Uttar Tolarbagh Model—an Investigation of a COVID-19 Case Led to the First Localized Community Approach for Containment of COVID-19 in Dhaka City, Bangladesh, March–May 2020

Abstract

On 23 Mar 2020, Uttar Tolarbagh, a two-square-kilometer walled-in area in Dhaka, was locked down to contain a COVID-19 outbreak. We evaluated whether localized restrictions on entry and exit points could prevent the spread of COVID-19. We traced contacts and conducted active surveillance from 20 Mar to 10 Apr 2020. Contacts were those within one meter of a confirmed COVID-19 case for ≥15 minutes between two days before and 14 days after the onset of symptoms. We collected swabs from all persons with respiratory symptoms. The positivity rate was calculated by dividing the number of positive samples by the total number of samples tested. The Uttar Tolarbagh House, Flat Owners’ Association and the religious teacher of Masjidul Ahsan, the only mosque in Uttar Tolarbagh, discouraged local gatherings and ensured social distancing during mosque prayers. We identified 400 contacts; 156 were symptomatic and 16 tested positive, of whom eight were hospitalized and two died. SARS-CoV-2 PCR positivity rates among symptomatic contacts were 40% (2/5) before containment, 10% (15/152) during containment, and 0% (0/33) after containment. The last case’s disease onset date was 5 April, and Uttar Tolarbagh remained COVID-19 free until 12 May 2020. Social distancing was observed by the field investigation team on the roads and within the mosque during the lockdown. Our findings suggest that the neighborhood lockdown, isolation of cases, quarantine and contact tracing, evacuation of COVID-19 patients, and community engagement helped to contain COVID-19 transmission in a densely populated area of Dhaka City.