Epidemiological parameters of coronavirus disease 2019: a pooled analysis of publicly reported individual data of 1155 cases from seven countries

Shujuan Ma; Jiayue Zhang; Minyan Zeng; Qingping Yun; Wei Guo; Yixiang Zheng; Shi Zhao; Maggie H Wang; Zuyao Yang

This study has limitations. First, the cases were retrieved from publicly available reports, and many cases were excluded because there were no details available for estimating the parameters. Thus, the representativeness of cases could be a concern. A comparison of the age and sex of included cases with those of 72314 cases in China showed that they are generally similar. 29 Previous studies suggested that publicly reported cases may overrepresent the severe ones. However, based on 329 cases (28.48%) with relevant information available, non-severe cases appeared to account for a higher proportion in the present study than in the previous one on 72314 cases in China. The second limitation of this study is that the upper limit of latent period was based on only 11 pairs of infector-infectee. Larger studies are needed to obtain a more robust estimate. The third limitation is that by using the upper limit of latent period instead of the real latent period in formula (2), in our case, could lead to a slightly smaller value of R0.