Some laboratory abnormalities in our case, such as elevated CRP, LDH, ALT and AST, were also observed in influenza virus pandemic. Lymphopenia has been considered as a poor prognostic factor for severe hospitalized influenza (H1N1) pandemic 2009, as well as severe acute respiratory syndrome (SARS). These findings may explain common biomarker presentation in viral pneumonia, including COVID-19. The quarantine period for potentially COVID-19 infected individuals was challenging by our case’s laboratory results, her sputum specimens remained positive for SARS-CoV-2 on day 15 and turned negative on day 17 of illness.

Similar to viral pneumonia due to other etiologies, ground-glass opacities (GGOs) are the main CT findings of the patients with COVID-19. Reticular and/or interlobular septal thickening, and consolidation are common associated findings. Crazy-paving pattern was also detected in some cases. Pure consolidation without GGO is less common. These lesions usually involve bilateral lungs. Peripheral distribution of disease was noted in 33% and 85% of patients, respectively. However, normal scan at the early stage of COVID-19 can be found in a few patients when the disease is diagnosed.

As the NCP progresses, increasing size and density of these GGOs or crazy paving pattern were reported. On the contrary, the GGOs will decrease in size and the consolidations, if present, will decrease in density when patients gradually recover. Fibrotic change may be left as a sequela after recovery as was seen in patients recovering from SARS.

Our case demonstrated a typical NCP without progression to ARDS. The worst status of her pneumonia was on illness day 17 and then gradually resolved. Given the negative rRT-PCR of SARS-CoV-2 on illness day 21 and 23, there were persistent milder bilateral lung opacities on the chest radiograph on illness day 25 which were corresponding to bilateral ill-defined GGO patches with or without reticulation, and mild fibrotic change on CT two days later. Chest CT might be a tool to assist diagnosis accompanying with symptoms and traveling history, because the chest radiograph could be normal in those patients with mild or no symptoms.

In summary, our case revealed a natural course of NCP with self-recovery. Rapid diagnostic assays, effective treatment and wide use of chest CT will be crucial to contain the worldwide outbreak of COVID-19 in the future.