1. Quantifying the spatial spread of dengue in a non-endemic Brazilian metropolis via transmission chain reconstruction.
- Author
-
Guzzetta G, Marques-Toledo CA, Rosà R, Teixeira M, and Merler S
- Subjects
- Algorithms, Bayes Theorem, Brazil epidemiology, Cities, Dengue epidemiology, Geography, Humans, Models, Theoretical, Dengue transmission, Dengue virology, Dengue Virus physiology, Spatio-Temporal Analysis
- Abstract
The ongoing geographical expansion of dengue is inducing an epidemiological transition in many previously transmission-free urban areas, which are now prone to annual epidemics. To analyze the spatiotemporal dynamics of dengue in these settings, we reconstruct transmission chains in Porto Alegre, Brazil, by applying a Bayesian inference model to geo-located dengue cases from 2013 to 2016. We found that transmission clusters expand by linearly increasing their diameter with time, at an average rate of about 600 m month
-1 . The majority (70.4%, 95% CI: 58.2-79.8%) of individual transmission events occur within a distance of 500 m. Cluster diameter, duration, and epidemic size are proportionally smaller when control interventions were more timely and intense. The results suggest that a large proportion of cases are transmitted via short-distance human movement (<1 km) and a limited contribution of long distance commuting within the city. These results can assist the design of control policies, including insecticide spraying and strategies for active case finding.- Published
- 2018
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