Epidemiological characteristics of 2019 novel coronavirus family clustering in Zhejiang Province

Objective: Family clusters of Novel coronavirus pneumonia in Zhejiang province were analyzed to provide epidemiological basis for disease control. Methods: The data of family clusters occurred from January 20 to February 10 in Zhejiang Province were collected. Descriptive analysis was used to analyze the clinical symptoms and the serial interval between the subsequent cases and the index cases. Chi-square test was used to analyze the age distribution, gender distribution and the relationship between the subsequent cases and the index cases. Results: 391 cases including 148 family index cases, 189 subsequent cases and 54 asymptomatic infected cases. The clinical symptoms between family index cases and subsequent cases are similar, fever is the most common symptoms in the two groups 114 (77.03%) and 92 (48.68%) respectively, the cases with diarrhea symptoms accounted for the least proportion, which were 7 (4.73%) and 5 (2.65%). The serial interval between the family index cases and the subsequent cases [M (P(25), P(75))] was 3.00 (1.00, 6.00) days. Family secondary attack rate for subsequent cases and asymptomatic infected cases are 31.61% and 43.20% respectively, the family secondary attack rate of the spouses of the family index cases is 63.87%, and are higher than that of their children (30.53%), parents (28.37%) and other family members (20.93%), the difference was statistically significant. Conclusion: 2019 novel coronavirus has shorter serial interval and higher family secondary attack rate, the secondary attack rate of spouses is higher than other family members.