A socio-ecological analysis of vulnerability to dengue fever in southern coastal Ecuador.

摘要

Dengue fever, a mosquito-borne viral disease, has increased in incidence, severity, and distribution despite intensive mosquito control campaigns. For many diseases such as dengue, we have limited empirical data on disease dynamics and drivers to inform the development of effective management strategies. To address this need, I and other researchers have proposed a social-ecological systems (SES) approach as an integrative interdisciplinary research framework. I apply this framework to identify key SES drivers and interactions that influence dengue risk in El Oro, a hyper-endemic province in southern coastal Ecuador, using the following methods: (1) statistical analysis of the influence of large-scale (i.e., El Nino) and local climate factors on interannual variability in dengue (1995-2010, El Oro); (2) a longitudinal field study (Nov. 2010-June 2011) of Aedes aegypti (dengue vector) dynamics to assess the influence of local climate; (3) household surveys to identify seasonal Ae. aegypti breeding behaviors and risk factors; (4) focus groups and surveys to identify community members' knowledge and perceptions of dengue. Field studies were conducted in two urban sites in Machala, El Oro: a central area with access to public services and a newer peripheral area with limited service access. The results of these studies indicate that dengue fever and Ae. aegypti dynamics were associated with El Nino-Southern Oscillation, rainfall, and minimum temperature, with more cases of dengue during El Nino events. Non-climate factors (e.g., housing condition, demographics, water access and storage, knowledge and perceptions) interacted with climate to influence seasonal dengue risk. We found that people faced multiple biophysical, political-institutional, and social barriers to dengue prevention, and therefore recommend that dengue interventions be framed within the greater public health concerns of the community (e.g., water quality, sewerage, garbage accumulation). The results of these studies provide information for the public health sector to more effectively manage dengue by focusing on system leverage points and developing climate-driven early warning systems and targeted vector control interventions. Ultimately, this research will inform the development of research and management strategies that utilize an SES approach to reduce the burden of infectious diseases in the context of complex global changes.