Acta Tropica 171 (2017) 151–158
journal homepage: www.elsevier.com/locate/actatropica

Rodent-borne Trypanosoma from cities and villages of Niger and Nigeria: A special role for the invasive genus Rattus?

C. Tatard¹, M. Garb^1,2, P. Gauthier³, K. Hima⁴, E. Artige¹, D.K.H.J. Dossou⁵, S. Gagaré⁶, G. Genson¹, P. Truc⁷, G. Dobigny³*

¹Institut National de Recherche Agronomique, Centre de Biologie pour la Gestion des Populations (CBGP), Campus International de Baillarguet, CS30016, 34988 Montferrier-sur-Lez, France
²Direction Générale de la Protection des Végétaux, Ministère de l’Agriculture et de l’Elevage, BP 323, Niamey, Niger
³Institut de Recherche pour le Développement (IRD), CBGP, France
⁴Université Abdou Moumouni, Faculté des Sciences, Département de Biologie Animale, BP 10662, Niamey, Niger
⁵Université d’Abomey-Calavi, Ecole Polytechnique d’Abomey-Calavi, Laboratoire de Recherche en Biologie Appliquée, 01BP2009, Cotonou, Benin
⁶Centre Régional Agrhymet, Département Formation Recherche, BP11011, Niamey, Niger
⁷Institut de Recherche pour le Développement (IRD), UMR IRD/CIRAD InterTryp 177, Campus International de Baillarguet, 34398 Montferrier-sur-Lez Cedex 5, France

Abstract. Although they are known to sometimes infect humans, atypical trypanosomes are very poorly documented, especially in Africa where one lethal case has yet been described. Here we conducted a survey of rodent-borne Trypanosoma in 19 towns and villages of Niger and Nigeria, with a special emphasis on Niamey, the capital city of Niger. The 1298 rodents that were captured yielded 189 qPCR-positive animals from 14 localities, thus corresponding to a 14.6% overall prevalence. Rats, especially black rats, displayed particularly elevated prevalence (27.4%), with some well sampled sites showing 40–50% and up to 68.8% of Trypanosoma-carrying individuals. Rattus were also characterized by significantly lower Ct values than in the other non-Rattus species. DNA sequences could be obtained for 43 rodent-borne Trypanosoma and corresponded to 41 T. lewisi (all from Rattus) and 2 T. microti (from Cricetomys gambianus). These results, together with data compiled from the available literature, suggest that Rattus may play a particular role for the maintaining and circulation of Trypanosoma, especially T. lewisi, in Africa. Taken into account its strong abilities to invade coastal and inland regions of the continent, we believe that this genus deserves a particular attention in regards to potentially under-looked but emerging atypical trypanosome-related diseases.

Keywords. zoonotic agents, Trypanosoma lewisi, biological invasion, commensal rodents, Africa

*Corresponding author: gauthier.dobigny@ird.f (G. Dobigny).

Mammalia 2014; 78(2): 185–189
DOI 10.1515/mammalia-2013-0042

Reproduction in urban commensal rodents: the case of Mastomys natalensis from Niamey, Niger

Madougou Garba¹ and Gauthier Dobigny^2*

¹Madougou Garba: Direction Générale de la Protection des Végétaux, Ministère de l’Agriculture, BP323, Niamey, Niger; Université Abdou Moumouni, Faculté des Sciences, BP10662, Niamey, Niger; and Centre Régional Agrhymet, Département Formation Recherche, BP11011, Niamey, Niger
^2*Gauthier Dobigny, Institut de Recherche pour le Développement, Centre de Biologie pour la Gestion des Populations (UMR IRD-INRA-Cirad-Montpellier SupAgro), Campus de Baillarguet CS30016, 34988 Montferrier-sur-Lez, France; and Centre Régional Agrhymet, Département Formation Recherche, BP11011, Niamey, Niger

Abstract. Most wild Sahelian rodents display a seasonal reproduction that is usually related to rainfall, hence resources availability. Mastomys natalensis is a well-documented and major pest rodent species. In East Africa where it occurs outdoors, the species is characterized by marked population cycles. In contrast, it is mostly associated with humans in West Africa, and appears to live strictly indoors in the Sahel. Here, we have monitored the proportions of M. natalensis juveniles and sexually active adults within the city of Niamey, Niger. Our survey clearly shows that M. natalensis reproduces all year long, with no detectable seasonality. Altogether, our data confirm that reproduction may shift from seasonal to continuous when conditions are more favorable. They also suggest that the urban environment may represent an extreme habitat where resources are permanently available. From the perspective of rodent control in Niamey, our results highlight the need for a constant management policy that should be performed by public authorities.

Keywords. Commensalism, pest rodents, Sahel, sexual activity.

*Corresponding author: gauthier.dobigny@ird.fr

Urban Ecosyst (2014) 17:573–584
DOI 10.1007/s11252-013-0336-x
  © Springer Science+Business Media New York 2013

Local perception of rodent-associated problems in Sahelian urban areas: a survey in Niamey, Niger

Madougou Garba^1,2,3, Mamadou Kane⁴, Sama Gagare¹, Ibrahima Kadaoure⁵, Ramatou Sidikou², Jean-Pierre Rossi^,6, Gauthier Dobigny⁷

1Centre Régional Agrhymet, Département Formation Recherche, BP 1011, Niamey, Niger
2Faculté des Sciences, Université Abdou Moumouni, BP 10662, Niamey, Niger
3Direction Générale de la Protection des Végétaux, Ministère de l’Agriculture, BP 323, Niamey, Niger
4Centre de Biologie pour la Gestion des Populations (CBGP, UMR IRD-INRA-Cirad-SupAgro Montpellier), Institut de Recherche pour le Développement (IRD), Campus ISRA-IRD de Dakar-Bel-Air, BP 1386, Dakar, CP 18524, Senegal
5Centre Régional Agrhymet FewsNet, BP1011, Niamey, Niger
6Institut National de Recherche Agronomique, CBGP, Campus International de Baillarguet CS30016, 34988 Montferrier-sur-Lez, France
7IRD, CBGP, Campus International de Baillarguet CS30016, 34988 Montferrier-sur-Lez, France

Abstract. Rodents are involved in the epidemiology of many pathogens and are major pests for agriculture. Local perception and beliefs about rodents and their damages is a key element of control programs. We here present the first survey focusing on the human perception of rodent-associated problems in an African town, namely Niamey, Niger. In total, 170 interviews were conducted in 18 different urban districts where rodents (Mastomys natalensis, Rattus rattus and Mus musculus) are widespread and abundant. Rodentassociated problems were mentioned in almost all instances (96.5 %). Eight different categories of rodent-induced nuisances could be recurrently identified. The most frequently cited one consists in damages on food and food stocks (63.1 %), followed by damages on houses (47.3 %), furniture (19.5 %) and clothes (16.8 %). There was no significant association between damages and districts, which means that the perception of rodent associated problems did not vary significantly across the city. Our survey strongly suggests that rodents may represent major pests not only for farmers, but also for inhabitants of towns, thus contributing to reinforce economic vulnerability. Finally, no mention of sanitary or medical problems was ever recorded during our survey, thus pointing towards an apparent absence of knowledge about the potential role of rodents in some public health issues.

Keywords: Pest rodents, Food security, Public health, West Africa, Sahelian area

*Corresponding author: gauthier.dobigny@ird.fr

PLOS One
  © 2014 Garba et al.

Spatial Segregation between Invasive and Native Commensal Rodents in an Urban Environment: A Case Study in Niamey, Niger

Madougou Garba^1,2,3, Ambroise Dalecky^4,5, Ibrahima Kadaoure⁶, Mamadou Kane⁷, Karmadine Hima², Sophie Veran⁸, Sama Gagare¹, Philippe Gauthier⁵, Caroline Tatard⁸, Jean-Pierre Rossi⁸, Gauthier Dobigny^1,5*

1Centre Régional Agrhymet, Département Formation Recherche, Niamey, Niger
2Université Abdou Moumouni, Faculté des Sciences, Niamey, Niger
3Direction Générale de la Protection des Végétaux, Ministère de l’Agriculture, Niamey, Niger
4IRD, Aix Marseille Université , LPED (UMR IRD-AMU), Marseille, France
5 IRD, CBGP (UMR IRDINRA-Cirad-SupAgro Montpellier), Campus International de Baillarguet, Montferrier-sur-Lez, France
6Centre Régional Agrhymet, USAid/Fews-Net, Niamey, Niger
7IRD, CBGP, Campus ISRA-IRD de Dakar-Bel-Air, Dakar, Senegal
8INRA, CBGP, Campus International de Baillarguet, Montferrier-sur-Lez, France

Abstract. Invasive rodents have been responsible for the diffusion worldwide of many zoonotic agents, thus representing majorthreats for public health. Cities are important hubs for people and goods exchange and are thus expected to play a pivotal role in invasive commensal rodent dissemination. Yet, data about urban rodents’ ecology, especially invasive vs. native species interactions, are dramatically scarce. Here, we provide results of an extensive survey of urban rodents conducted in Niamey, Niger, depicting the early stages of rodent bioinvasions within a city. We explore the species-specific spatial distributions throughout the city using contrasted approaches, namely field sampling, co-occurrence analysis, occupancy modelling and indicator geostatistics. We show that (i) two species (i.e. rural-like vs. truly commensal) assemblages can be identified, and that (ii) within commensal rodents, invasive (Rattus rattus and Mus musculus) and native (Mastomys natalensis) species are spatially segregated. Moreover, several pieces of arguments tend to suggest that these exclusive distributions reflect an ongoing native-to-invasive species turn over. The underlying processes as well as the possible consequences for humans are discussed.

*Corresponding author: * Email: gauthier.dobigny@ird.fr