The prognostic factors of TB are multi-factorial and are mainly dependent on the effect the source (M. tuberculosis bacteria) has (is allowed to have) on the infected individual (host). The virulence of the source as well as the immune and nutritional status of the host are paramount in determining the balance (effect) achieved. The success of medical intervention (chemotherapy) depends on timely recognition of the disease, applying an effective R/ (treatment) and preventing further spread of the disease.