Contact tracing in epidemiology: Lessons learnt from COVID-19

Contact tracing is a powerful public health tool used in identifying people that might have been in contact with an infected person to assess the potential of being infected and transmitting the diseases. This review explores the history, implementation, and effects of contact tracing, as a significant public health strategy during the COVID-19 pandemic. The review started by giving a historical summary of contact tracing, then links it to early efforts at disease control for diseases such smallpox and TB. We further examine pre-COVID-19 contact tracing approaches, such as manual and early digital tools employed during past epidemics like Ebola and Zika. While investigating the development of digital innovations—such as Bluetooth-based applications and location data tracking—that were used to improve tracing efforts—the review emphasises the efficacy and problems of conventional manual contact tracing during COVID-19. Notably, we examine the hybrid models that combine manual and digital approaches, proving higher compliance and efficiency. Along with the difficulties countries with less efficient tracing systems—such as the United States and India—the review also includes worldwide case studies showing successful implementations in countries such Taiwan, South Korea, and New Zealand. Emphasising the need of public trust and the effect of the digital divide, it also covers public compliance and social elements affecting involvement in contact tracing programs. In order to strengthen public health preparedness for next pandemics, we offer potential options for contact tracing resilience, arguing for contact systems backed by technological developments and ethical protections. Informing best practices for next epidemiological tactics, this thorough analysis uncovers important insights and lessons learnt from the COVID-19 pandemic.