Climatic, socioeconomic, and migratory factors on the epidemiological dynamics of cutaneous leishmaniasis in Colombia, 2007–2021

The World Health Organization considers cutaneous leishmaniasis (CL) to be one of the most important neglected tropical diseases (NTDs). The application of geostatistical models, in conjunction with sociodemographic and environmental factors, enables the understanding of disease epidemiology and facilitates the implementation of targeted measures and effective case management. This research aimed to evaluate the association between climatic, sociodemographic, and socioeconomic factors with the monthly CL incidence rate at the municipality level in Colombia from 2007 to 2021. An ecological study was conducted, including laboratory-confirmed notifications of CL reported in municipalities located below 1,700 meters above sea level through the National Public Health Surveillance System. Climate data were sourced from NASA, and sociodemographic and socioeconomic variables were obtained from the National Planning Department. Hierarchical spatio-temporal regression models within a Bayesian framework were used to analyze the monthly CL. A total of 121,828 cases of CL were analyzed, with an annual median of 7,605 cases. Standardized incidence rates (SIR) ranged from 0 to 16,072 per 100,000 population (median: 105.7; IQR: 46.7-419). Eight of the 11 studied factors were associated with the monthly cases of CL: rainfall, urban dimension, and Venezuelan migration were associated with a decrease in CL cases, while qualitative housing deficit, internal migration, the multidimensional poverty index, the index of unmet basic needs, and forest coverage were associated with an increase in CL cases. CL incidence in Colombia fluctuated during the study period, with high spatial heterogeneity linked to climatic, sociodemographic. and socioeconomic factors. These findings highlight the necessity for customized territorial approaches to the prevention and control of CL, emphasizing the importance of considering municipal characteristics and aligning strategies with the Colombian Strategic Plan for CL.Author summary: Cutaneous leishmaniasis (CL) remains one of the most important tropical diseases worldwide, according to the World Health Organization. By using mathematical models, researchers can better understand how this disease behaves and identify the most effective ways to control it. Our study looked at over 120,000 CL cases reported across Colombia between 2007 and 2021, examining how factors like weather patterns, poverty levels, migration, and environmental conditions influenced the disease’s spread. The data were collected from NASA and Colombian government sources, and showed that most cases occurred in young adult men. Out of the 11 factors we studied, 8 were associated with the frequency of CL cases. Interestingly, we found that heavy rainfall, urban environments, and immigration from Venezuela were associated with fewer CL cases. On the other hand, poverty, internal migration within Colombia, and forested areas were associated with more cases. These results tell us that prevention efforts need to be adapted to each region’s specific conditions, taking into account local environmental and social factors that affect the disease’s spread.