Lessons for future outbreaks from successful contact tracing systems in Asia

Abstract

Countries around the world had utilized contact tracing to support public health responses to curb transmission during the COVID-19 pandemic. In particular, countries in East and Southeast Asia had been effective in their contact tracing responses. To understand their successes, the contact tracing systems of Japan, Thailand, Singapore and Vietnam were comparatively analyzed, including the technical aspects of contact tracing approaches, detection and response structures. Through the comparative analysis, we uncovered the key elements within these successful systems, namely speed, capture and accuracy, designed specific for the countries' settings. For the system to work efficiently, we found that maintaining the balance across speed, capture and accuracy while adapting to the disease epidemiology and environment was essential. Contact tracing will remain a vital strategy to control the next epidemic with a pandemic potential. The lessons learnt could provide guiding principles to help enhance contact tracing systems and prepare for future outbreaks.

Keywords: COVID-19; Contact tracing; Outbreak response; Pandemic preparedness.

Fig. 1

Summary of information sources. Proactive contact tracing, including interviews and epidemiological investigations, was conducted in Japan, Thailand, Singapore and Vietnam and served as the main information source to trace the contacts of confirmed cases. Existing information sources also supplemented contact tracing, such as medical records and digital footprints, which could be assessed through an integrated database platform, reporting channels or direct requests for information. Information captured from mobile technology, including Bluetooth proximity indicators, self-monitoring tools ranging from symptomatic monitoring, health declaration to fit-for-work status and check-in check-out digital mechanisms to monitor point of entry into premises also supported the contact tracing processes.

Fig. 2

Elements of a successful contact tracing system. The common key elements within the contact tracing systems of Japan, Thailand, Singapore and Vietnam were speed, capture and accuracy. Speed was enhanced with efficient teams and established disease surveillance and response structures. Good capture curbed disease transmission through multi-faceted contact tracing, enhanced surveillance, isolation and quarantine. High accuracy was maintained via good communication and empowerment of contact tracers. People, at the center of a successful system, represented the important of engagement and trust with the population. The arrows portrayed the interaction between the elements, and the importance of maintaining resource balance. The success of the system also relied on adaptability of the system to the environment and disease epidemiology.