A STRUCTURED MODEL FOR THE TRANSMISSION DYNAMICS OFMYCOBACTERIUM MARINUMBETWEEN AQUATIC ANIMALS

Abstract

Mycobacterium marinum (Mm), a genetically similar bacterium to Mycobacterium tuberculosis, affects a number of fish industries (fisheries, aquaculture, aquariums and research stocks) on a comparable scale to tuberculosis (TB) in humans. Because of this, and the practical advantages of working with animal models as opposed to humans, Mm infections in recently established fish models provide a unique opportunity for the study of mycobacterial infections. We derive a model of transmission dynamics of Mm in fish, which either involves consumption of an infected host or a source of bacteria to ensure "activation" into a highly infectious state. We derive a model of transmission within a food web, in which infected fish behavior is structured by infection severity. This is a key component as chronic (seemingly asymptomatic) infection is prominent in both fish and human TB. We illustrate, via a novel numerical scheme, that this model can be used to reproduce experimental settings. We further argue that the framework developed herein is a useful tool to address key questions such as design in experimental settings and potential control strategies in large-scale situations.