Emergence of disseminated infections due to nontuberculous mycobacteria in non-HIV-infected patients, including immunocompetent and immunocompromised patients in a university hospital in Taiwan

Abstract

Objectives: Although disseminated nontuberculous mycobacteria (NTM) infection has been increasingly reported in patients with AIDS, this condition is still considered rare in non-HIV-infected patients.

Methods: We retrospectively reviewed the medical records of non-HIV-infected patients treated at National Taiwan University Hospital from January 1997 to December 2004 to search for epidemiological trends in disseminated NTM infection. Data analyzed included etiology, demographic characteristics, underlying disease, initial symptoms and signs, treatment, and outcomes.

Results: Disseminated NTM infections occurred in 15 non-HIV-infected patients during the study period. The mean age of these patients was 51 years (range 13-80). Among these patients, eight were males, and eight had various immunocompromised conditions. Fever was an initial presentation in 12 patients (80%). Diagnosis was made by positive blood (seven patients) or bone marrow culture (five patients) in the majority (73%) of patients. Infectious etiologies included Mycobacterium avium complex (MAC) in eight, rapidly growing mycobacteria (RGM) in four and Mycobacterium kansasii in three. The mean time from initial presentation to initiation of anti-NTM therapy was 130 days (ranged from 9 days to 17 months). Mortality was highest in patients with M. kansasii (100%), followed by RGM (25%) and MAC (12.5%).

Conclusions: Although disseminated NTM infection is an emerging condition among patients without HIV infection, it is a condition which is associated with immune deficiency. A high level of clinical suspicion should be maintained for avoiding delayed diagnosis, especially in patients with underlying immunosuppression. Blood culture might play an important role in the early diagnosis of disseminated NTM disease. Early diagnosis can lead to appropriate diagnosis and reduce mortality.