Pulmonary Mycobacterium xenopi infection in non-HIV-infected patients: a systematic review.

SETTING: The incidence of Mycobacterium xenopi infections is increasing worldwide. The characteristics and optimal management of patients with pulmonary M. xenopi infections have not been well established.
METHODS: Systematic review of English- and French-language studies reporting at least two cases of microbiologically confirmed M. xenopi lung infection. Studies were independently reviewed by two reviewers. We described the risk factors and clinical presentation of advanced infection, and examined the impact on clinical success and mortality of including individual antimycobacterial drugs in the treatment regimen.
RESULTS: A total of 48 studies reporting on 1255 subjects were included. The majority were retrospective case series. There was marked heterogeneity among the studies. Patients were generally middle-aged men with a history of obstructive lung disease or prior tuberculosis, presenting with an upper lobe cavitary infection. There was no clear association between administration of particular drugs and clinical success or mortality.
CONCLUSION: We could not demonstrate any advantage of specific drugs in the treatment of pulmonary M.xenopi infection. Observations from the pooled data are likely subject to significant confounding and selection biases. The inability to make firm conclusions on the optimal management of this increasingly common infection strongly underscores the need for further research.