Early therapy for latent tuberculosis infection

The risk of developing active tuberculosis is highest within the first 2 ye ars of infection. Therefore, an intervention that targets persons with rece nt infection, such as identifying contacts of active cases, could be partic ularly effective as an epidemic control measure. A mathematical model of a tuberculosis epidemic is formulated and used to evaluate the strategy of ta rgeting therapy to persons with recently acquired latent tuberculosis infec tion. The model is used to quantify the effectiveness of therapy for early latent tuberculosis infection in reducing the prevalence of active tubercul osis. The model is also used to demonstrate how effective therapy for early latent tuberculosis infection has to be to eliminate tuberculosis, when us ed in conjunction with therapy for active tuberculosis. Analysis of the mod el suggests that programs such as contact investigations, which identify an d treat persons recently infected with Mycobacterium tuberculosis, may have a substantial effect on controlling tuberculosis epidemics.