Imported chikungunya cases in an area newly colonised by Aedes albopictus: mathematical assessment of the best public health strategy

• Published in: Euro surveillance : bulletin européen sur les maladies transmissibles Vol. 21; no. 18; p. 1
• Main Authors: Sochacki, Thomas, Jourdain, Frédéric, Perrin, Yvon, Noel, Harold, Paty, Marie-Claire, de Valk, Henriette, Septfons, Alexandra, Simard, Frédéric, Fontenille, Didier, Roche, Benjamin
• Format: Journal Article
• Language: English
• Published: Sweden Centre Europeen pour la Surveillance Epidemiologique du SIDA (European Centre for the Epidemiological Monitoring of AIDS) 05.05.2016
• Subjects: Aedes; Animals; Chikungunya Fever - economics; Chikungunya Fever - epidemiology; Chikungunya Fever - prevention & control; Computer Simulation; Cost of Illness; Cost-Benefit Analysis - economics; Disease Outbreaks - economics; Disease Outbreaks - prevention & control; Disease Outbreaks - statistics & numerical data; France - epidemiology; Health Policy - economics; Humans; Insect Vectors; Insects; Mathematics; Models, Economic; Models, Statistical; Prevalence; Probability; Proportional Hazards Models; Public health; Public Health Practice - economics; Risk Assessment - methods; Travel - economics; Viruses; Chikungunya; mathematical model; local transmission; Aedes albopictus; imported cases
• ISSN: 1560-7917; 1025-496X; 1560-7917
• DOI: 10.2807/1560-7917.ES.2016.21.18.30221

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.