Graphical analysis of evolutionary trade-off in sylvatic Trypanosoma cruzi transmission modes

Abstract

Evolutionary trade-off (one attribute increasing at the expense of another) is a central notion in the evolution of traits, well-studied especially in life-history theory, where a framework first developed by Levins illustrates how internal (genetics) and external (fitness landscapes) forces interact to shape an organism's ongoing adaptation. This manuscript extends this framework to the context of vector-borne pathogens, with the example of Trypanosoma cruzi (the etiological agent of Chagas' disease) adapting via trade-off among three different infection routes to hostsstercorarian, vertical, and oral-in response to an epidemiological landscape that involves both hosts and vectors. Using a fitness measure derived from an invasion reproductive number, this study analyzes several different trade-off scenarios in cycles involving raccoons or woodrats, and finds that selection favors oral transmission to raccoons but classical stercorarian transmission to woodrats even under the same predation rate, with vertical (congenital) transmission favored only when aligned with dominant oral transmission or (at trace levels) under a weak trade-off.

The Evolution of Plasmid Transfer Rate in Bacteria and Its Effect on Plasmid Persistence

“…The evolution of transfer rates was first explored in the context of host-parasite modelling (Cressler et al, 2016;Kribs-Zaleta, 2014;Lipsitch and Levin, 1997;Lipsitch et al, 1996;Misevic et al, 2013) which is appropriate when plasmids are viewed as infectious replicators, exerting a cost on their host cells. These models identified conditions favouring vertical versus horizontal transmission (e.g.…”

Effectiveness of fluralaner treatment regimens for the control of canine Chagas disease: A mathematical modeling study

“…Models investigating sylvatic transmission cycles have been developed to incorporate the multiple sylvatic hosts available, advancing our understanding of interactions between hosts, vectors, and T. cruzi and highlighting both vector-fecal and oral transmission pathways [42,51,52,53,54,55,56,57]. In peridomestic settings where dogs are the main hosts, host-targeted interventions may provide a valuable tool to reduce triatomine populations and canine exposure to T. cruzi.…”

Sylvatic Transmission of Trypanosoma cruzi Among Domestic and Wildlife Reservoirs in Texas, USA: A Review of the Historical Literature

“…Sylvatic transmission occurs within the wildlife population primarily via sylvatic triatomine species that have adapted to living in animal nests (Bern et al., ). Some unique transmission sources to domestic and wild mammals include oral and vertical transmission, with consumption of contaminated bugs thought to be a significant source of infection for many species of wild and domestic animal (Roellig et al., ; Rodriguez‐Morales et al., ; Kribs‐Zaleta, ). The combination of vector and alternate modes of transmission has allowed for a robust sylvatic transmission cycle to be established in endemic regions of the Americas.…”