Benthic filter feeders are able to filter a substantial amount of waterborne pathogens such as bacteria, fungi, protozoans, and viruses from a dilute solution. Arguably, this life style is highly vulnerable to disease transmission. However, some mechanisms such as dense assemblages of filter feeders should reduce infective particles in the water column sufficiently to permit the internal inactivation mechanisms to limit body burden below the infective dose level and thus, limit epizootic development. Here, we combine modeling and experimental work to demonstrate this hypothesis. We formulated a disease dynamic compartmental model and informed it using Dermo disease, caused by Perkinsus marinus, in Eastern oysters (Crassostrea virginica), as an experimental system. The model yields the basic reproduction number R0 to explore the potential of epizootic development. Preliminary 3-D simulations using the Regional Ocean Modeling System (ROMS) hydrodynamic model coupled to a benthic model, reproduces a continuous water flow, particle flux along an estuary channel, and pathogen sink due to filtration by oysters. Model results suggest that high-density oyster reefs effectively remove pathogens by refiltering water many times (overfiltration) and thus decrease the downstream pathogen flux, limiting transmission locally and in neighboring reefs. Mesocosm experiments explored Perkinsus marinus dilution (inactivation) dynamics in seawater and the effect of resource competition in oysters lowering per capita exposure to pathogens and reducing disease prevalence. Experimental results demonstrate that resource competition lowers the per capita rate of exposure of oysters to pathogens, decreasing the incidence of disease. This result confirms for non-flow conditions the overfiltration effect shown by the model. The model can be adaptable to sessile/sedentary species (e.g. bivalves, gastropods, sea urchins, corals) and to a range of hydrodynamic regimes from estuaries to lagoons and coral reefs.