Dengue vector dynamics (Aedes aegypti) influenced by climate and social factors in Ecuador: implications for targeted control

• Published in: PloS one Vol. 8; no. 11; p. e78263
• Main Authors: Stewart Ibarra, Anna M, Ryan, Sadie J, Beltrán, Efrain, Mejía, Raúl, Silva, Mercy, Muñoz, Angel
• Format: Journal Article
• Language: English
• Published: United States Public Library of Science 12.11.2013; Public Library of Science (PLoS)
• Subjects: Aedes - physiology; Aedes aegypti; Analysis; Animals; Aquatic insects; Climate; Climate change; Climate models; Collaboration; Containers; Culicidae; Dengue; Dengue - transmission; Dengue fever; Diptera; Disease control; Disease transmission; Dynamics; Ecological effects; Ecological monitoring; Ecological studies; Ecology; Ecuador; Environmental science; Epidemics; Epidemiology; Fever; Genetic vectors; Households; Human behavior; Hydrology; Insect Vectors - physiology; Medical research; Minimum temperatures; Mosquitoes; Oviposition; Population; Population biology; Population dynamics; Prediction models; Public health; Rain; Rainfall; Risk analysis; Risk factors; Social aspects; Social factors; Storage; Storage containers; Studies; Surveys; Temperature; Temperature perception; Vector-borne diseases; Vectors (Biology); Viral diseases; Virus diseases; Viruses; Water shortages; Water storage; Ecuador; Brazil; Venezuela; New York; Rio de Janeiro Brazil; United States > US
• ISSN: 1932-6203; 1932-6203
• DOI: 10.1371/journal.pone.0078263

Dengue fever, a mosquito-borne viral disease, is now the fastest spreading tropical disease globally. Previous studies indicate that climate and human behavior interact to influence dengue virus and vector (Aedes aegypti) population dynamics; however, the relative effects of these variables depends on local ecology and social context. We investigated the roles of climate and socio-ecological factors on Ae. aegypti population dynamics in Machala, a city in southern coastal Ecuador where dengue is hyper-endemic. We studied two proximate urban localities where we monitored weekly Ae. aegypti oviposition activity (Nov. 2010-June 2011), conducted seasonal pupal surveys, and surveyed household to identify dengue risk factors. The results of this study provide evidence that Ae. aegypti population dynamics are influenced by social risk factors that vary by season and lagged climate variables that vary by locality. Best-fit models to predict the presence of Ae. aegypti pupae included parameters for household water storage practices, access to piped water, the number of households per property, condition of the house and patio, and knowledge and perceptions of dengue. Rainfall and minimum temperature were significant predictors of oviposition activity, although the effect of rainfall varied by locality due to differences in types of water storage containers. These results indicate the potential to reduce the burden of dengue in this region by conducting focused vector control interventions that target high-risk households and containers in each season and by developing predictive models using climate and non-climate information. These findings provide the region's public health sector with key information for conducting time and location-specific vector control campaigns, and highlight the importance of local socio-ecological studies to understand dengue dynamics. See Text S1 for an executive summary in Spanish.