Multiple transmission routes sustain high prevalence of a virulent parasite in a butterfly host. Issue 1910 (4th September 2019)

• Record Type: Journal Article
• Authors: Majewska, Ania A.; Sims, Stuart; Schneider, Anna; Altizer, Sonia; Hall, Richard J.
• Is Part Of: Proceedings. Volume 286:Issue 1910(2019)
• Publication Date: 2019-09-04
• Subjects: vertical and horizontal transmission -- environmental transmission -- host–parasite dynamics -- Ophryocystis elektroscirrha -- monarch butterfly -- Danaus plexippus; Biology -- Periodicals; 570.5
• DOI: 10.1098/rspb.2019.1630
• Languages: English
• ISSNs: 0962-8452

Abstract

Abstract : Understanding factors that allow highly virulent parasites to reach high infection prevalence in host populations is important for managing infection risks to human and wildlife health. Multiple transmission routes have been proposed as one mechanism by which virulent pathogens can achieve high prevalence, underscoring the need to investigate this hypothesis through an integrated modelling-empirical framework. Here, we examine a harmful specialist protozoan infecting monarch butterflies that commonly reaches high prevalence (50–100%) in resident populations. We integrate field and modelling work to show that a combination of three empirically-supported transmission routes (vertical, adult transfer and environmental transmission) can produce and sustain high infection prevalence in this system. Although horizontal transmission is necessary for parasite invasion, most new infections post-establishment arise from vertical transmission. Our study predicts that multiple transmission routes, coupled with high parasite virulence, can reduce resident host abundance by up to 50%, suggesting that the protozoan could contribute to declines of North American monarchs.