Fig. 3: Reported case severity, including proportion of asymptomatic, mild, moderate and severe of critical for COVID-19 for index cases and secondary cases, and their corresponding risk ratio of index cases verse secondary cases.
From: Using secondary cases to characterize the severity of an emerging or re-emerging infection

Red circles and lines indicate the proportion of fever of index cases and the corresponding 95% exact binomial confidence intervals. Blue triangles and lines indicate the proportion of fever of secondary cases and the corresponding 95% confidence intervals. Black squares and lines indicate the risk ratio of proportion of fever of index cases compared with secondary cases and the corresponding 95% confidence intervals calculated based on normal approximation. All statistical tests are two-sided tests. Adjustments are not made for multiple comparisons.