title: Drivers of Rift Valley fever epidemics in Madagascar.
abstract: Rift Valley fever (RVF) is a vector-borne viral disease widespread in Africa. The primary cycle involves mosquitoes and wild and domestic ruminant hosts. Humans are usually contaminated after contact with infected ruminants. As many environmental, agricultural, epidemiological, and anthropogenic factors are implicated in RVF spread, the multidisciplinary One Health approach was needed to identify the drivers of RVF epidemics in Madagascar. We examined the environmental patterns associated with these epidemics, comparing human and ruminant serological data with environmental and cattle-trade data. In contrast to East Africa, environmental drivers did not trigger the epidemics: They only modulated local Rift Valley fever virus (RVFV) transmission in ruminants. Instead, RVFV was introduced through ruminant trade and subsequent movement of cattle between trade hubs caused its long-distance spread within the country. Contact with cattle brought in from infected districts was associated with higher infection risk in slaughterhouse workers. The finding that anthropogenic rather than environmental factors are the main drivers of RVF infection in humans can be used to design better prevention and early detection in the case of RVF resurgence in the region.
authors.affiliation: French Agricultural Research and International Cooperation Organization for Development (Cirad), Department of Biological Systems (Bios), UMR Animals, Health, Territories, Risks, and Ecosystems (Astre), Campus International de Baillarguet, 34398 Montpellier, France; renaud.lancelot@cirad.fr.|French National Agricultural Research Center for International Development, Animal Health Department, UMR Astre, Campus International de Baillarguet, 34398 Montpellier, France.
authors.forename: Renaud
authors.initials: R
authors.lastname: Lancelot
authors.affiliation: French National Agricultural Research Center for International Development, Animal Health Department, UMR Astre, Campus International de Baillarguet, 34398 Montpellier, France.|Cirad, Bios Department, UMR Astre, 97490 Sainte Clotilde, La Réunion, France.|Centre de Recherche et de Veille sur les Maladies Émergentes de l'Océan Indien, 97490 Sainte Clotilde, La Réunion, France.
authors.forename: Marina
authors.initials: M
authors.lastname: Béral
authors.affiliation: Ministère de l'Agriculture, de l'Elevage et de la Pêche, Direction des Services Vétérinaires, Ambatofotsikely, BP 530 Antananarivo 101, Madagascar.
authors.forename: Vincent Michel
authors.initials: VM
authors.lastname: Rakotoharinome
authors.affiliation: Unité de Virologie, Institut Pasteur de Madagascar, BP 1274 Antananarivo 101, Madagascar.
authors.forename: Soa-Fy
authors.initials: SF
authors.lastname: Andriamandimby
authors.affiliation: Unité de Virologie, Institut Pasteur de Madagascar, BP 1274 Antananarivo 101, Madagascar.
authors.forename: Jean-Michel
authors.initials: JM
authors.lastname: Héraud
authors.affiliation: French Agricultural Research and International Cooperation Organization for Development (Cirad), Department of Biological Systems (Bios), UMR Animals, Health, Territories, Risks, and Ecosystems (Astre), Campus International de Baillarguet, 34398 Montpellier, France.|French National Agricultural Research Center for International Development, Animal Health Department, UMR Astre, Campus International de Baillarguet, 34398 Montpellier, France.
authors.forename: Caroline
authors.initials: C
authors.lastname: Coste
authors.affiliation: French Agricultural Research and International Cooperation Organization for Development (Cirad), Department of Biological Systems (Bios), UMR Animals, Health, Territories, Risks, and Ecosystems (Astre), Campus International de Baillarguet, 34398 Montpellier, France.|French National Agricultural Research Center for International Development, Animal Health Department, UMR Astre, Campus International de Baillarguet, 34398 Montpellier, France.
authors.forename: Andrea
authors.initials: A
authors.lastname: Apolloni
authors.affiliation: Animal Production and Health Division, Food and Agriculture Organization of the United Nations, 00153 Rome, Italy.
authors.forename: Cécile
authors.initials: C
authors.lastname: Squarzoni-Diaw
authors.affiliation: French Agricultural Research and International Cooperation Organization for Development (Cirad), Department of Biological Systems (Bios), UMR Animals, Health, Territories, Risks, and Ecosystems (Astre), Campus International de Baillarguet, 34398 Montpellier, France.|French National Agricultural Research Center for International Development, Animal Health Department, UMR Astre, Campus International de Baillarguet, 34398 Montpellier, France.|World Organization for Animal Health, 75017 Paris, France.|International Health Regulations Monitoring Procedure and Information Team, Global Capacity and Response Department, World Health Organization (WHO), 1211 Geneva 27, Switzerland.
authors.forename: Stéphane
authors.initials: S
authors.lastname: de La Rocque
authors.affiliation: Emerging and Epidemic Zoonotic Diseases, Pandemic and Epidemic Disease Department, WHO, Geneva 27, Switzerland.
authors.forename: Pierre B H
authors.identifier: 0000-0002-9482-5411
authors.initials: PB
authors.lastname: Formenty
authors.affiliation: French Agricultural Research and International Cooperation Organization for Development (Cirad), Department of Biological Systems (Bios), UMR Animals, Health, Territories, Risks, and Ecosystems (Astre), Campus International de Baillarguet, 34398 Montpellier, France.|French National Agricultural Research Center for International Development, Animal Health Department, UMR Astre, Campus International de Baillarguet, 34398 Montpellier, France.
authors.forename: Jérémy
authors.identifier: 0000-0002-1913-416X
authors.initials: J
authors.lastname: Bouyer
authors.affiliation: Department of Zoology, Environmental Research Group Oxford, Oxford OX1 3PS, United Kingdom.
authors.forename: G R William
authors.initials: GR
authors.lastname: Wint
authors.affiliation: French National Agricultural Research Center for International Development, Animal Health Department, UMR Astre, Campus International de Baillarguet, 34398 Montpellier, France.|Cirad, Bios Department, UMR Astre, 97490 Sainte Clotilde, La Réunion, France.|Centre de Recherche et de Veille sur les Maladies Émergentes de l'Océan Indien, 97490 Sainte Clotilde, La Réunion, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Cardinale
mesh_terms: D000003:Abattoirs; D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000097:blood / Q000453:epidemiology* / Q000276:immunology / Q000635:transmission; D003132:Commerce; D058872:Epidemics; D006801:Humans; D007074:Immunoglobulin G / Q000097:blood; D007075:Immunoglobulin M / Q000097:blood; D008270:Madagascar / Q000453:epidemiology; D012295:Rift Valley Fever / Q000097:blood / Q000453:epidemiology* / Q000276:immunology / Q000635:transmission; D012296:Rift Valley fever virus / Q000276:immunology; D016036:Seroepidemiologic Studies; D014887:Weather
chemical_list: D007074:Immunoglobulin G; D007075:Immunoglobulin M
keywords: El Niño; One Health; cattle trade; vector-borne infection; zoonosis