Testing strategies to contain COVID-19 in migrant worker dormitories

Abstract

Introduction COVID-19 transmission within overcrowded migrant worker dormitories is an ongoing global issue. Many countries have implemented extensive control measures to prevent the entire migrant worker population from becoming infected. Here, we explore case count outcomes when utilising lockdown and testing under different testing measures and transmissibility settings. Methods We built a mathematical model which estimates transmission across 10 different blocks with 1000 individuals per block under different parameter combinations and testing conditions over the period of 1 month. We vary parameters including differences in block connectivity, underlying recovered proportion at the time of intervention, case importation rates and testing protocols using either PCR or rapid antigen testing. Results We estimate that in a relatively transmissible environment, fortnightly PCR testing at a relatively low initial recovered proportion at 40%, low connectivity where 10% of contacts occurred outside of the infected individuals’ block and high importation rate of per day, results in an average of 39 (95%Interval: 9–121) new COVID-19 cases after one month of observation. Similar results were observed for weekly rapid antigen testing at 33 (9–95) cases. Interpretation Our findings support the need for either fortnightly PCR testing or weekly rapid antigen testing in high population density environments such as migrant worker dormitories. Repeated mass testing is highly effective, preventing localized site outbreaks and reducing the need for site wide lockdowns or other extensive social distancing measures within and outside of dormitories. Funding This research is supported by DEMOS funding from Saw Swee Hock School of Public Health, National University of Singapore, the COVID-19 grant under Singapore's National Medical Research Council Centre Grant Programme – the Singapore Population Health Improvement Centre (NMRC/CG/C026/2017_NUHS) and COVID-19 Research Fund (COVID19RF-004).

Optimization of Screening Strategies for COVID-19: Scoping Review

“…Subsequently, 476 abstracts were reviewed, and 95 publications received a full-text review. Finally, 62 publications were included in the synthesis (the data-charting form is available in Multimedia Appendix 2 [ 20 - 46 ]).…”

“…Baker et al [ 45 ] found that if the number of screening tests per day was slightly higher than the daily testing capacity, it would not cause a burden on testing, but more cases could be found and transmission could be reduced more effectively. Koo et al [ 46 ] assessed the impact of biweekly PCR tests or weekly RATs on the number of new infections and infectivity in areas with a high population density (such as workers’ dormitories) and found that biweekly PCR testing (39 new cases per month) was as effective as weekly RATs (33 new cases per month) and could prevent local outbreaks.…”

“…Self-detection is often an alternative when professional testing capabilities are insufficient, and self-detection and laboratory testing complement each other. A few studies have compared laboratory tests with self-tests or combined antigen tests with PCR tests [ 35 , 38 , 39 , 42 , 46 , 86 ]. Yu et al [ 82 ] found that the PCR pooled test tended to be more cost-effective at low prevalence because it allows more people to be tested with existing equipment and quarantines more patients with presymptomatic and asymptomatic infections to prevent future infections.…”