SARS-CoV-2 Surveillance in Migrant Workers during the first wave outbreak of COVID-19 in Brunei Darussalam

Migrant workers are at a high risk of exposure to COVID-19 due to their work and residential status. Surveillance for SARS-COV-2 in this group is important for early detection of infection and breaking the chain of disease transmission in the workplace and community. This report describes an enhanced active surveillance strategy for COVID-19 in migrant workers of Brunei Darussalam during the first wave of the outbreak in 2020.

Active and phased surveillance of migrant workers for SARS-CoV-2 was conducted by the Ministry of Health on a total of 9443 workers, in 2020. Surveillance was carried out using a nasopharyngeal swab test for SARS-CoV-2 reverse transcription-polymerase chain reaction (RT PCR) in phases I and II, whilst a rapid antigen test was used in phase III.

Phase I included 7073 workers from 714 workplaces; phase II covered 860 workers from 190 workplaces; and phase III covered 1510 workers. Three positive cases were detected during phase I of the surveillance. No migrant worker was tested positive for SARS-CoV-2 during the second and third phases of surveillance.

The number of positive cases detected was small; however, this strategy actively searched for the presence of SARS-CoV-2 among the migrant worker population in the country, and further confirmed the absence of any hidden local transmission of cases in this population.