The transmission pattern and clinical course of the first 417 patients with COVID-19 infection in Shenzhen, China

OBJECTIVE: To explore the transmission patterns and clinical course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that was first identified in Wuhan, China in December 2019 as clustered and non-clustered cases of coronavirus disease (COVID-19) emerged in Shenzhen, China. METHODS: This retrospective study included the patients that were confirmed by laboratory detection of SARS-CoV-2 in Shenzen between 19 January 2020 and 21 February 2020. Data on the epidemiological and clinical characteristics were analysed. The patients were divided into non-clustered and clustered groups. The time course, intervals between first and second COVID-19 cases and other transmission patterns were compared between the groups. RESULTS: The 417 patients were divided into clustered (n = 235) and non-clustered groups (n = 182). Compared with the non-clustered group, the clustered group had significantly more young (≤20 years) and old (>60 years) patients. The clustered group had significantly more severe cases (nine of 235; 3.83%) compared with the non-clustered group (three of 182; 1.65%). Patients with severe disease spent 4–5 more days of hospitalization than patients with moderate and mild disease. CONCLUSION: This retrospective study analysed the transmission patterns and clinical course of the first wave of COVID-19 infection in Shenzhen, China.