Risk factors associated with occurrence of COVID-19 among household
persons exposed to patients with confirmed COVID-19 in Qingdao
Municipal, China
Abstract
Tracing and isolation of close contacts is used to control outbreaks of
coronavirus disease 2019 (COVID-19) in China. However, risk factors
associated with occurrence of COVID-19 among close contacts have not
been well described. 106 household contacts were included in this study,
of whom 19 were developed into COVID-19 cases and the secondary attack
rate was 17.9%. Multivariable analysis showed increasing risk of
occurrence of COVID-19 among household contacts associated with female
of index patients (Adjusted Hazard Ratio [aHR] = 5.61, 95%CI =
1.51-20.83), critical disease of index patients ([aHR] = 7.58,
95%CI = 1.66-34.66), effective contact duration with index patients
>2 days ([aHR] = 4.21, 95%CI = 1.29-13.73), and
effective contact duration >11 days ([aHR] = 17.88,
95%CI = 3.26-98.01).The sex and disease severity of index COVID-19
patients, and longer effective contact duration with COVID-19 confirmed
cases could help epidemiologists to identify potential COVID-19 case
among household contacts at an early stage.