High rates of disseminated infection due to non-tuberculous mycobacteria among AIDS patients in Finland

Objective: to determine the rate of disseminated infection due to non-tuberculous mycobacteria (NTM) among Finnish AIDS patients, and to analyse the epidemiology of these infections. Methods: in a prospective cohort study HIV-infected patients with CD4 counts < 200 x 10(6)/1 were interviewed, and had mycobacterial blood cultures performed at baseline and at 6 months, then subsequently for clinical indications; autopsies were performed on patients who died. The cohort was followed at least for 24 months or to death. Water samples were collected from the homes of patients and from the environment and cultured for organisms of the Mycobacterium avium complex (MAC), Environmental and clinical isolates were compared using pulsed field gel electrophoresis (PFGE). Results: NTM infection occurred in 22 (43%) of 51, 19 isolates were Mycobacterium avium, two M. genavense and one M. intracellulare. Multivariate analysis identified urban residence (P = 0.04) and eating raw fish (P = 0.04) as independent risk factors, Molecular analysis revealed two clusters of related isolates (three M. avium, two M. genavense) among urban residents. Conclusion: AIDS patients in Finland have high rates of disseminated infection due to NTM, Clusters of identical organisms and association with urban residence suggests that these are newly acquired infections in advanced AIDS.