Analysis of SARS-CoV-2 transmission in different settings, among cases and close contacts from the Tablighi cluster in Brunei Darussalam

Abstract

AbstractWe report the transmission dynamics of SARS-CoV-2 across different settings from the initial COVID-19 cluster in Brunei, arisen from 19 attendees at the Malaysian Tablighi Jama’at gathering and resulted in 52 locally transmitted cases. Highest non-primary attack rates(ARs) were observed at a subsequent local religious gathering (14.8% [95%CI: 7.1,27.7]) and in the household (10.6% [95%CI: 7.3,15.1]. Household ARs of symptomatic cases were higher (14.4% [95%CI: 8.8,19.9]) than asymptomatic (4.4% [95%CI: 0.0,10.5]) or presymptomatic cases (6.1% [95%CI: 0.3,11.8]). Low ARs (<1%) were observed for workplace and social settings. Our analysis highlights that SARS-CoV-2 transmission varies depending on environmental, behavioural and host factors. We identify ‘red flags’ of potential super-spreading events, namely densely populated gatherings for prolonged periods in enclosed settings, presence of individuals with recent travel history, and group behaviours such as communal eating, sleeping and sharing of personal hygiene facilities. We propose differentiated testing strategies that account for transmission risk.Article summary lineWe highlight the variability of SARS-CoV-2 transmission across different settings, identify settings at highest risk, and characterize the role of environmental, behavioural, and host factors in driving SARS-CoV-2 transmission.