Population mobility and dengue fever transmission in a major city in Southeastern Brazil, 2007-2015

Abstract

25Background 26 Around 14% of world dengue virus (DENV) cases occur in the Americas, the majority 27 of them in Brazil. Although socioeconomic, environmental and behavioral correlates 28 of dengue have been analyzed for different contexts, the role played by population 29 mobility on DENV epidemics, especially at the local level, remains scant. This study 30 assesses whether the daily pattern of population mobility is associated with DENV 31 transmission in Campinas, a Brazilian major city with over 1.2 million inhabitants in 32 São Paulo state. 33 Methodology/Principal Findings 34 DENV notifications from 2007 to 2015 were geocoded at street level (n=114,884) and 35 combined with sociodemographic and environmental data from the 2010 Population 36 Census. Population mobility was extracted from the Origin-Destination Survey 37 (ODS), carried out in 2011, and daily precipitation was obtained from satellite 38 imagery. Zero-Inflated Negative Binomial (ZINB) regression models controlled by 39 demographic and environmental factors revealed that high population mobility had a 40 substantial positive effect on higher risk for DENV transmission. High income and 41 residence in apartments were found to be protective against the disease, while 42 unpaved streets, number of strategic points (such as scrapyards and tire repair 43 shops), and precipitation were consistently risk factors for DENV infection.44 Conclusions/Significance 45 The use of fine-scale geographical data can unravel transmission idiosyncrasies not 46 evident from a coarse spatial analysis. Even in a major city like Campinas, the vast 47 majority of population daily mobility occurs at short distances. Based on our results, 48 public policies on DENV transmission control should dedicate special attention to 49 local hubs of population mobility, especially during high transmission weeks and in 50 high dengue incidence areas. 51 52 Author Summary 53 Currently, about half of the world population is at risk of a dengue infection. Numerous 54 studies have addressed the socioeconomic and environmental determinants of the 55 disease. However, little is known about the role played by population mobility on 56 dengue transmission, particularly at the local scale. This study aims at investigating 57 this issue. Our hypothesis was that population movements are a prominent driving 58 force for dengue diffusion locally. We investigated the case of Campinas, a 59 municipality with over 1.2 million inhabitants in Brazil that recorded dengue epidemics 60 in 2007, 2014 and 2015. Our study focused on the years 2007 to 2015, comprising 61 more than 114 thousand cases, geocoded to the household address, and combined 62 with socioeconomic, environmental and daily population mobility data. Our results 63showed that even controlling for demographic and environmental factors, population 64 mobility was the most important predictor for dengue fever incidence. 90 is in course in the municipality [11]. Therefore, DENV remains a public health 91 challenge in Campinas. 92While soc...