CD34 and tuberculosis: This insight resonates with classical understandings of tuberculosis pathophysiology, which held bacillary load to be the major determinant of disease severity.15, 17 Early 20th century tuberculosis pathologists understood blood stream dissemination to be characteristic in the natural history of symptomatic and asymptomatic post primary tuberculosis; more recently investigators have shown that tuberculosis can be detected in CD34-positive cells recovered from peripheral blood during latent infection.28