The impact of multiple infections on wild animal hosts: a review

Bordes, Frédéric; Morand, Serge

At the demographic level, multiple infections are clearly prone to reduce body condition of the host, affecting survival and reproduction in birds (44Á46) and in mammals (47Á50). According to the prediction for helminthÁhelminth coinfections, wild rabbits harbouring more than three helminth species have a worse body condition compared to rabbits only infected by one or two helminths (47) , and multiple helminth infections have more deleterious impacts on body condition of the willow ptarmigan than single helminth infection (45) . Jolles and colleagues (49) investigated microparasiteÁhelminth coinfections and demonstrated that African buffaloes coinfected with Mycobacterium bovis and gastrointestinal nematodes had a reduced lifespan and a worsened body condition compared to African buffaloes infected only by bovine tuberculosis or only by digestive worms. Interestingly, nematodes facilitated tuberculosis invasion by inducing immune-suppression effects (51) . Similarly, Purple martins infected by two blood parasites, Haemoproteus prognei and an unidentified filarial nematode, had consistently higher mortality rates compared to birds infected only by the filarial nematode (45) .