I thought tuberculosis was cured years ago. Why is there a resurgence?

Never cured. Tuberculosis has never been cured. Its incidence and prevalence have decreased over the years due to improvement in screening methods and improvements in treatment, but nowdays resistant mycobacteria are on the rise and there are new cases brought by immigrants from outside of the us.
Did not havfe to be. Patients are underdiagnosed patients interrupt their medication doctors are sometimes undertrained.