andInfection in Urban Small Mammals From Cotonou, Benin, With Special Emphasis on Coinfection Patterns.

Abstract

A growing number of studies has highlighted the importance of coinfections in eco-evolutionary processes underlying host-parasite interactions and the resulting epidemiology of zoonotic agents. Small mammals, and particularly rodents, are known to be important reservoirs of many zoonotic pathogens, such asand, that are responsible for toxoplasmosis and atypical trypanosomiasis in humans, respectively. Laboratory experiments on rodent models have shown that primary infection withincreases the host sensitivity to other parasites, including, following an alteration in the immune response. However, data on potential interactions between these parasites in wild small mammals remain scarce. In this study, we determined theprevalence in 553 small mammals from four localities of Cotonou city, Benin. The results were then combined withdata previously collected for the same individuals in order to investigate the influence ofoninfection, and vice versa, using co-occurrence tests and generalized linear mixed models (GLMMs). Despite quite high overall prevalence (32.5% and 15.2% forand, respectively), we observed a clear and significant segregation between the two parasites. This may be explained by (i) differences in the species-specific receptivity and/or sensitivity of small mammal host species to infection by these two parasites, with(Rra),(Rno), and(Mna) being the main hosts of, while(Cro) and(Mus) were the main hosts for; and/or (ii) a possibly high mortality in coinfected animals in the wild. Although dedicated experimental studies are required to confirm this pattern, as they stand, our data fail to support that in nature, the infection of small mammals by one of these two parasites favors widespread infection by the second one.