Analysis of epidemiological characteristics of coronavirus 2019 infection and preventive measures in Shenzhen China: a heavy population city

Coronavirus 2019 infection (COVID-19) outbroke in Wuhan, Hubei and spread to all provinces in China and other countries. Shenzhen ranked the top cities outside Wuhan with reported 416 confirmed cases by February 20, 2020. Here, we analyzed the epidemiological characteristics of COVID-19 in Shenzhen and potential link to the preventive strategies for the whole city and inside hospitals. Based on the daily new cases, the epidemic of COVID-19 in Shenzhen can be classified into three phases: the slow increase phase from January 19 to January 28, the rapid increase and plateau phase from January 29 to February 5 and the decline phase since February 6. In the three phases, the number of patients from Hubei decreased, and the number of familial clustering cases increased. The newly diagnosed COVID-19 cases reached its peak around January 31, which was 7 days after the peak date of cases arrival at Shenzhen. A series of early preventive strategies were implemented since January 19, which included detection of body temperature at all entrances of main traffic and buildings, outpatients service specially for patients with fever in all main hospitals in Shenzhen. All the patients with fever were screened with nasal or throat swab PCR detection of coronavirus 2019, Chest CT and blood lymphocyte counting in order to find out early case of COVID-19. Observation wards were established in every main hospital and a designated hospital was responsible for admission and medical care of all confirmed cases. Protection procedure was established for all medical staff involved in the screening and care of suspected and confirmed cases. 14 days isolated observation of all subjects arrived at Shenzhen from Hubei was implemented in February 2. After the implementation of all these strategies and measures, the COVID-19 cases started to decline since February 6. There were almost no community transmission and nosocomial infection occurred in Shenzhen. In conclusion, in situation of major outbreak of respiratory infectious disease, such as COVID-19, in nearby province of Hubei, Shenzhen, a high population density, high proportion of external population and high mobility city, has to face the imported cases and risk of spreading the outbreak into Shenzhen city. The implementation of early preventive strategies and measures in Shenzhen were successful in early identification of COVID-19 cases and prevented major outbreak occurred in Shenzhen. Early identification of imported cases, prevention of family clustering transmission, preventive measures in the public area and very strict infection control procedure in hospital setting are crucial for the successful control of outbreak in Shenzhen.