Plague Circulation and Population Genetics of the Reservoir Rattus rattus: The Influence of Topographic Relief on the Distribution of the Disease within the Madagascan Focus.

• Published in: PLoS Neglected Tropical Diseases
• Main Authors: Brouat, Carine, Rahelinirina, Soanandrasana, Loiseau, Anne, Rahalison, Lila, Rajerison, Minoarisoa, Laffly, Dominique, Handschumacher, Pascal, Duplantier, Jean-Marc
• Other Authors: Centre de Biologie pour la Gestion des Populations (UMR CBGP), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut National de la Recherche Agronomique (INRA)-Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro)-Université de Montpellier (UM)-Institut de Recherche pour le Développement (IRD France-Sud )-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Unité Peste - Plague Unit Antananarivo, Madagascar, Institut Pasteur de Madagascar, Réseau International des Instituts Pasteur (RIIP)-Réseau International des Instituts Pasteur (RIIP), Laboratoire Central de la Peste (CNR), Géographie de l'environnement (GEODE), Université Toulouse - Jean Jaurès (UT2J), Université de Toulouse (UT)-Université de Toulouse (UT)-Centre National de la Recherche Scientifique (CNRS), Epidémiologie et prévention, IRD (Institut de Recherche pour le Developpement); IPM (Institut Pasteur de Madagascar); program RAMSE (Recherche appliquee a Madagascar sur la sante et l'environnement); ANR-SEST (Agence Nationale pour la Recherche, Sante-Environnement et Sante - Travail) 06 SEST 10
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2013
• Subjects: [SDV]Life Sciences [q-bio]; Rattus rattus
• Online Access: https://riip.hal.science/pasteur-00835065; https://riip.hal.science/pasteur-00835065/document; https://riip.hal.science/pasteur-00835065/file/23755317BrouatCPLoSNeglTropDis2013_7_6_e2266.pdf; https://doi.org/10.1371/journal.pntd.0002266

International audience BACKGROUND: Landscape may affect the distribution of infectious diseases by influencing the population density and dispersal of hosts and vectors. Plague (Yersinia pestis infection) is a highly virulent, re-emerging disease, the ecology of which has been scarcely studied in Africa. Human seroprevalence data for the major plague focus of Madagascar suggest that plague spreads heterogeneously across the landscape as a function of the relief. Plague is primarily a disease of rodents. We therefore investigated the relationship between disease distribution and the population genetic structure of the black rat, Rattus rattus, the main reservoir of plague in Madagascar. METHODOLOGYPRINCIPAL FINDINGS: We conducted a comparative study of plague seroprevalence and genetic structure (15 microsatellite markers) in rat populations from four geographic areas differing in topology, each covering about 150-200 km(2) within the Madagascan plague focus. The seroprevalence levels in the rat populations mimicked those previously reported for humans. As expected, rat populations clearly displayed a more marked genetic structure with increasing relief. However, the relationship between seroprevalence data and genetic structure differs between areas, suggesting that plague distribution is not related everywhere to the effective dispersal of rats. CONCLUSIONSSIGNIFICANCE: Genetic diversity estimates suggested that plague epizootics had only a weak impact on rat population sizes. In the highlands of Madagascar, plague dissemination cannot be accounted for solely by the effective dispersal of the reservoir. Human social activities may also be involved in spreading the disease in rat and human populations.