Since December, 2019, an outbreak of pneumonia caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has led to a serious epidemic in China and other countries, resulting in worldwide concern.1 Family clusters of infected individuals have been reported, and this phenomenon could present a serious threat to public health if not strictly controlled. In a previously reported family cluster, most infected individuals had clinical symptoms, decreased lymphocyte counts, and abnormal chest CT images, and were positive for the virus on quantitative RT-PCR (qRT-PCR) analysis.