title: Combining contact tracing with targeted indoor residual spraying significantly reduces dengue transmission.
abstract: The widespread transmission of dengue viruses (DENV), coupled with the alarming increase of birth defects and neurological disorders associated with Zika virus, has put the world in dire need of more efficacious tools forAedes aegypti-borne disease mitigation. We quantitatively investigated the epidemiological value of location-based contact tracing (identifying potential out-of-home exposure locations by phone interviews) to infer transmission foci where high-quality insecticide applications can be targeted. Space-time statistical modeling of data from a large epidemic affecting Cairns, Australia, in 2008-2009 revealed a complex pattern of transmission driven primarily by human mobility (Cairns accounted for ~60% of virus transmission to and from residents of satellite towns, and 57% of all potential exposure locations were nonresidential). Targeted indoor residual spraying with insecticides in potential exposure locations reduced the probability of future DENV transmission by 86 to 96%, compared to unsprayed premises. Our findings provide strong evidence for the effectiveness of combining contact tracing with residual spraying within a developed urban center, and should be directly applicable to areas with similar characteristics (for example, southern USA, Europe, or Caribbean countries) that need to control localizedAedes-borne virus transmission or to protect pregnant women's homes in areas with active Zika transmission. Future theoretical and empirical research should focus on evaluation of the applicability and scalability of this approach to endemic areas with variable population size and force of DENV infection.
authors.affiliation: Department of Environmental Sciences, Emory University, Atlanta, GA 30322, USA.; Global Health Institute, Emory University, Atlanta, GA 30322, USA.
authors.forename: Gonzalo M
authors.initials: GM
authors.lastname: Vazquez-Prokopec
authors.affiliation: Tropical Public Health Unit Network, Queensland Health, Cairns, Queensland 4870, Australia.; Metro South Public Health Unit, Metro South Health, Coopers Plains, Brisbane, Queensland 4113, Australia.
authors.forename: Brian L
authors.initials: BL
authors.lastname: Montgomery
authors.affiliation: Tropical Public Health Unit Network, Queensland Health, Cairns, Queensland 4870, Australia.
authors.forename: Peter
authors.initials: P
authors.lastname: Horne
authors.affiliation: Department of Biostatistics and Bioinformatics, Rollins School of Public Health, Emory University, Atlanta, GA 30322, USA.
authors.forename: Julie A
authors.initials: JA
authors.lastname: Clennon
authors.affiliation: College of Public Health, Medical and Veterinary Sciences, James Cook University, Cairns, Queensland 4878, Australia.; Australian Institute of Tropical Health and Medicine, James Cook University, Cairns 4878, Australia.
authors.forename: Scott A
authors.initials: SA
authors.lastname: Ritchie
mesh_terms: D000330:Aedes; D000818:Animals; D001315:Australia; D003140:Communicable Disease Control / Q000379:methods*; D003715:Dengue / Q000453:epidemiology / Q000517:prevention & control / Q000635:transmission; D005260:Female; D006801:Humans; D007306:Insecticides / Q000494:pharmacology*; D008297:Male; D010571:Pest Control / Q000379:methods*; D011247:Pregnancy; D011251:Pregnancy Complications, Infectious / Q000453:epidemiology / Q000517:prevention & control
chemical_list: D007306:Insecticides
keywords: Aedes aegypti; Vector control; human mobility; insecticide; transmission chain; transmission heterogeneity