Waterborne, abiotic and other indirectly transmitted (W.A.I.T.) infections are defined by the dynamics of free-living pathogens and environmental reservoirs

Miles D. Miller-Dickson; Victor A. Meszaros; Francis Baffour-Awuah; Salvador Almagro-Moreno; C. Brandon Ogbunugafor

From the form of R 0 given in equation 21, one could surmise that several parameters in the formula have comparable sensitivities. We tested this directly by calculating the Partial Rank Correlation Coefficient (PRCC) for each of the parameters in the model, with respect to R 0 , based on methods used in prior studies [64] . We find that parameters related to an interaction with the environmental reservoir (the population of needles) such as k u (the fractional discard rate of uninfected needles), γ (the rate of daily injections per capita), and π N (the birthrate of new needles) are as central to HCV dynamics as traditionally considered parameters, such as π S (the birthrate of susceptibles), c (the contact or sharing rate of IDU), or µ (the combined death and cessation rate of IDU) ( Figure 5 ). This fortifies the notion that WAIT-specific properties dictate the spread of HCV, providing opportunities to explore more precise targeting by public health interventions.