Reemergence of arboviruses in the Andean-Amazonian corridor: eco-epidemiological dynamics and surveillance in Colombia, Ecuador, and Venezuela

Abstract

Re-emerging infectious diseases pose a growing threat to global public health, especially in tropical regions where environmental changes, rapid urbanization, declining vaccination coverage, and human mobility facilitate the transmission of various pathogens. Latin America is currently facing an unprecedented epidemiological crisis, with infectious diseases spreading amid conditions of inequality and fragmented health systems. The Andean-Amazonian corridor represents an epidemiological hotspot for various vector-borne diseases. The objective of this article was to analyze the epidemiological trends of re-emerging diseases in these countries from 2023 to 2026, identifying ecological, social, and health factors linked to their re-emergence. The results reveal a sustained increase in arboviruses such as dengue, chikungunya, and yellow fever, as well as the persistence of malaria in Amazonian areas. In Ecuador, 37,840 cases of dengue were reported in 2025, with 65 deaths, while in Colombia, an outbreak of yellow fever was recorded with 132 confirmed human cases from 2024 to 2025. The situation regarding yellow fever in Venezuela during 2025 and 2026 shows signs of reemergence within the regional context of South America, associated primarily with the circulation of the virus in sylvatic cycles and the risk of spread to neighboring areas. The findings indicate that the interaction between climate change, deforestation, migration, and evident weaknesses in epidemiological surveillance, vector control, limited access to health services, infodemic, poor health education, and vaccine hesitancy contribute to the reemergence. In conclusion, it is necessary to implement a One Health approach in Latin America, which is justified not by the number of reported cases, but by the magnitude of what remains undetected and unreported, as well as genomic surveillance to identify variants, trace transmissions, monitor drug resistance, and anticipate outbreaks, thereby transforming our understanding of complex, emerging, and often neglected diseases.