Here, the level β = β+ represents the value at which p*
1 hits the upper bound p = 1. Thus, for
β > β+, there is no feasible value of p that ensures a wash out of the diet-endemic problem
and we may seek another control strategy to first reduce the contact rate β to below β+ and
then apply a food association program with high enough probability of effectiveness. This
ensures an effective control of the diet-problem.