Age-Structured Core Group Model and its Impact on STD Dynamics

The recruitment of new suceptibles into a core group of sexually-active individuals may depend on the current levels of infection within a population. We extend the formalism of Hadeler and Castillo-Chavez (1995), that includes prevalence dependent recruitment rates, to include age structure within core and noncore populations. Some mathematical results are stated but only a couple of proofs are included since our objetives are to highlight the modeling process and the dynamic possibilities. This paper concludes with an example where endemic distributions can be supported when the basic reproductive number R₀ is less than one. Systems that are capable of supporting multiple attractors are more likely to support disease re-emergence. This model is likely to support stable multiple attractors when R₀ < 1.