What is EcSS2.0?

Towards the end of 2021, the pandemic of COVID-19 had caused over 300 million infections globally, while its spread had engendered multiple epidemic waves in Hong Kong. In order to systematically assess the population risk of SARS-CoV-2 and other respiratory pathogens in Hong Kong, EcSS2.0 as an online community-based surveillance platform was officially launched in 2022.

Throughout the study period, participants from random households are invited to answer a monthly web-based survey on their exposure to SARS-CoV-2 and activity pattern in different settings during the past 1 month. Following data analysis, the findings could help keep track of the exposure risk of SARS-CoV-2 in different settings and time periods in Hong Kong. The study of population activity pattern in the community could also facilitate the identification of high-risk settings prone to the occurrence of respiratory outbreaks.

Community-based surveillance has played an increasingly important role in public health systems worldwide. At the same time, surveillance platforms resembling EcSS2.0 have been in operation in more cities and countries to serve a variety of purposes, ranging from early detection of infectious disease outbreaks to long-term monitoring of public health threats. An application was noted during the Ebola epidemic in West Africa in 2014, when community members were invited to help identify and report events suggestive of Ebola transmission. The collective efforts from society had greatly contributed to the successful control of outbreaks. Through EcSS2.0, it is hoped that this study could help strengthen the knowledgebase of SARS-CoV-2 epidemiology in the community, and through participation, contribute to the development of effective anti-epidemic strategy.