Varied Presentations and Responses to Treatment of Infections Caused by Mycobacterium haemophilum in Patients with AIDS

We describe three patients with AIDS who developed clinically significant infection with Mycobacterium haemophilum. One patient had skin and bone involvement and suspected laryngeal involvement; the second had extensive abdominal adenopathy with partial bowel obstruction; and the third presented with limited skin involvement. Each patient responded transiently to antimycobacterial therapy, but disease recurred and progressed in all three cases. Recovery of M. haemophilum requires a high level of clinical suspicion and special handling of mycobacterial cultures by the microbiology laboratory, including cultivation on enriched chocolate agar or heme-supplemented media and incubation at 30°C for up to 8 weeks. Characteristic patterns of drug susceptibility for this organism have been only partially defined. Reported responses to antimycobacterial therapy in AIDS patients with M. haemophilum infection have been poor, and the optimal therapeutic regimen is not yet known. The prognosis for recovery appears to depend heavily on host-related factors, particularly the degree of immunosuppression.