Tap water: A possible source of nontuberculous mycobacterial infection in patients with T cell deficiency

•Nontuberculous mycobacteria are an infectious threat to patients with lymphopenia. •Tap water is a potential source of infection, both in the community and the hospital. •Proper infectious prophylaxis in lymphopenic patients should include avoidance of tap water. Five patients, all with severe T cell dysfunction, had invasive non-tuberculous mycobacteria (NTM) infections diagnosed over a 16 month period, with four meeting Centers for Disease...