Decreased B Cells on Admission Associated With Prolonged Viral RNA Shedding From the Respiratory Tract in Coronavirus Disease 2019: A Case-Control Study.

The viral RNA shedding time (VST) for severe acute respiratory syndrome coronavirus 2 has not been well characterized. Clinical data were collected and compared between patients with short and long VSTs (in the lower and upper quartiles, respectively). The probability of recurrent positive reverse-transcription polymerase chain reaction results decreased sharply to 4.8% after 3 consecutive negative results. A series of ≥3 consecutive negative results was suitable as a criterion for the end of viral RNA shedding. The VST for shedding from the respiratory tract was significantly shorter in patients with normal B-cell counts on admission than in those with decreased B-cell counts (median [interquartile range], 11 [9-13] vs 16 [12-20] days, respectively; P = .001).