Table 1. Sampling Time Points in Relation to Patient Illness and Clinical Cycle Threshold Values.
| Patient | Days of illness when samples were collected | Presence of symptoms during sampling | Symptoms | Disease severitya | Before/after routine cleaning | Cycle threshold value from clinical samplesb |
|---|---|---|---|---|---|---|
| A | 4, 10 | Yes, both days | Cough, fever, shortness of breath | Moderate | After | 31.31 (day 3); 35.33 (day 9) |
| B | 8, 11 | Yes on day 8; asymptomatic on day 11 | Cough, fever, sputum production | Moderate | After | 32.22 (day 8); not detected (day 11) |
| C | 5 | Yes | Cough | Mild | Before | 25.69 (day 4) |
a
Disease severity was considered moderate if there was lung involvement (opacities on chest radiograph) and severe if patient required supplemental oxygen therapy.
b
Clinical samples were either nasopharyngeal swabs or sputum samples if patient could produce sputum. The most recent result prior to the environmental sampling was recorded. Cycle threshold refers to the number of cycles required for the fluorescent signal to cross the threshold in reverse transcriptase–polymerase chain reaction; a lower cycle threshold value indicates a higher viral load.