Fig 1.
Study flowchart.
Table 1.
Characteristics of participants in the overall and longitudinal cohorts.
Table 2.
Characteristics of participants in the overall analysis cohort by days from symptom onset.
Fig 2.
SARS-CoV-2 longevity in overall analysis cohort saliva and nasal specimens.
(A) Ct values, (B) percent of Ct values under 30 and (C) number of positive and negative test results for saliva direct and nasal VTM specimens over days from symptom onset for the overall cohort (N = 96).
Table 3.
Median Ct values of nasal and saliva specimens stratified by days from symptom onset, and results from the Wilcoxon signed-rank tests for the overall analysis cohort.
Fig 3.
SARS-CoV-2 longevity in overall analysis cohort saliva and nasopharyngeal (NP) specimens.
(A) Ct values, (B) percent of Ct values under 30 and (C) number of positive and negative test results for saliva direct and NP VTM specimens by days since symptom onset for all participants in the overall cohort with both saliva and NP at baseline (n = 53).
Fig 4.
Controlling for media type and volume differences.
SARS-CoV-2 longevity in saliva versus nasal specimens in eNAT media, by (A) Ct values, (B) percent of Ct values under 30 and (C) number of positive and negative test results for saliva and nasal swabs over days since symptom onset (n = 80 observations from 45 patients). SARS-CoV-2 longevity in saliva swabbed in VTM media versus nasal swabs in VTM media, by (D) Ct values, (E) percent of Ct values under 30 and (F) number of positive and negative test results for saliva and nasal specimens over time intervals in days since symptom onset (n = 134 observations from 86 patients). Comparisons of medians within each timespan were performed using the Wilcoxon signed-rank test and comparisons of proportions between specimen types within each timespan were performed using the McNemar test for correlated proportions.
Fig 5.
Sub-analysis of SARS-CoV-2 longevity by age, sex, and oxygen requirements.
Sub-analysis of Ct values by days since symptom onset for saliva (blue) and nasal (orange) specimens among the overall analysis cohort based on (A) age, (B) sex, and (C) need for oxygen support.
Fig 6.
SARS-CoV-2 longevity in longitudinal cohort saliva and nasal specimens.
Analysis of paired specimens in the longitudinal analysis cohort (N = 79 paired observations from 28 patients) by (A) Spaghetti plot of longitudinal Ct values for saliva direct and nasal VTM specimens plotted over time in days since symptom onset. Lines indicate specimens from the same patient. (B) Analysis of paired samples in the longitudinal analysis cohort by patient, (B) Ct values, (C) percent of Ct values under 30, and (D) number of positive and negative test results for saliva direct and nasal VTM specimens by days since symptom onset.
Fig 7.
SARS-CoV-2 survival curve in longitudinal cohort saliva and nasal specimens.
Kaplan-Meier estimate of probability of a positive test for SARS-CoV-2 in saliva direct and nasal VTM specimens over time in days since symptom onset for the longitudinal cohort. Dashed lines indicate median survival times.