Dr. Vanessa Ezenwa is an Associate Professor at the University of Georgia, USA, where she holds joint appointments in the Odum School of Ecology and College of Veterinary Medicine. She received a BA in Biology from Rice University, and PhD in Ecology and Evolutionary Biology from Princeton University. Her research focuses on the ecology of infectious diseases in animal populations, with a particular focus on helminth infections in wild ruminants.
Co-infection with helminths can have profound effects on a host?s response to microbes, and an increasing number of studies are investigating the consequences of worm-microbe co-infection in laboratory settings. To better understand the dynamics of co-infection in natural systems, we used a free-ranging population of African buffalo to explore the consequences of worm infection for bovine tuberculosis (BTB). We followed 200 animals for four years to test the effects of anthelmintic treatment on individual and population-level outcomes of BTB infection. We found that de-worming had no effect on individual risk of infection, but enhanced survival of BTB-infected individuals. Histological results from BTB-positive animals suggest that deworming reduces the severity of BTB in buffalo by reducing levels of bacterial dissemination. Importantly, the contrasting effects of anthelmintic treatment on BTB infection probability and mortality translate into enhanced fitness for the pathogen (M. bovis). This study reveals the potentially complex effects anthelminthic intervention can have on non-target microbial co-infections.