Why you should ask your patients about their fishing hobbies.

Patients who use immunosuppressive agents, in particular medication that blocks tumour necrosis factor-a, are at risk for mycobacterial infections. Besides the typical Mycobacterium tuberculosis infection, a lso a typical mycobacterial disease may occur. Here we demonstrate two patients with such atypical mycobacterial infection due to swimming and fishing water contact. We propose that patients, before starting with immunosuppressive therapy, are counselled about risk factors for mycobacterial disease.