Distinct RT-PCR diagnosis profiles of father and son patients of COVID-19 using nasopharyngeal and alveolar lavage fluid samples

The detection of viral nucleic acid by real time RT-PCR is the main confirmative diagnostic method for COVID-19 in clinical practice in China and worldwide. However, its sensitivity is unclear. Here we report two cases in a family in Guizhou, southwestern China. The father had a history of long stay in Wuhan. Surprisingly, although the son was diagnosed positive using the nasopharyngeal swab specimen and the rRT-PCR method, the father was diagnosed negative continuously for multiple times. Only after the alveolar lavage fluid sample was used, the father’s rRT-PCR diagnosis turned positive. Their CT diagnosis and clinical symptoms did not completely align with their rRT-PCR diagnostic results. The underlying mechanisms and their implications to clinical practice are discussed.