Environmental and socioeconomic determinants of leptospirosis incidence in Colombia.

Human leptospirosis is an infection that most often affects tropical countries. Since 2007, Colombia requires the notification of disease cases, enabling the observation of an increase in cases in recent years. The objectives of this article were to analyze environmental and socioeconomic variables and to evaluate their relationship with human leptospirosis cases. This is an ecological study on human leptospirosis cases aggregated by municipality and reported between 2007 and 2016. Spatial aggregation assessment was made using the Getis-Ord Gi method, and negative binomial regression was used to evaluate the relationship between environmental and socioeconomic variables with human leptospirosis. During the study period, 9,928 cases of human leptospirosis were reported, and 58.9% of municipalities reported at least one case. Four hotspots of human leptospirosis, including 18 municipalities, were identified. The results of the negative binomial model confirmed the importance of the effects of education, poverty and some climatic variables on the decadal incidence rate of human leptospirosis. Our results confirm the importance of socioeconomic determinants such as social marginality associated with violence and education, as well as ecological variables such as rainfall, height above sea level and forest coverage on the incidence rate of human leptospirosis at municipal scale.

Environmental and socioeconomic determinants of leptospirosis incidence in Colombia / Determinantes ambientales y socioeconómicos asociados con incidentes en casos de leptospirosis en Colombia / Determinantes ambientais e socioeconômicos associados a casos incidentes de leptospirose na Colômbia

Human leptospirosis is an infection that most often affects tropical countries. Since 2007, Colombia requires the notification of disease cases, enabling the observation of an increase in cases in recent years. The objectives of this article were to analyze environmental and socioeconomic variables and to evaluate their relationship with human leptospirosis cases. This is an ecological study on human leptospirosis cases aggregated by municipality and reported between 2007 and 2016. Spatial aggregation assessment was made using the Getis-Ord Gi method, and negative binomial regression was used to evaluate the relationship between environmental and socioeconomic variables with human leptospirosis. During the study period, 9,928 cases of human leptospirosis were reported, and 58.9% of municipalities reported at least one case. Four hotspots of human leptospirosis, including 18 municipalities, were identified. The results of the negative binomial model confirmed the importance of the effects of education, poverty and some climatic variables on the decadal incidence rate of human leptospirosis. Our results confirm the importance of socioeconomic determinants such as social marginality associated with violence and education, as well as ecological variables such as rainfall, height above sea level and forest coverage on the incidence rate of human leptospirosis at municipal scale.

La leptospirosis humana es una infección que afecta a la mayoría de países tropicales. Desde 2007, la notificación de esta enfermedad es obligatoria en Colombia, reflejando un aumento de casos observado durante los últimos años. Los objetivos fueron analizar las variables ambientales y socioeconómicas y evaluar su relación con los casos de leptospirosis. Se llevó a cabo un estudio ecológico de casos de leptospirosis humana agregados por municipio, registrados entre 2007 y 2016. La evaluación de la agregación espacial fue desarrollada mediante el Getis-Ord Gi method, y se implementó una regresión negativa binomial para evaluar la relación entre las variables ambientales y socioeconómicas con la leptospirosis humana. Durante el periodo de estudio, se registraron 9.928 casos de leptospirosis humana, y un 58,9% de los municipios informaron de al menos un caso de leptospirosis. Se identificaron cuatro epicentros de leptospirosis humana, incluyendo 18 municipios. Los resultados del modelo binomial negativo confirmaron la importancia de los efectos de la educación, pobreza y algunas variables climáticas en la tasa de incidencia de leptospirosis humana por decenios. Nuestros resultados confirmaron la importancia de determinantes socioeconómicos tales como: marginalidad social, asociada con la violencia y educación, así como variables ecológicas como: precipitaciones, altura sobre el nivel del mar y superficie forestal en la tasa de incidencia de la leptospirosis humana dentro una escala municipal.

A leptospirose humana é uma infecção que majoritariamente afeta países tropicais. Desde 2007, a notificação da doença é compulsória na Colômbia, o que levou a um aumento do número de casos nos últimos anos. Os objetivos foram analisar variáveis ambientais e socioeconômicas e avaliar sua relação com casos de leptospirose humana. Foi feito um estudo ecológico de casos de leptospirose humana notificados entre 2007 e 2016 agregados por município. Uma análise de agregação espacial foi desenvolvida por meio do método Getis-Ord Gi e regressão binomial negativa foi implementada para avaliar a relação entre variáveis ambientais e socioeconômicas e leptospirose humana. Durante o período do estudo, 9.928 casos de leptospirose humana foram notificados e 58,9% de municípios notificaram ao menos um caso de leptospirose. Quatro hotspots incluindo 18 municípios foram identificados. Os resultados do modelo binomial negativo confirmaram a importância dos efeitos de educação, pobreza e algumas variáveis climáticas na taxa de incidência decenal de leptospirose humana. Nossos resultados confirmam a importância de determinantes socioeconômicos tais como marginalidade social associada a violência e educação, bem como as variáveis ecológicas, tais como precipitação, altitude acima do nível do mar e cobertura florestal sobre a incidência de leptospirose humana no nível municipal.

Environmental and socio-economic determinants associated with the occurrence of cutaneous leishmaniasis in the northeast of Colombia.

Background: Cutaneous leishmaniasis (CL) is a vector-borne disease that is widely distributed in most tropical regions. Colombia has experienced an important increase in its incidence during the last decade. There are CL transmission foci in the Colombian departments of Santander and Norte de Santander. Objectives: To identify environmental and socio-economic variables associated with CL incidence in the municipalities of the northeast of Colombia between 2007 and 2016. Methods: This was an ecological study of CL cases aggregated by municipality. The cases reported during the study period were analyzed with a negative binomial regression to obtain the adjusted incident rate ratio for environmental and socio-economic variables. Findings: During the study period, 10 924 cases of CL were reported, and 110 (86.6%) municipalities reported at least one CL case. The coverages of forest (aIRR 1.05, 95% CI 1.03-1.07), heterogeneous agricultural zones (aIRR 1.04, 95% CI 1.02-1.06) and permanent crops (aIRR 1.07, 95% CI 1.02-1.12) were associated with a higher incidence of CL. Conversely, urban functionality (aIRR 0.95, 95% CI 0.92-0.96), minimal-altitude above sea level (aIRR 0.84, 95% CI 0.79-0.90) and shrub coverage (aIRR 0.98, 95% CI 0.95-1.0) were negatively associated with the incidence of CL in the municipality. Main conclusions: Our results confirm the importance of environmental determinants, such as height above sea level, and coverage of forest, permanent crops and heterogeneous agricultural zones, for the occurrence of CL; these findings also suggest the importance of shrub coverage. Furthermore, urban functionality was a socio-economic determinant independently associated with CL incidence.