Google the worldwide prevalence of it. It's a common estimate. It's called latent TB. People don't have symptoms, at least not yet.
"Hematopoeitic cells, especially macrophages, have long been thought of as the primary intracellular niche for M. tuberculosis, even when the infection is present at a very low levels and the individual is asymptomatic," said Kevin Urdahl, MD, PhD, an assistant professor at Seattle Biomedical Research Institute, the country's largest independent organization devoted to the study of infectious diseases. Urdahl was not involved in the research. "However, this study shows that the bacteria also has the capacity to reside within mesenchymal stem cells, and may even persist in these cells after drug treatment. Although further studies will be needed to establish the relative importance of this niche during latent infection, the immunoprivileged nature of the bone marrow and the ability of mesenchymal stem cells to express drug efflux pumps make this an intriguing possibility that could have important clinical implications."
Guess I should get some tests done again.