[Dynamics of Chagas infection transmission in Chile: model and simulation]

Triatoma infestans is the principal vector for Chagas disease in Chile. Although there is enough epidemiological information about human infection, the effect of vector and host (animals and man) populations interrelations over Chagas disease prevalence has not been studied. This work studies a determinist mathematical model for the dynamics of Chagas disease transmission by Triatoma infestans, relating entomological population parameters with infection propagation. The effect of invasion of susceptible animal and human populations by infected triatomine insects and the stability of Chagas disease endemic was simulated. The Ro parameter was estimated. This is a gross appraiser of the infection reproductive rate that relates triatomine insect density, bite rate and mortality. The infected population at equilibrium was estimated. The resulting endemic was highly stable with a great amount of chronic and few acute cases. There is always an acute Chagas epidemic stage after a recent invasion. The need for a threshold triatomine insect population for the genesis of an endemic is proposed.