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

We conducted a retrospective study of the epidemiological and clinical characteristics of COVID-19 cases in Shenzhen from Jan 1 to Feb 28, 2020. COVID-19 case was defined in accordance with the WHO interim guidelines and the National Guidelines in Diagnosis and Treatment Scheme for COVID-19 (Sixth edition) (8, 9) . Sputum, blood, broncho-alveolar lavage fluid, nasopharyngeal swab, or oropharyngeal swab were collected from each patient and tested using real-time polymerase chain reaction (RT-PCR) for SARS-CoV-2. A cycle threshold value less than 37 was defined as PCR test positive. Virus detection was first done by hospitals or districted centers for disease control and prevention (CDC), and positive results were further confirmed by Guangdong Provincial CDC (before Jan 30, 2020) or Shenzhen CDC (after Jan 30, 2020). For each confirmed case, detailed epidemiological investigations were conducted by local epidemiologists and public health workers. All confirmed cases were immediately reported to the National Infectious Disease Information System for COVID-19, which was amended as a Class B notifiable infectious disease on Jan 20, 2020.