Epidemiological Investigation of the First 135 COVID-19 Cases in Brunei: Implications for Surveillance, Control, and Travel Restrictions

Abstract

Studies on the early introduction of SARS-CoV-2 in a naive population have important epidemic control implications. We report findings from the epidemiological investigation of the initial 135 COVID-19 cases in Brunei and describe the impact of control measures and travel restrictions. Epidemiological and clinical information was obtained for all confirmed COVID-19 cases, whose symptom onset was from March 9 to April 5, 2020. The basic reproduction number (R0), incubation period, and serial interval (SI) were calculated. Time-varying R was estimated to assess the effectiveness of control measures. Of the 135 cases detected, 53 (39.3%) were imported. The median age was 36 (range = 0.5-72) years. Forty-one (30.4%) and 13 (9.6%) were presymptomatic and asymptomatic cases, respectively. The median incubation period was 5 days (interquartile range [IQR] = 5, range = 1-11), and the mean SI was 5.4 days (SD = 4.5; 95% CI: 4.3, 6.5). The reproduction number was between 3.9 and 6.0, and the doubling time was 1.3 days. The time-varying reproduction number (Rt) was below one (Rt = 0.91; 95% credible interval: 0.62, 1.32) by the 13th day of the epidemic. Epidemic control was achieved through a combination of public health measures, with emphasis on a test-isolate-trace approach supplemented by travel restrictions and moderate physical distancing measures but no actual lockdown. Regular and ongoing testing of high-risk groups to supplement the existing surveillance program and a phased easing of physical distancing measures has helped maintain suppression of the COVID-19 outbreak in Brunei, as evidenced by the identification of only six additional cases from April 5 to August 5, 2020.

The incubation period during the pandemic of COVID-19: a systematic review and meta-analysis

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New norms and opportunities from the COVID-19 pandemic crisis in a higher education setting: perspectives from Universiti Brunei Darussalam

“…Meanwhile, higher education institutions mostly remained open and essential daily operations continued. However, in minimising the risk of any transmission possibilities on the campus grounds, precautionary measures based on the guidelines provided by the Ministry of Health were imposed (Wong et al, 2020a). The necessary precautions included temperature checkpoints at strategic locations with access limited to a single entry and exit point in all campus buildings, mandatory practices of social and physical distancing and the scheduled "Work from Home" arrangements for all staff, as stipulated by the Prime Minister's Office (2020).…”

Presymptomatic transmission of SARS-CoV-2 infection: a secondary analysis using published data

“…These findings are supported by quantitative studies based on contact tracing, with reports of serial intervals or generation times similar in duration or shorter than incubation periods in some situations, 27–32 and even cases of symptoms manifesting in the infectee prior to the infector. 24 30 33–37 …”