[Epidemiological investigation of a family clustering of COVID-19]

Objective: To investigate the epidemiological characteristics of a family clustering of COVID-19. Methods: Field epidemiological survey was conducted. Results: Case 1 of the long-term residents from Hubei province was the source of infection of this family clustering. There were 6 cases (from case 2 to case 7) infected in the whole incubation period. The incubation period was more than 14 days for 3 of the second-generation cases. Routes of transmission included respiratory droplets (from case 1 transmitted to case 6, from case 1 to her family members) and close contact (from case 1 to other cases in her family). All the age groups were generally susceptible, while elderly were easier to progress to critically ill. Besides respiratory symptoms, there were also gastrointestinal symptoms, of which diarrhea was the most common one. Conclusions: Family clustering had been an important part for COVID-19 cases.