An unusual outbreak of nontuberculous mycobacteria in hospital respiratory wards: Association with nontuberculous mycobacterial colonization of hospital water supply network.

The incidence and prevalence of pulmonary nontuberculous mycobacterial (NTM) infection is increasing worldwide arousing concerns that NTM infection may become a serious health challenge. We recently observed a significant increase of NTM-positive sputa samples from patients referred to respiratory disease wards of a large tertiary hospital in Rome. A survey to identify possible NTM contamination revealed a massive presence of NTM in the hospital water supply network. After decontamination procedures, NTM presence dropped both in water pipelines and sputa samples. We believe that this observation should encourage water network surveys for NTM contamination and prompt decontamination procedures should be considered to reduce this potential source of infection.