Figure 1.

Longitudinal quantitative RT-PCR severe acute respiratory syndrome coronavirus 2 test results for patients diagnosed with coronavirus disease 2019. A: Test results for three representative patients (P1, P2, and P3). The day of diagnosis and the last positive test result (purple) demarcate the “positive period” (light blue shading). Negative test results within this individually determined period were regarded as “undetectable” (orange). Similarly, positive test results within the positive period were regarded as detectable (blue). All test series end with a sequence of one or more negative results (red). B: Longitudinal severe acute respiratory syndrome coronavirus 2 test results for the study population (Table 1). [For clarity, 191 patients for whom the first negative sample (red) was obtained >50 days after the day of diagnosis were omitted.] Patients are sorted according to the dates, relative to diagnosis, of their first negative result, then by the relative date of the last positive result. C: Frequency of test results per day relative to diagnosis.