The PRCS is a prospective, community-based study that aims to explore the epidemiological features of predominant infectious and non-communicable diseases. The baseline investigation spanned from 2009 to 2015, during which participants were recruited if they were permanent residents of the Pearl River Delta Region of China (specifically in Guangzhou, Zhongshan and Shenzhen) and met other inclusion criteria. At baseline, 47% of the participants were men, 98% identified as Han ethnicity, and the median age was 39.63 years, with a slightly higher proportion of individuals over 60 years old and female compared with the general population of Guangdong Province. After the initial survey, a subset of participants (10%) have been followed up every 3-5 years.