Mapping Environmental Dimensions of Dengue Fever Transmission Risk in the Aburrá Valley, Colombia

Sair Arboleda,Nicolas Jaramillo-O,A Townsend Peterson

doi:10.3390/ijerph6123040

Abstract

Dengue fever (DF) is endemic in Medellín, the second largest Colombian city, and surrounding municipalities. We used DF case and satellite environmental data to investigate conditions associated with suitable areas for DF occurrence in 2008 in three municipalities (Bello, Medellín and Itagüí). We develop spatially stratified tests of ecological niche models, and found generally good predictive ability, with all model tests yielding results significantly better than random expectations. We concluded that Bello and Medellín present ecological conditions somewhat different from, and more suitable for DF than, those of Itagüí. We suggest that areas predicted by our models as suitable for DF could be considered as at-risk, and could be used to guide campaigns for DF prevention in these municipalities.

Highlights

Dengue fever (DF) is an arboviral disease transmitted to humans by mosquitoes of the genusAedes [1]; its transmission is determined by factors including mosquito density, circulating virus serotypes, and susceptibility of human populations [2]
Given the fact that the home address is not necessarily the infection site, and the occurrence data include certain amounts of error, we considered a base level of omission error that is expected owing to these complications, which has been quantified as parameter E [21]; we selected E = 10 as an appropriate level: that is, we expected occurrence data to include as much as 10% error, given problems with geo-referencing and with identification of true exposure sites
Multiple comparisons conducted in this study showed that coincidence between spatial predictions and independent test points was significantly better than random expectations, suggesting in general that ecological niche modeling (ENM) had predictive power regarding DF case distributions (Table 2)

Summary

Introduction

Aedes [1]; its transmission is determined by factors including mosquito density, circulating virus serotypes, and susceptibility of human populations [2]. Transmission dynamics of vector-borne diseases are inherently spatial processes, so variables linked to vector or case distributions may be a useful basis on which to predict spatial dimensions of transmission in unsampled areas [15]. Occurrence of DF is determined by multiple factors, including environmental dimensions that affect the population biology, development, and behavior of vectors, as well as dimensions that determine the population biology and natural history of the viruses, and even the behavior of humans. Across continental extents and broad areas, environmental factors like humidity, temperature, and rainfall are known determinants of dengue vector development that can limit DF occurrence [16,17,18]. As such, when mosquito occurrence data are not available, DF case data provide a useful basis available for estimating occurrence patterns [19]; Ostfeld et al [15]

Methods

Results

Conclusion