Myxozoans on the move: Dispersal modes, exotic species and emerging diseases

Abstract

Increased global connectivity and shorter transportation times translate to a higher probability and frequency that hosts and their parasites will be introduced to foreign locations and will arrive viable. However, myxozoans are heteroxenous with two obligatory hosts and two free-living life stages, so even if a parasite is introduced, a myriad of factors must align for establishment to occur. Associated with successful introductions are ecological and economic impacts. Unless there is an established monitoring program, it is difficult to detect the emergence of a myxozoan before clinical signs become overt. In this chapter we examine features of myxozoan parasites that promote or impede dissemination and establishment. We present examples of modes of myxozoan introduction and dispersal, both natural and human-mediated. We review known and novel species responsible for emerging diseases, and recently identified species that have the potential to cause disease. We conclude by outlining strategies to understand and limit myxozoan introductions.