DYNAMICS OF TUBERCULOSIS UNDER DOTS STRATEGY

Tuberculosis still remains as a serious public health problem. Thinking about more efficient interventions for its combat and control WHO advocates that DOTS (Directly Observed Short-time Treatment Strategy) can improve cure rates and case detection. In this context, mathematical modeling can be used to evaluate the behavior of tuberculosis under DOTS, supplying informations to optimal action strategies. The model presented in this work, describes the dynamic of 4 individuals groups: susceptibles, never before infected; latently-infected or cured of TB under chemotherapy; infectious individuals with pulmonary TB and sputum smear positive; and noninfectious with pulmonary TB but sputum-smear negative or extra-pulmonary TB. Individuals, who complete treatment successfull, are cured of tuberculosis but remain infected and individuals, who do not complete treatment, continue with the illness (infectious or noninfectious). The model, as considered here allows us to evaluate the effect of improve cure rates and case detection. The Effective Reproductive Rate was found for this model and used as epidemiological measure of severity of an epidemics. If , an epidemics occurs and if , it is eradicated. The time-dependent uncertainty analysis is presented using the Monte Carlo Method.