Statistical analysis
All patients having a result available for the 3 tests were included in the study analysis population. Statistical analyses were conducted using Stata IC 15 (Stata Corp., College Station, Texas, USA) and R statistical software v.4.0.2 (Vienna Austria). Detection rate, sensitivity, and specificity of each test with 95% confidence intervals (CIs) were estimated using standard descriptive methods and subsequently compared using Pearson proportion test for unpaired data, and pairwise proportion tests for paired data. The McNemar test was used to compare PCR and RDT test status (saliva PCR vs NP PCR test status, RDT vs NP PCR test status; paired comparisons). Analyses were stratified by viral load categories. The thresholds chosen for binary stratified analyses by VL were 10