title: Epidemiology. Opposite effects of anthelmintic treatment on microbial infection at individual versus population scales.
abstract: Parasitic worms modulate host immune responses in ways that affect microbial co-infections. For this reason, anthelmintic therapy may be a potent tool for indirectly controlling microbial pathogens. However, the population-level consequences of this type of intervention on co-infecting microbes are unknown. We evaluated the effects of anthelmintic treatment on bovine tuberculosis (BTB) acquisition, mortality after infection, and pathogen fitness in free-ranging African buffalo. We found that treatment had no effect on the probability of BTB infection, but buffalo survival after infection was ninefold higher among treated individuals. These contrasting effects translated into an approximately eightfold increase in the reproductive number of BTB for anthelmintic-treated compared with untreated buffalo. Our results indicate that anthelmintic treatment can enhance the spread of microbial pathogens in some real-world situations.
authors.affiliation: Odum School of Ecology and Department of Infectious Diseases, College of Veterinary Medicine, University of Georgia, Athens, GA 30602, USA. vezenwa@uga.edu.
authors.forename: Vanessa O
authors.initials: VO
authors.lastname: Ezenwa
authors.affiliation: College of Veterinary Medicine and Department of Integrative Biology, Oregon State University, Corvallis, OR 97331, USA.
authors.forename: Anna E
authors.initials: AE
authors.lastname: Jolles
mesh_terms: D000818:Animals; D000969:Antinematodal Agents / Q000627:therapeutic use*; D002020:Buffaloes / Q000276:immunology / Q000382:microbiology / Q000469:parasitology; D002417:Cattle; D060085:Coinfection; D003141:Communicable Diseases / Q000276:immunology / Q000401:mortality* / Q000662:veterinary; D005260:Female; D005273:Fenbendazole / Q000627:therapeutic use; D056084:Genetic Fitness / Q000187:drug effects*; D006374:Helminthiasis, Animal / Q000188:drug therapy* / Q000276:immunology; D054884:Host-Pathogen Interactions / Q000187:drug effects* / Q000276:immunology; D015994:Incidence; D009163:Mycobacterium bovis / Q000187:drug effects* / Q000235:genetics / Q000502:physiology; D018417:Th1 Cells / Q000276:immunology; D014380:Tuberculosis, Bovine / Q000276:immunology / Q000401:mortality*
chemical_list: D000969:Antinematodal Agents; D005273:Fenbendazole