Differences between the socioeconomic strata. Credit: The American Journal of Tropical Medicine and Hygiene (2025). DOI: 10.4269/ajtmh.24-0665

A new study led by researchers from the University of Eastern Finland and a team of international collaborators shows that dengue outbreaks in Medellín, Colombia, are strongly linked to patterns of urban development and socioeconomic status. The findings highlight the potential of leveraging land-use planning and targeted public health strategies to more effectively control dengue in hyperendemic areas.

By analyzing more than 40, 000 georeferenced dengue cases recorded between 2010 and 2020, the researchers found that just 26% of the city's neighborhoods accounted for 50% of all infections. These "hotspot" areas were predominantly located in low- and middle-income communities with built-up land cover. In contrast, neighborhoods with higher socioeconomic status and more green space experienced far fewer outbreaks. The research is published in The American Journal of Tropical Medicine and Hygiene.

"What's striking is that many of these hotspots are not isolated incidents. Some neighborhoods were affected year after year—up to seven years in some cases, " says Doctoral Researcher Juliana Pérez-Pérez, the study's lead author, from the University of Eastern Finland.

Using spatial statistics across 249 barrios in Medellín, the research team identified both single-year and recurrent hotspots. These patterns varied depending on whether the year was classified as epidemic, non-epidemic or severe epidemic, but certain areas consistently appeared as high-risk zones.

Traditional dengue control programs tend to apply the same measures across entire cities, but the findings suggest a more strategic approach is needed. By combining epidemiological surveillance with insights from land use and urban planning, public health interventions can be more targeted and effective.

"Dengue is often seen as a challenge for the Global South, but the conditions that favor its spread—urbanization, social inequality and warming climate—are now increasingly present elsewhere too, " Pérez-Pérez adds.

"This study shows that the spatial and social dynamics of dengue are not random. Recognizing how land use and socioeconomic status shape disease risk can help us not only target local responses in places like Medellín, but also prepare other regions, including parts of Europe, for what may soon become a growing public health challenge."

The study emphasizes the importance of integrating disciplines, such as public health, ecology, urban geography and spatial analysis, to better understand and respond to the spread of mosquito-borne diseases in urban environments.

More information: Juliana Pérez-Pérez et al, Effect of Socioeconomic Strata and Land Cover on Dengue Hotspots in Medellin, Colombia, The American Journal of Tropical Medicine and Hygiene (2025). DOI: 10.4269/ajtmh.24-0665  Journal information: American Journal of Tropical Medicine and Hygiene