Internal travel and risk of dengue transmission in Colombia/Desplazamientos internos y riesgo de transmisión del dengue en Colombia

Human behavior plays a key role in the dynamics of dengue transmission. However, research on the relationship between human movement and dengue transmission within endemic countries is limited. From January 2008 to December 2011, the authors of this study conducted a retrospective analysis of imported dengue infections in Bogota, Colombia. Bogota is a vector-transmission-free city that is also the capital district and most populated municipality in Colombia. The study revealed that 1) Bogota inhabitants acquired dengue infection in diverse localities throughout the country but the largest proportion of cases (35.6%) were contracted at popular tourist destinations in dengue-endemic areas near Bogota (< 200-km radius from city limits), and 2) the number of imported dengue cases increased after major holidays, a transmission pattern not seen in dengue-endemic areas, where disease incidence correlates with rainy periods. It is therefore recommended that physicians consider the effect of travel when diagnosing their patients' illnesses, especially outside dengue-endemic areas where diagnosis of the disease can be challenging due to its nonspecific symptoms. The study also showed that analysis of dengue cases imported to regions free of vector transmission can generate an evidence-based model for characterizing the impact of human movement on the spread of diseases like dengue in countries where they are endemic. Key words Dengue; travel; endemic diseases; Colombia. El comportamiento humano es un factor clave en la dinamica de transmision del dengue. Sin embargo, la investigacion sobre la relacion entre los desplazamientos de personas y la transmision del dengue en los paises con endemicidad es escasa. Los autores realizaron un analisis retrospectivo de las infecciones por dengue importadas a Bogota, Colombia, de enero del 2008 a diciembre del 2011. Bogota es una ciudad libre de transmision por vectores que ademas es la capital y tambien el municipio mas poblado de Colombia. El estudio revelo que: 1) los habitantes de Bogota contraian la infeccion por dengue en diferentes localidades del pais, pero la mayor proporcion de casos (35,6%) se habia registrado en destinos turisticos populares de zonas endemicas cercanas a Bogota (en un radio de < 200 km respecto de los limites de la ciudad), y 2) el numero de casos importados de dengue aumentaba despues de los feriados mas importantes, un patron de transmision que no se observaba en las zonas endemicas, en las que la