Pulmonary disease caused by Mycobacterium xenopi in HIV-negative patients: five year follow-up of patients receiving standardised treatment.

The literature concerning the management of pulmonary disease caused by Mycobacterium xenopi is scanty and consists of retrospective reports, mostly of small series of patients. Our aim was to document the clinical features and response to treatment of this rare but challenging disease. Patients were treated in a randomised, multi-centre trial with either rifampicin plus ethambutol or rifampicin, ethambutol and isoniazid. Clinical, bacteriological and radiological progress was monitored at set intervals for 5 years. As no differences emerged between the two groups, the results have been combined to provide this prospective survey. Forty-two patients were studied. Mean age was 65 years, three-quarters were male and two-thirds had other lung disease(s). Sputum was positive on direct smear in 62%. Cavitation was present in 81%, mostly large cavities, and disease was extensive in 38%. Despite good clinical response and little toxicity the death rate was high (69%), but less than 10% died primarily because of the M. xenopi disease. The failure of treatment/relapse rate was 12%. Only 11 (26%) were known to be alive at 5 years of whom seven (17%) were known to be cured. There was no correlation between failure of treatment/relapse and in vitro resistance. Better methods of susceptibility testing and more effective regimens are needed, but it is also evident that improved management of concomitant diseases and better general health will play a major part in increasing survival.