Case presentations

In five cases, oropharyngeal swabs and sputum samples were obtained simultaneously on every other day, and staring the Ct values . In total, there were 40 testing points with detectable virus before the four patients were de-quarantined (after two consecutive tests with Ct values of 40), and the data showed that viral loads of detecting SARS CoV-2 in sputum was higher. At 67.5% (27/40) of the testing time points, the ratio of the Ct value for sputum to the Ct value of the oropharyngeal swab was less than or equal to one, indicating higher viral loads of detection in sputum, compared to 32.5% (13/40) for oropharyngeal swabs. Therefore, the viral loads of sputum detection is speculated to be higher than the viral loads of oropharyngeal swab detection.

In cases 1 to 5, the mean Ct values of the initial sputum samples, collected on illness days 1-3, were 17, 25, 30, 19, and 31 respectively, which increased to 19, 35, 33, 29, and 40 respectively, in samples collected on illness days 8-10. LPV/r was administered to case 1 on illness days 5-8 and to case 2 on illness days 2-14, and an increase of Ct values between these two time points was 0.9 per day in case 1

and 2, compared to an increase of 1.0 per day between these time points in case 3, 4 and 5 which were not administered LPV/r.

This analysis of five cases of COVID-19 in Taiwan showed that SARS CoV-2 detection in sputum specimens was more sensitive than detection in oropharyngeal swabs, as 67.5% of the Ct value ratios of sputum to oropharyngeal swabs were less than or equal to one. Therefore, the viral loads of sputum detection is speculated to be higher than that of oropharyngeal swab detection. In addition, an increase of Ct values between these two time points was 0.9 per day in case 1 and 2, compared to an increase of 1.0 per day in the non-LPV/r-treated cases (3, 4 and 5); therefore, we concluded that LPV/r did not shorten the duration of SARS CoV-2 viral shedding in patients with mild pneumonia.No effective medical treatment against SARS CoV-2 infection has been identified. Ribavirin is a synthetic nucleoside antiviral agent that has been widely used in SARS epidemics. However, various studies have shown no definitive effectiveness and serious toxicities.6 Until now, no data have been published on the use of ribavirin for SARS CoV-2 infection.

In conclusion, LPV/r may not be recommended for COVID-19 patients with mild pneumonia, and additional medications should be studied in scaled-up observation studies.