Epidemiological and clinical characteristics of COVID-19 in Shenzhen, the largest migrant city of China

Ying Wen; Lan Wei; Yuan Li; Xiujuan Tang; Shuo Feng; Kathy Leung; Xiaoliang Wu; Xiong-Fei Pan; Cong Chen; Junjie Xia; Xuan Zou; Tiejian Feng; Shujiang Mei

The copyright holder for this preprint . https://doi.org/10.1101/2020.03.22.20035246 doi: medRxiv preprint Shenzhen. The proportion of severe or critical cases in Shenzhen (8.6%) was significantly lower than that reported by Guan et al. in patients across China (15.7%) (15). In our study, older age, breathing problems, and diarrhea were correlated to the clinical severity on admission. Other studies also suggested that these factors were associated with poorer outcomes in patients in Wuhan and elsewhere (5, 15) . Furthermore, the longer time from the first medical visit to hospital admission was associated with higher clinical severity on admission, while surveillance identification was associated with lower clinical severity. Thus the low proportion of severe or critical cases in our study might be explained by the large number of cases identified by surveillance and the short time interval from the first medical visit to hospital admission. Of note, 33 (83.3%) of the severe or critical cases were selfidentified, which might be due to delayed hospital admission. Through active surveillance efforts such as screening of high-risk populations, a large proportion of COVID-19 patients were identified at the early stage of their illness, thus decreasing the possibility of progression to a severe illness. The hospital fatality rate of COVID-19 in Shenzhen (0.7%) was much lower than 14% reported from Wuhan (16), and also lower than 1.4% reported in a countywide study (15). Since data on clinical outcomes were censored in our study, the hospital fatality rate may be underestimated.