An inverse association between West Nile virus serostatus and avian malaria infection status

• Type of Material: Article
• Authors: Matthew C. I. Medeiros, University of Missouri-St. Louis; Tavis K. Anderson, Georgia Southern University; Jenni M. Higashiguchi, University of Missouri-St. Louis; Uriel Kitron, Emory University; Edward D. Walker, Department of Microbiology and Molecular Genetics; Jeffrey D. Brawn, University of Illinois; Bethany L. Krebs, University of Illinois; Marilyn O. Ruiz, University of Illinois; Tony L. Goldberg, University of Wisconsin; Robert E. Ricklefs, University of Missouri-St. Louis; Gabriel L. Hamer, Texas A&M University
• Language: English
• Date: 2014-09-01
• Publisher: BioMed Central
• Publication Version: Final Published Version
• Copyright Statement: © Medeiros et al.; licensee BioMed Central Ltd. 2014
• License: Creative Commons Attribution 4.0 International
• Final Published Version (URL): http://dx.doi.org/10.1186/1756-3305-7-415
• Title of Journal or Parent Work: Parasites and Vectors
• ISSN: 1756-3305
• Volume: 7
• Grant/Funding Information: Malaria screening was supported by the National Science Foundation grant DEB-054239, the Whitney Harris World Ecology Center, the St. Louis Audubon Society, the Curators of the University of Missouri, and the University of Missouri-St. Louis Dissertation Fellowship awarded to MCM.; The collection of samples in Chicago, IL and WNV screening was supported by the National Science Foundation grants EF-0429124 and EF-0840403 to UDK, JDB, TLG, MOR, and EDW.
• Keywords: Coinfection; Parasite-parasite interactions; Concurrent infection; Avian malaria; West Nile virus; Haemosporida; Concomitant infection
• Research Categories: Biology, Virology; Biology, Microbiology; Environmental Sciences

Abstract

Background: Various ecological and physiological mechanisms might influence the probability that two or more pathogens may simultaneously or sequentially infect a host individual. Concurrent infections can have important consequences for host condition and fitness, including elevated mortality risks. In addition, interactions between coinfecting pathogens may have important implications for transmission dynamics. Methods: Here, we explore patterns of association between two common avian pathogens (West Nile virus and avian malaria parasites) among a suburban bird community in Chicago, IL, USA that share mosquito vectors. We surveyed 1714 individual birds across 13 species for both pathogens through established molecular protocols. Results: Field investigations of haemosporidian and West Nile virus (WNV) infections among sampled birds yielded an inverse association between WNV serostatus and Plasmodium infection status. This relationship occurred in adult birds but not in juveniles. There was no evidence for a relationship between Haemoproteus infection and WNV serostatus. We detected similar prevalence of Plasmodium among birds captured with active WNV infections and spatiotemporally paired WNV-naïve individuals of the same species, demonstrating that the two pathogens can co-infect hosts. Conclusions: Mechanisms explaining the negative association between WNV serostatus and Plasmodium infection status remain unclear and must be resolved through experimental infection procedures. However, our results highlight potential interactions between two common avian pathogens that may influence their transmission among hosts. This is especially relevant considering that West Nile virus is a common zoonotic pathogen with public health implications. Moreover, both pathogens are instructive models in infectious disease ecology, and infection with either has fitness consequences for their avian hosts.