Differences in Longevity and Temperature-Driven Extrinsic Incubation Period Correlate with Varying Dengue Risk in the Arizona–Sonora Desert Region
Kacey C. Ernst,
Kathleen R. Walker,
A Lucia Castro-Luque,
Chris Schmidt,
Teresa K. Joy,
Maureen Brophy,
Pablo Reyes-Castro,
Rolando Enrique Díaz-Caravantes,
Veronica Ortiz Encinas,
Alfonso Aguilera,
Mercedes Gameros,
Rosa Elena Cuevas Ruiz,
Mary H. Hayden,
Gerardo Alvarez,
Andrew Monaghan,
Daniel Williamson,
Josh Arnbrister,
Eileen Jeffrey Gutiérrez,
Yves Carrière,
Michael A. Riehle
Affiliations
Kacey C. Ernst
Department of Epidemiology and Biostatistics, College of Public Health, University of Arizona, Tucson, AZ 85721, USA
Kathleen R. Walker
Department of Entomology, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ 85721, USA
A Lucia Castro-Luque
Centro de Estudios en Salud y Sociedad, El Colegio de Sonora, Hermosillo 83000, Sonora, Mexico
Chris Schmidt
Institute for Health Metrics and Evaluation, University of Washington, Seattle, WA 98195, USA
Teresa K. Joy
Department of Entomology, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ 85721, USA
Maureen Brophy
Department of Entomology, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ 85721, USA
Pablo Reyes-Castro
Centro de Estudios en Salud y Sociedad, El Colegio de Sonora, Hermosillo 83000, Sonora, Mexico
Rolando Enrique Díaz-Caravantes
Centro de Estudios en Salud y Sociedad, El Colegio de Sonora, Hermosillo 83000, Sonora, Mexico
Veronica Ortiz Encinas
Veterinary Molecular Biology Laboratory, Instituto Tecnológico de Sonora, Obregon 85059, Sonora, Mexico
Alfonso Aguilera
Veterinary Molecular Biology Laboratory, Instituto Tecnológico de Sonora, Obregon 85059, Sonora, Mexico
Mercedes Gameros
Centro de Salud Urbano de Nogales, Nogales 84100, Sonora, Mexico
Rosa Elena Cuevas Ruiz
Centro de Salud Urbano de Nogales, Nogales 84100, Sonora, Mexico
Mary H. Hayden
Lyda Hill Institute for Human Resilience, University of Colorado, Colorado Springs, CO 80918, USA
Gerardo Alvarez
División de Ciencias Biológicas y de la Salud, Universidad de Sonora, Hermosillo 83000, Sonora, Mexico
Andrew Monaghan
Center for Research Data & Digital Scholarship, University of Colorado, Boulder, CO 80309, USA
Daniel Williamson
Department of Entomology, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ 85721, USA
Josh Arnbrister
Department of Entomology, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ 85721, USA
Eileen Jeffrey Gutiérrez
Divisions of Biostatistics & Epidemiology, School of Public Health, Innovative Genomics Institute, University of California Berkeley, Berkely, CA 94720, USA
Yves Carrière
Department of Entomology, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ 85721, USA
Michael A. Riehle
Department of Entomology, College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ 85721, USA
Dengue transmission is determined by a complex set of interactions between the environment, Aedes aegypti mosquitoes, dengue viruses, and humans. Emergence in new geographic areas can be unpredictable, with some regions having established mosquito populations for decades without locally acquired transmission. Key factors such as mosquito longevity, temperature-driven extrinsic incubation period (EIP), and vector–human contact can strongly influence the potential for disease transmission. To assess how these factors interact at the edge of the geographical range of dengue virus transmission, we conducted mosquito sampling in multiple urban areas located throughout the Arizona–Sonora desert region during the summer rainy seasons from 2013 to 2015. Mosquito population age structure, reflecting mosquito survivorship, was measured using a combination of parity analysis and relative gene expression of an age-related gene, SCP-1. Bloodmeal analysis was conducted on field collected blood-fed mosquitoes. Site-specific temperature was used to estimate the EIP, and this predicted EIP combined with mosquito age were combined to estimate the abundance of “potential” vectors (i.e., mosquitoes old enough to survive the EIP). Comparisons were made across cities by month and year. The dengue endemic cities Hermosillo and Ciudad Obregon, both in the state of Sonora, Mexico, had higher abundance of potential vectors than non-endemic Nogales, Sonora, Mexico. Interestingly, Tucson, Arizona consistently had a higher estimated abundance of potential vectors than dengue endemic regions of Sonora, Mexico. There were no observed city-level differences in species composition of blood meals. Combined, these data offer insights into the critical factors required for dengue transmission at the ecological edge of the mosquito’s range. However, further research is needed to integrate an understanding of how social and additional environmental factors constrain and enhance dengue transmission in emerging regions.
