Global health. The current scenario and future perspectives

146 transmitted infections (STIs). The main objective of second-generation surveillance is to monitor the epidemic and high-risk behavior trends to provide vital information for designing prevention programs and evaluating their impact. In general, second-generation HIV/STI surveillance is based on biological surveillance (sentinel serological surveillance of vulnerable populations, routine testing of blood donors, etc.), behavioral surveillance (repeated cross-sectional studies of the general population and specific subgroups) and other sources of information (HIV/AIDS case surveillance, death registries, etc.). Different authors have discussed the future and challenges of public health surveillance. The main issues include improving surveillance towards a more comprehensive system for collecting data on risk factors, intervention and prevention strategies and exploring new solutions that involve investigating the interactions between biological, social, psychological and environmental factors. Other areas of focus include developing large-scale data collection systems based on the population and in support of universal and active surveillance, as well as multiple methodologies and systematic processes for selecting indicators. Additionally, linking the surveillance system with an efficient data-analysis system that can generate early warning signals for health trends and risk factors is important. Providing direct and effective mechanisms for supplying information in the public health decision-making process, developing better ways to disseminate information including risk communication and achieving health for all regardless of age, race or socioeconomic level, including the opportunity to contribute to the decision- making process, are also key goals (Choi, 1998, 2012; Choi & Pak, 2001; Hall et al., n. d.). Conventional public health surveillance mainly relies on the reporting of disease cases through the healthcare systems of countries, allowing for the generation of statistics and a rapid response to events and health emergencies. However, it does not delve into the multiple determinants of disease, nor does it allow for the characterization or in-depth analysis of relevant aspects of health in vulnerable populations. Active surveillance, especially in bio-behavioral studies on HIV/STIs, could be considered an exception. Therefore, to expand the scope of current surveillance, there has been a discussion in recent years about the need for another approach - a broad approach that involves community members in identifying and reporting health events that occur in their areas. (Guerra et al., 2019). Community-based surveillance (CBS) is an active participatory process aimed at detecting, reporting, responding to and monitoring health events in the community. Despite being an innovative strategy developed formally no more than 20 years ago, literature shows that CBS also presents a series of limitations and challenges, mainly related to its application in