Investigation on a family cluster of COVID-19 in Ningbo / 预防医学

ABSTRACT

Objective@#To report an investigation of a family cluster of coronavirus disease 2019 ( COVID-19 ) in Ningbo, so as to provide reference for the prevention and control measures.@*Methods@#According to the COVID-19 Prevention and Control Program ( fourth version ) , an epidemiological investigation was conducted to collect the demographic information, clinical features and exposure history, to find the close contacts, and to figure out the source and route of infection. @*Results@#Twelve confirmed cases and one asymptomatic case were reported. The attack rate was 16.05%. Among them, five were males and eight were females; the age ranged from 11 to 85 years old, with a median of 39 years old; most had mild symptoms. The incubation period was 2-13 days, with a median of 6.5 days. The first case ( Case 1 ) developed the symptoms on January 22, and had close contact with Zhang, an asymptomatic case, on January 20. Zhang was related to a cluster in the Buddhist assembly on January 19. Case 1, who caused the spread of the epidemic among family members, participated in several family visits and dinners from January 22 to 27 with other 24 families, resulting in six secondary cases and six third-generation cases. There were 54 close contacts except the family members, no infection was found. @*Conclusion@#This family cluster may result from the close contact with an asymptomatic case, and then spread within families through having dinners and living together.