMC Medicine (2022) 20:25 (https://doi.org/10.1186/s12916-021-02220-0).

Analytes

swab_SARSCoV2_N

Cycle threshold (Ct) values were quantified using RT-PCR targeting the N gene in nasopharyngeal swab samples. Ct values were then converted into copies per mL. Viral load calculations were based on the minimum detectable viral load (MDVL) and Ct values. Using commercially available plasmids that contained the nucleocapsid (N) gene, the LOD was found to be 20 copies per uL for upper respiratory specimens. We cannot determine the LOD for raw samples.

Biomarker: SARS-CoV-2
Specimen: nasopharyngeal swab
Units: gc/mL
Gene target: N
Participants: 230
Negative samples: 119
Positive samples (not quantifiable): 0
Quantifiable samples: 409
Limit of quantification: unknown
Limit of detection: unknown