Risk factors of COVID-19 transmission among workers at a large - scale factory in Vietnam, 2021

Tóm tắt

On 27th January 2021, an outbreak of COVID-19 occurred at a large-scale factory (Factory P) in Cong Hoa industrial zone, Chi Linh district, Hai Duong province, Vietnam. We conducted a retrospective observational study of the epidemiological profile of 1,180 workers of Factory P between 27 January and 30 March 2021, to describe the epidemiological features and risk factors of disease transmission. Data of confirmed cases were extracted from National Notifiable Infectious Disease Information System. A self - administered questionnaire was used to obtain information on transmission risk within and outside the workplace from all participants. Multivariate logistic regression models were used to explore the risk factors associated with COVID-19 infection. A total of 182 COVID-19 confirmed cases were identified (mean age [SD] = 30.4 [6.5], 73.9% female). The attack rate of the outbreak was 15.4% (95%CI: 13.4 - 17.5%). Factors that increased the risk for COVID-19 transmission included having work -shifts over 12 hours (OR 64.1; 95%CI: 8.1 - 509.9), working in a confined workspace (OR 1.6; 95%CI: 1.1 - 2.4), frequent communication with peers (OR 1.8; 95%CI: 1.2 - 2.6), caring for sick people (OR 1.9; 95%CI: 1.2 - 3.0), and close contact with a suspected COVID-19 case (OR 1.8; 95%CI: 1.2 - 2.7). In addition, being male, having an underlying condition, using the shuttle bus for travel to and from work, and joining mass gathering events increased the likelihood of infection but ORs were non-significant (p > 0.05). A high attack rate of the COVID-19 outbreak was identified at Factory P. Shorter working shift, open workspace and reduced peer-to-peer contact could facilitate the outbreak control measures.