title: The effect of Wolbachia on dengue outbreaks when dengue is repeatedly introduced.
abstract: Use of the Wolbachia bacterium is a proposed new strategy to reduce dengue transmission, which results in around 390 million individuals infected annually. In places with strong variations in climatic conditions such as temperature and rainfall, dengue epidemics generally occur only at a certain time of the year. Where dengue is not endemic, the time of year in which imported cases enter the population plays a crucial role in determining the likelihood of outbreak occurrence. We use a mathematical model to study the effects of Wolbachia on dengue transmission dynamics and dengue seasonality. We focus in regions where dengue is not endemic but can spread due to the presence of a dengue vector and the arrival of people with dengue on a regular basis. Our results show that the time-window in which outbreaks can occur is reduced in the presence of Wolbachia-carrying Aedes aegypti mosquitoes by up to six weeks each year. We find that Wolbachia reduces overall case numbers by up to 80%. The strongest effect is obtained when the amplitude of the seasonal forcing is low (0.02-0.30). The benefits of Wolbachia also depend on the transmission rate, with the bacteria most effective at moderate transmission rates ranging between 0.08-0.12. Such rates are consistent with fitted estimates for Cairns, Australia.
authors.affiliation: School of Mathematical and Physical Sciences, The University of Newcastle, Australia; Department of Mathematics, Nusa Cendana University, Kupang-NTT, Indonesia. Electronic address: meksianis.ndii@uon.edu.au.
authors.forename: Meksianis Z
authors.initials: MZ
authors.lastname: Ndii
authors.affiliation: School of Mathematical and Physical Sciences, The University of Newcastle, Australia. Electronic address: David.Allingham@newcastle.edu.au.
authors.forename: David
authors.initials: D
authors.lastname: Allingham
authors.affiliation: School of Mathematical and Physical Sciences, The University of Newcastle, Australia; IBM Research - Australia, Melbourne, Australia. Electronic address: R.Hickson@UNSWalumni.com.
authors.forename: R I
authors.initials: RI
authors.lastname: Hickson
authors.affiliation: National Centre for Epidemiology and Population Health, The Australian National University, Canberra, Australia. Electronic address: kathryn.glass@anu.edu.au.
authors.forename: Kathryn
authors.initials: K
authors.lastname: Glass
mesh_terms: D000330:Aedes; D000818:Animals; D003715:Dengue / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission; D004196:Disease Outbreaks / Q000517:prevention & control*; D006801:Humans; D008962:Models, Theoretical; D010572:Pest Control, Biological; D020577:Wolbachia / Q000502:physiology*
keywords: Dengue; Importation; Seasonality; Wolbachia