## 4 Discussion  
The sampling sessions performed during our study revealed the presence of several small mammal species circulating in the Faladjie and/or Bougouni areas, including _M. erythroleucus_, _M. natalensis_, _R. rattus_, _P. daltoni_, _G. sambianus_, _T. gracilis_, _Crocidura cf olivieri_, _Atelerix cf albiventriis_ and _Crocidua_ spp. Among them, three species were found in both areas (_M. erythroleucus_, _M. natalensis_, _P. daltoni_) and five other species (_R. rattus_, _G. sambianus_, _T. gracilis_, _C. cf olivieri_, _A. cf abiventriis_) associated with the genus _Crocidura_ spp. were captured either in Faladje or in Bougouni. The variation in relative abundance between the Faladjie and Bougouni stands of small mammals was significant. _Mastomys erythroleucus_ was the most dominant (57.33%, 43/75) in the Faladje stand and _R. rattus_ dominated (37.5%, 18/48) in that of Bougouni. These differences in variation in relative abundance between the two sites could be explained by the sites' eco-climatic characteristics; Faladje is a rural village and Bougouni is a semi-urban setting. Other factors such as anthropogenic pressure, small mammal control measures and the number of cats may have an impact on the composition and the number of circulating rodents and insectivores in endemic areas; we did not investigate these factors during the survey. A classical pressure in rural areas is children's practice of hunting small mammals. In Benin, 20.8% of gray rats were found to be infected with Bartonella spp., and none of the black rats analyzed were positive [22]. _Bartonella_ spp. was reported to infect rodents, cats and dogs in South Africa, with a high prevalence of infection in HIV-positive patients [23]. The seroprevalence of bartonellosis in the general population of the Democratic Republic of Congo was 4.5% in 2011 [21]. These data show that the transmission of _Bartonella_ spp. to humans occurs and immunocompromised patients may be at a higher risk of contamination. In Tanzania, a total of 12 (3.1%) of 382 (95% CI: 1.6-5.4) small mammal spleens were positive for _C. burnetii_ DNA. _Coxiella burnetii_ DNA was detected in _R. rattus_, _M. musculus_, _A. wilson_, _P. flavovottis_ and _A. albiventris_. Among those, eleven of twelve (91.7%, 95% CI: 61.5-99.8) _C. burnetii_ DNA-positive small mammals were trapped within Moshi Urban District [24]. In Mali, PCR revealed a low prevalence of _Coxiella burnetii_ carriage in febrile patients who tested negative using malaria Paracheck(r) rapid diagnostic tests (RDTs) [25]. These findings highlight a possible risk of transmission of these emerging pathogens to humans in rural areas in Mali and urban areas in Tanzania. Differences in the pathogen species and distribution between the Bougouni and Faladje could be explained by factors such as eco-climatic characteristics. The eco-climatic parameters may also play a role on emerging pathogen species carriage of small mammals; in Mali, _R. rattus_ in rural areas was not infected by _Bartonella_ spp. and _Coxiella burnetii_, while _R. norvegicus_ was infected by _Bartonella_ spp. in urban areas [16]. Of these infectious diseases cited above, it is particularly important to note that all of the small mammal species captured have been previously found to be naturally infected with _Borrelia crocidurae_, the pathogen of tick-borne relapsing fever boreliosis that us endemic in West African countries (Senegal, Mali, Mauritania and the Gambia). Borreliosis is also common in North Africa (Morocco, Algeria and Tunisia), with a high prevalence of Borrelia infections in small rodents and insectivores and Ornithodoros tick vectors [26]. _Mastomyms natalensis_, frequently captured in both sites, seems to be the principal reservoir of the Lassa virus in West Africa [27]. Other small rodents like _P. daltoni_ and _M. erythrolocus_,identified as carriers of LASV IgG in Guinea, are involved in the transmission of the Lassa virus (LASV) to humans [27]. _Rattus rattus_ and _Crocidura_ spp. were found to be positive for LASV IgG in Nigeria [4].