ABSTRACT
Objective: To investigate and analyze the epidemiological characteristics of a cluster of coronavirus disease 2019 (COVID-19) spread by a super spreader in Taizhou, Zhejiang Province, and provide reference for prevention and control of COVID-19. Methods: The field epidemiological investigation was conducted to investigate the confirmed cases and close contacts;the data were analyzed with descriptive method. Chi-squared test was used to compare the differences of attack rates among close contacts. Results: A total of 23 epidemiological related cases were identified, including 20 confirmed cases and 3 asymptomatic infection cases. Thirteen (56.52%) were males, ten (43.48%) were females, and the median age was 51 years old with the range of 30 to 70 years old. The second generation case firstly developed symptoms on Jan 19th and was confirmed on Jan 30th, 2020.The first generation cases were from Wuhan and the last case was confirmed on Feb 3rd, 2020.The epidemic spread to the fifth generation with a total attack rate of 6.07% (21/346), among which the third generation case was a super spreader who directly transmitted to 12 subsequent cases with a significantly higher attack rate than other cases (27.27% vs. 2.98%, χ2=39.754, P<0.001). Conclusion: The expansion of the epidemic can be attributed to the lack of timely control of imported personnel from high risk regions, the lacking awareness of novel infectious diseases at the early stage of the epidemic and the appearance of the super spreader. To form a normalized prevention mechanism, it is necessary to improve the alertness of novel infectious diseases among medical staffs and the masses, implement prevention and control strategies in time. © 2021, Editorial Department of Fudan University Journal of Medical Sciences. All right reserved.