Treated infectiousness parameter (ct) appears to be redundant?

[RJSheppard]

The ct parameter doesn't appear to be used in the main model - the drug-specific relative infectiousness parameters (relative to infectiousness in diseased: cd). The ct parameter does get used in the equilibrium solution, but this should probably be replaced with the relative concentration for consistency with the model...? It would likely need to be weighted if multiple drugs are used? I was wondering if the parameter should be removed to avoid confusion. (It's also possible the use of the ct parameter in the equilibrium was a conscious choice for simplicity).