title: Imported chikungunya cases in an area newly colonised by Aedes albopictus: mathematical assessment of the best public health strategy.
abstract: We aimed to identify the optimal strategy that should be used by public health authorities against transmission of chikungunya virus in mainland France. The theoretical model we developed, which mimics the current surveillance system, predicted that without vector control (VC), the probability of local transmission after introduction of viraemic patients was around 2%, and the number of autochthonous cases between five and 15 persons per hectare, depending on the number of imported cases. Compared with this baseline, we considered different strategies (VC after clinical suspicion of a case or after laboratory confirmation, for imported or autochthonous cases): Awaiting laboratory confirmation for suspected imported cases to implement VC had no significant impact on the epidemiological outcomes analysed, mainly because of the delay before entering into the surveillance system. However, waiting for laboratory confirmation of autochthonous cases before implementing VC resulted in more frequent outbreaks. After analysing the economic cost of such strategies, our study suggested implementing VC immediately after the notification of a suspected autochthonous case as the most efficient strategy in settings where local transmission has been proven. Nevertheless, we identified that decreasing reporting time for imported cases should remain a priority.
authors.affiliation: UMI IRD/UPMC Unité de Modélisation Mathématique et Informatique des Sytèmes Complexes (UMMISCO), Bondy, France.
authors.forename: Thomas
authors.initials: T
authors.lastname: Sochacki
authors.forename: Frédéric
authors.initials: F
authors.lastname: Jourdain
authors.forename: Yvon
authors.initials: Y
authors.lastname: Perrin
authors.forename: Harold
authors.initials: H
authors.lastname: Noel
authors.forename: Marie-Claire
authors.initials: MC
authors.lastname: Paty
authors.forename: Henriette
authors.initials: H
authors.lastname: de Valk
authors.forename: Alexandra
authors.initials: A
authors.lastname: Septfons
authors.forename: Frédéric
authors.initials: F
authors.lastname: Simard
authors.forename: Didier
authors.initials: D
authors.lastname: Fontenille
authors.forename: Benjamin
authors.initials: B
authors.lastname: Roche
mesh_terms: D000330:Aedes; D000818:Animals; D065632:Chikungunya Fever / Q000191:economics* / Q000453:epidemiology / Q000517:prevention & control*; D003198:Computer Simulation; D017281:Cost of Illness; D003362:Cost-Benefit Analysis / Q000191:economics; D004196:Disease Outbreaks / Q000191:economics / Q000517:prevention & control / Q000706:statistics & numerical data; D005602:France / Q000453:epidemiology; D006291:Health Policy / Q000191:economics; D006801:Humans; D007303:Insect Vectors; D018803:Models, Economic; D015233:Models, Statistical; D015995:Prevalence; D016016:Proportional Hazards Models; D015980:Public Health Practice / Q000191:economics*; D018570:Risk Assessment / Q000379:methods; D014195:Travel / Q000191:economics
keywords: Aedes albopictus; Chikungunya; imported cases; local transmission; mathematical model