title: The Epidemiology of Rift Valley Fever in Mayotte: Insights and Perspectives from 11 Years of Data.
abstract: Rift Valley fever (RVF) is a zoonotic arboviral disease that is a threat to human health, animal health and production, mainly in Sub-Saharan Africa. RVF virus dynamics have been poorly studied due to data scarcity. On the island of Mayotte in the Indian Ocean, off the Southeastern African coast, RVF has been present since at least 2004. Several retrospective and prospective serological surveys in livestock have been conducted over eleven years (2004-15). These data are collated and presented here. Temporal patterns of seroprevalence were plotted against time, as well as age-stratified seroprevalence. Results suggest that RVF was already present in 2004-07. An epidemic occurred between 2008 and 2010, with IgG and IgM peak annual prevalences of 36% in 2008-09 (N = 142, n = 51, 95% CI [17-55]) and 41% (N = 96, n = 39, 95% CI [25-56]), respectively. The virus seems to be circulating at a low level since 2011, causing few new infections. In 2015, about 95% of the livestock population was susceptible (IgG annual prevalence was 6% (N = 584, n = 29, 95% CI [3-10])). Monthly rainfall varied a lot (2-540mm), whilst average temperature remained high with little variation (about 25-30°C). This large dataset collected on an insular territory for more than 10 years, suggesting a past epidemic and a current inter-epidemic period, represents a unique opportunity to study RVF dynamics. Further data collection and modelling work may be used to test different scenarios of animal imports and rainfall pattern that could explain the observed epidemiological pattern and estimate the likelihood of a potential re-emergence.
authors.affiliation: Centre for the Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, United Kingdom.
authors.forename: Raphaëlle
authors.initials: R
authors.lastname: Métras
authors.affiliation: UMR CMAEE, CIRAD, Sainte-Clotilde, La Réunion, France.|UMR1309 CMAEE, INRA, Montpellier, France.|Bureau de la Santé Animale, Direction Générale de l'Alimentation, Paris, France.|Université de La Réunion, St Denis, France.
authors.forename: Lisa
authors.initials: L
authors.lastname: Cavalerie
authors.affiliation: GDS Mayotte-Coopérative Agricole des Eleveurs Mahorais, Coconi, Mayotte, France.
authors.forename: Laure
authors.initials: L
authors.lastname: Dommergues
authors.affiliation: Direction de l'Alimentation, de l'Agriculture et de la Forêt de Mayotte, Mamoudzou, France.
authors.forename: Philippe
authors.initials: P
authors.lastname: Mérot
authors.affiliation: Centre for the Mathematical Modelling of Infectious Diseases, Department of Infectious Disease Epidemiology, London School of Hygiene & Tropical Medicine, London, United Kingdom.
authors.forename: W John
authors.initials: WJ
authors.lastname: Edmunds
authors.affiliation: WIDER, Warwick University, Coventry, United Kingdom.|Life Sciences, Warwick University, Coventry, United Kingdom.|Mathematics Institute, Warwick University, Coventry, United Kingdom.
authors.forename: Matt J
authors.initials: MJ
authors.lastname: Keeling
authors.affiliation: UMR CMAEE, CIRAD, Sainte-Clotilde, La Réunion, France.|UMR1309 CMAEE, INRA, Montpellier, France.
authors.forename: Catherine
authors.initials: C
authors.lastname: Cêtre-Sossah
authors.affiliation: UMR CMAEE, CIRAD, Sainte-Clotilde, La Réunion, France.|UMR1309 CMAEE, INRA, Montpellier, France.
authors.forename: Eric
authors.initials: E
authors.lastname: Cardinale
mesh_terms: D000818:Animals; D002417:Cattle; D002418:Cattle Diseases / Q000453:epidemiology / Q000821:virology*; D017507:Comoros / Q000453:epidemiology; D015511:Goat Diseases / Q000453:epidemiology / Q000821:virology*; D006041:Goats; D006801:Humans; D012189:Retrospective Studies; D012295:Rift Valley Fever / Q000453:epidemiology*