Spatial effects in parasite-induced marine diseases of immobile hosts

GIMÉNEZ-ROMERO, ÀLEX; VAZQUEZ, FEDERICO; LÓPEZ, CRISTÓBAL; MATÍAS, MANUEL A.

Royal Society Open Science

Estrada

Año: 2022 vol. 9

Emerging marine infectious diseases pose a substantial threat tomarine ecosystems and the conservation of their biodiversity.Compartmental models of epidemic transmission in marinesessile organisms, available only recently, are based on non-spatial descriptions in which space is homogenized andparasite mobility is not explicitly accounted for. However, inrealistic scenarios epidemic transmission is conditioned by thespatial distribution of hosts and the parasites’ mobilitypatterns, calling for an explicit description of space. In thiswork, we develop a spatially explicit individual-based modelto study disease transmission by waterborne parasites insessile marine populations. We investigate the impact ofspatial disease transmission through extensive numericalsimulations and theoretical analysis. Specifically, the effects ofparasite mobility into the epidemic threshold and the temporalprogression of the epidemic are assessed. We show that largervalues of pathogen mobility imply more severe epidemics, asthe number of infections increases, and shorter timescales toextinction. An analytical expression for the basic reproduction~ 0 , is derived as a function ofnumber of the spatial model, Rthe non-spatial counterpart, R 0 , which characterizes atransition between a disease-free and a propagation phase, inwhich the disease propagates over a large fraction of the system.