Co-infection with pansensitive and multidrug-resistant strains of Mycobacterium tuberculosis.

We report a case of a 23-year-old HIV-negative man with multidrug-resistant Mycobacterium tuberculosis that became evident while he was being treated for M. tuberculosis that was sensitive to all first-line drugs. This case should alert clinicians to consider co-infection as a possible cause of recrudescent disease.