Our case series is limited by the small sample size and the lack of molecular confirmation of SARS-CoV-2 infection. However, only 30–50% of infected patients had positive test for SARS-CoV-2 nucleic acid on RT-PCR (Chinese Academy of Sciences; unpublished data). High rates of false-negative findings may be explained by several reasons, including (1) the lack of SOPs for SARS-CoV-2 nucleic acid detection, differences in sample handling, storage, and processing, (2) disease stages and different viral loads according to anatomical site (e.g., alveoli versus upper respiratory tract), (3) the lack of independent validation of current testing, and (4) the potential high mutation rates of COVID-19. In light of these limitations, some cases of COVID-19 in China are currently diagnosed on clinical, laboratory, and imaging grounds, without resorting to molecular confirmation.