This long-term follow-up of tuberculosis sanatorium patients in the pre-chemotherapy shows the large difference between case fatality from sputum smear-positive ("open" tuberculosis) and sputum smear-negative ("closed" tuberculosis).
Similar to the previous studies, fatality from sputum smear-positive tuberculosis approximates 80%, while that of sputum smear-negative tuberculosis does not exceed 20%. During the first year following diagnosis of the latter, fatality is virtually nil.
