We hereby observe four co-infection cases of pandemic influenza H1N1 and Mycobacterium tuberculosis with various clinical presentations. It may be prudent to consider M. tuberculosis co-infections when patients with pandemic influenza reveal unusual clinical features that do not improve despite appropriate treatments against the influenza, especially in Korea, in the endemic areas of M. tuberculosis.
Keywords: Coinfection; Influenza A Virus, H1N1 Subtype; Mycobacterium tuberculosis.