Mem Inst Oswaldo Cruz, Rio de Janeiro, Vol. 108(4): 399-407, June 2013

Toxoplasmosis seroprevalence in urban rodents: a survey in Niamey, Niger

Aurélien Mercier^1*, Madougou Garba^2,3,4, Henri Bonnabau⁵, Mamadou Kane⁶, Jean-Pierre Rossi⁷, Marie-Laure Dardé^1,8, Gauthier Dobigny^2,7

1*Laboratoire de Parasitologie-Mycologie, Faculté de Médecine, Université de Limoges, Unité Mixte de Recherche 1094, Neuroépidémiologie Tropicale, Institut National de la Santé et de la Recherche Médicale, Limoges, France
2Département Formation Recherche, Centre Régional AGRHYMET, Rive Droite, Niamey, Niger 3Faculté des Sciences, Université Abdou Moumouni, Niamey, Niger 4Direction Générale de la Protection des Végétaux, Niamey, Niger
5Unité Fonctionnelle de Recherche Clinique et de Biostatistique, Service de l’Information Médicale et de l’Évaluation, Centre Hospitalier Universitaire de Limoges, Limoges, France
6Institut de Recherche pour le Développement, Centre de Biologie pour la Gestion des Populations (Unité Mixte de Recherche, Institut de Recherche pour le Développement/Institut National de Recherche Agronomique/Centre de Coopération Internationale en Recherche Agronomique pour le Développement/MontpellierSupAgro), Campus de Bel-Air, Dakar, Sénégal
7Institut National de Recherche Agronomique, Unité Mixte de Recherche 1062, Centre de Biologie pour la Gestion des Populations (Institut National de Recherche Agronomique, Institut de Recherche pour le Développement, Centre de Coopération Internationale en Recherche Agronomique pour le Développement, Montpellier SupAgro), Centre de Biologie pour la Gestion des Populations, Campus International de Baillarguet Montferrier-sur-Lez, France
8Centre Hospitalier-Universitaire Dupuytren, Centre National de Référence Toxoplasmose/Toxoplasma Biological Resource Center, Limoges, France

Abstract. A serological survey of Toxoplasma gondii was conducted on 766 domestic and peridomestic rodents from 46 trapping sites throughout the city of Niamey, Niger. A low seroprevalence was found over the whole town with only 1.96% of the rodents found seropositive. However, differences between species were important, ranging from less than 2% in truly commensal Mastomys natalensis, Rattus rattus and Mus musculus, while garden-associated Arvicanthis niloticus displayed 9.1% of seropositive individuals. This is in line with previous studies on tropical rodents – that we reviewed here – which altogether show that Toxoplasma seroprevalence in rodent is highly vari­able, depending on many factors such as locality and/or species. Moreover, although we were not able to decipher statistically between habitat or species effect, such a contrast between Nile grass rats and the other rodent species points towards a potentially important role of environmental toxoplasmic infection. This would deserve to be fur­ther scrutinised since intra-city irrigated cultures are extending in Niamey, thus potentially increasing Toxoplasma circulation in this yet semi-arid region. As far as we are aware of, our study is one of the rare surveys of its kind performed in Sub-Saharan Africa and the first one ever conducted in the Sahel.

Keywords: Toxoplasma gondii, epidemiology, zoonotic disease, Africa, Sahel

*Corresponding author: aurelien.mercier@pasteur.fr