title: A sero-epidemiological study of arboviral fevers in Djibouti, Horn of Africa.
abstract: Arboviral infections have repeatedly been reported in the republic of Djibouti, consistent with the fact that essential vectors for arboviral diseases are endemic in the region. However, there is a limited recent information regarding arbovirus circulation, and the associated risk predictors to human exposure are largely unknown. We performed, from November 2010 to February 2011 in the Djibouti city general population, a cross-sectional ELISA and sero-neutralisation-based sero-epidemiological analysis nested in a household cohort, which investigated the arboviral infection prevalence and risk factors, stratified by their vectors of transmission. Antibodies to dengue virus (21.8%) were the most frequent. Determinants of infection identified by multivariate analysis pointed to sociological and environmental exposure to the bite of Aedes mosquitoes. The population was broadly naïve against Chikungunya (2.6%) with risk factors mostly shared with dengue. The detection of limited virus circulation was followed by a significant Chikungunya outbreak a few months after our study. Antibodies to West Nile virus were infrequent (0.6%), but the distribution of cases faithfully followed previous mapping of infected Culex mosquitoes. The seroprevalence of Rift valley fever virus was 2.2%, and non-arboviral transmission was suggested. Finally, the study indicated the circulation of Toscana-related viruses (3.7%), and a limited number of cases suggested infection by tick-borne encephalitis or Alkhumra related viruses, which deserve further investigations to identify the viruses and vectors implicated. Overall, most of the arboviral cases' predictors were statistically best described by the individuals' housing space and neighborhood environmental characteristics, which correlated with the ecological actors of their respective transmission vectors' survival in the local niche. This study has demonstrated autochthonous arboviral circulations in the republic of Djibouti, and provides an epidemiological inventory, with useful findings for risk mapping and future prevention and control programs.
authors.affiliation: Aix Marseille Université, IRD French Institute of Research for Development, EHESP French School of Public Health, EPV UMR_D 190 "Emergence des Pathologies Virales", Marseille, France.
authors.forename: Fred
authors.initials: F
authors.lastname: Andayi
authors.affiliation: Aix Marseille Université, IRD French Institute of Research for Development, EHESP French School of Public Health, EPV UMR_D 190 "Emergence des Pathologies Virales", Marseille, France; IHU Méditerranée Infection, APHM Public Hospitals of Marseille, Marseille, France.
authors.forename: Remi N
authors.initials: RN
authors.lastname: Charrel
authors.affiliation: Aix Marseille Université, IRD French Institute of Research for Development, EHESP French School of Public Health, EPV UMR_D 190 "Emergence des Pathologies Virales", Marseille, France; Ecole des Hautes Etudes en Santé Publique de Rennes (EHESP), Sorbonne Paris Cité, Rennes, France.
authors.forename: Alexia
authors.initials: A
authors.lastname: Kieffer
authors.affiliation: Aix Marseille Université, IRD French Institute of Research for Development, EHESP French School of Public Health, EPV UMR_D 190 "Emergence des Pathologies Virales", Marseille, France; IHU Méditerranée Infection, APHM Public Hospitals of Marseille, Marseille, France.
authors.forename: Herve
authors.initials: H
authors.lastname: Richet
authors.affiliation: Aix Marseille Université, IRD French Institute of Research for Development, EHESP French School of Public Health, EPV UMR_D 190 "Emergence des Pathologies Virales", Marseille, France; IHU Méditerranée Infection, APHM Public Hospitals of Marseille, Marseille, France.
authors.forename: Boris
authors.initials: B
authors.lastname: Pastorino
authors.affiliation: French National Reference Centre for Arboviruses, IRBA, Marseille, France.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Leparc-Goffart
authors.affiliation: Ministère de la Santé, Institut National de Santé Publique, Djibouti, Republic of Djibouti.
authors.forename: Ammar Abdo
authors.initials: AA
authors.lastname: Ahmed
authors.affiliation: INSERM UMR-S 707, Université Pierre et Marie Curie, Paris 6; Department of Public Health, Hôpital Saint-Antoine, AP-HP, Paris, France.
authors.forename: Fabrice
authors.initials: F
authors.lastname: Carrat
authors.affiliation: Ecole des Hautes Etudes en Santé Publique de Rennes (EHESP), Sorbonne Paris Cité, Rennes, France.
authors.forename: Antoine
authors.initials: A
authors.lastname: Flahault
authors.affiliation: Aix Marseille Université, IRD French Institute of Research for Development, EHESP French School of Public Health, EPV UMR_D 190 "Emergence des Pathologies Virales", Marseille, France; IHU Méditerranée Infection, APHM Public Hospitals of Marseille, Marseille, France; Ecole des Hautes Etudes en Santé Publique de Rennes (EHESP), Sorbonne Paris Cité, Rennes, France.
authors.forename: Xavier
authors.initials: X
authors.lastname: de Lamballerie
mesh_terms: D000293:Adolescent; D000328:Adult; D001102:Arbovirus Infections / Q000453:epidemiology* / Q000276:immunology; D001103:Arboviruses / Q000302:isolation & purification*; D003430:Cross-Sectional Studies; D015730:Djibouti / Q000453:epidemiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D016036:Seroepidemiologic Studies; D055815:Young Adult