Reconstruction of Rift Valley fever transmission dynamics in Madagascar: Estimation of force of infection from seroprevalence surveys using Bayesian modelling

Olive Marie-Marie, Grosbois Vladimir, Tran Annelise, Nomenjanahary Lalaina Arivony, Rakotoarinoro Mihaja, Andriamandimby Soa Fy, Rogier Christophe, Héraud Jean Michel, Chevalier Véronique. 2017. Reconstruction of Rift Valley fever transmission dynamics in Madagascar: Estimation of force of infection from seroprevalence surveys using Bayesian modelling. Scientific Reports, 7:39870, 10 p.

https://doi.org/10.1038/srep39870

Article de revue ; Article de recherche ; Article de revue à facteur d'impact Revue en libre accès total

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Quartile : Q1, Sujet : MULTIDISCIPLINARY SCIENCES

Résumé : The force of infection (FOI) is one of the key parameters describing the dynamics of transmission of vector-borne diseases. Following the occurrence of two major outbreaks of Rift Valley fever (RVF) in Madagascar in 1990–91 and 2008–09, recent studies suggest that the pattern of RVF virus (RVFV) transmission differed among the four main eco-regions (East, Highlands, North-West and South-West). Using Bayesian hierarchical models fitted to serological data from cattle of known age collected during two surveys (2008 and 2014), we estimated RVF FOI and described its variations over time and space in Madagascar. We show that the patterns of RVFV transmission strongly differed among the eco-regions. In the North-West and Highlands regions, these patterns were synchronous with a high intensity in mid-2007/mid-2008. In the East and South-West, the peaks of transmission were later, between mid-2008 and mid-2010. In the warm and humid northwestern eco-region favorable to mosquito populations, RVFV is probably transmitted all year-long at low-level during inter-epizootic period allowing its maintenance and being regularly introduced in the Highlands through ruminant trade. The RVF surveillance of animals of the northwestern region could be used as an early warning indicator of an increased risk of RVF outbreak in Madagascar.

Mots-clés Agrovoc : Virus de la fièvre de la vallée du Rift, épidémiologie, modèle mathématique, sérologie, modèle de simulation, transmission des maladies, infection, fièvre de la Vallée du Rift

Mots-clés géographiques Agrovoc : Madagascar

Mots-clés libres : Rift Valley fever, Madagascar, Bayesian modelling, Force of infection

Classification Agris : L73 - Maladies des animaux
U10 - Informatique, mathématiques et statistiques

Champ stratégique Cirad : Axe 4 (2014-2018) - Santé des animaux et des plantes

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