Event-based surveillance in middle- and low-income countries: An evidence map.

Event-based surveillance is an important strategy for the early detection of outbreaks of all types of diseases, especially in low- and middle-income countries. This research focuses on an evidence map, which systematizes and graphically represents the information gathered on the effectiveness of various interventions in these contexts. Key interventions include data quality, training, communication, multisectoral collaboration, timeliness, mortality and morbidity reduction, cost-effectiveness, early response to events, sensitivity, signals, and usefulness for real events. In this study, a review and evaluation of the literature was conducted on a total of 22 systematic reviews; 15 met the inclusion criteria, containing a total of 82 open-access primary articles. The quality of the evidence was assessed using the AMSTAR tool, identifying reviews with high, medium, and low reliability. The results show that event-based surveillance has been successfully implemented in countries such as the United States, Brazil, China, Australia, Canada, India, Japan, New Zealand, Taiwan, the Netherlands, the United Arab Emirates, and others. From the evidence gathered in these countries, it is clear that event-based surveillance improves early outbreak detection, alert response, and minimizes the spread of diseases. Further research and improvement of these strategies are needed for effective early detection and response to public health events.