Mycobacterium haemophilum is a mycobacterium, which belongs to the same family of bacteria as the causative agents of M. avium intracellulare (MAI) and tuberculosis also belong. It is unique in that it requires haemoglobin or haem for growth. Its natural habitat and the ways in which it is transmitted remain unknown.

It is rare even among immunosuppressed people such as people with AIDS. However, it can affect the skin, with the possibility of disseminating to the bones and to other organs.

Symptoms and diagnosis

Due to the very small number of reported cases and variable course of M. haemophilum infections, it is impossible to describe a clearly recognisable set of symptoms. Ulcerating skin lesions (especially on the extremities), joint effusions, and osteomyelitis have been reported. Lesions should be screened for mycobacteria with an acid-fast stain, and positive samples should be cultured in haemin-containing culture media at 30°C.

Treatment

No clinical trials of treatments for M. haemophilum have been conducted, and there is no standard treatment. Transient responses to combinations of anti-mycobacterial drugs (such as rifampicin, ciprofloxacin, ethambutol and clofazimine) have been reported.

The in vitro sensitivity of M. haemophilum isolates is widely variable, and susceptibility tests should be performed for each patient.

References

Armstrong D et al. Epidemiologic notes and reports: Mycobacterium haemophilum infections - New York City metropolitan area. Morbidity and Mortality Weekly Report 40(37): 636-643, 1991.

Dever LL et al. Varied presentations and responses to treatment of infections caused by Mycobacterium haemophilum in patients with AIDS. Clinical Infectious Diseases 14: 1195-1200, 1992.

Paech V et al. Remission of cutaneous Mycobacterium haemophilum infection as a result of antiretroviral therapy in a human immunodeficiency virus-infected patient. Clinical Infectious Diseases 34(7): 1017-1019, 2002.

Rogers PS et al. Case reports: disseminated Mycobacterium haemophilum infection in two patients with the acquired immunodeficiency syndrome. American Journal of Science 84(3): 640-642, 1988.

Soubani AO et al. Successful treatment of disseminated Mycobacterium haemophilum infection in a patient with AIDS. Clinical Infectious Diseases 18: 475-476, 1994.

Straus WL et al. Clinical and epidemiologic characteristics of Mycobacterium haemophilum, an emerging pathogen in immunocompromised patients. Annals of Internal Medicine 120: 118-125, 1994.