title: A comparative analysis of Chikungunya and Zika transmission.
abstract: The recent global dissemination of Chikungunya and Zika has fostered public health concern worldwide. To better understand the drivers of transmission of these two arboviral diseases, we propose a joint analysis of Chikungunya and Zika epidemics in the same territories, taking into account the common epidemiological features of the epidemics: transmitted by the same vector, in the same environments, and observed by the same surveillance systems. We analyse eighteen outbreaks in French Polynesia and the French West Indies using a hierarchical time-dependent SIR model accounting for the effect of virus, location and weather on transmission, and based on a disease specific serial interval. We show that Chikungunya and Zika have similar transmission potential in the same territories (transmissibility ratio between Zika and Chikungunya of 1.04 [95% credible interval: 0.97; 1.13]), but that detection and reporting rates were different (around 19% for Zika and 40% for Chikungunya). Temperature variations between 22°C and 29°C did not alter transmission, but increased precipitation showed a dual effect, first reducing transmission after a two-week delay, then increasing it around five weeks later. The present study provides valuable information for risk assessment and introduces a modelling framework for the comparative analysis of arboviral infections that can be extended to other viruses and territories.
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, INSERM, Institut Pierre Louis d'Epidémiologie et de Santé Publique (IPLESP UMRS 1136), 75012 Paris, France. Electronic address: julien.riou@iplesp.upmc.fr.
authors.forename: Julien
authors.initials: J
authors.lastname: Riou
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, INSERM, Institut Pierre Louis d'Epidémiologie et de Santé Publique (IPLESP UMRS 1136), 75012 Paris, France.
authors.forename: Chiara
authors.initials: C
authors.lastname: Poletto
authors.affiliation: Sorbonne Universités, UPMC Univ Paris 06, INSERM, Institut Pierre Louis d'Epidémiologie et de Santé Publique (IPLESP UMRS 1136), 75012 Paris, France.
authors.forename: Pierre-Yves
authors.initials: PY
authors.lastname: Boëlle
mesh_terms: D065632:Chikungunya Fever / Q000453:epidemiology* / Q000635:transmission*; D058872:Epidemics / Q000706:statistics & numerical data*; D006801:Humans; D011114:Polynesia / Q000453:epidemiology; D014900:West Indies / Q000453:epidemiology; D000071244:Zika Virus; D000071243:Zika Virus Infection / Q000453:epidemiology* / Q000635:transmission*
keywords: Chikungunya virus; Multilevel analysis; Outbreak analysis; Weather; Zika virus