External Professor Castillo-Chavez and J. P. Aparicio use homogeneous and heterogeneous mixing models in the context of tuberculosis transmission dynamics, and explore the effects of population growth, stochasticity, clustering of contacts, and age structure on disease dynamics. Parameterized using demographic and epidemiological data, these models include a standard incidence homogenous mixing model, a non-homogeneous mixing model that incorporates ‘household’ contacts, and an age-structured model. This framework is used to assess the possible causes for the observed historical decline in tuberculosis notifications.