Abstract and Introduction
Mycobacterium haemophilum is a nontuberculous mycobacterium that can infect immunocompromised patients. Because of special conditions required for its culture, this bacterium is rarely reported and there are scarce data for long-term outcomes. We conducted a retrospective study at Siriraj Hospital, Bangkok, Thailand, during January 2012–September 2017. We studied 21 patients for which HIV infection was the most common concurrent condition. The most common organ involvement was skin and soft tissue (60%). Combination therapy with macrolides and fluoroquinolones resulted in a 60% cure rate for cutaneous infection; adding rifampin as a third drug for more severe cases resulted in modest (66%) cure rate. Efficacy of medical therapy in cutaneous, musculoskeletal, and ocular diseases was 80%, 50%, and 50%, respectively. All patients with central nervous system involvement showed treatment failures. Infections with M. haemophilum in HIV-infected patients were more likely to have central nervous system involvement and tended to have disseminated infections and less favorable outcomes.
Mycobacterium haemophilum is a nontuberculous mycobacterium that causes localized and disseminated infections in immunocompromised patients and rarely in immunocompetent patients. It is a slow-growing, aerobic, fastidious mycobacterium that requires heme-supplemented culture medium and low temperatures of 30°C–32°C for optimal growth. Because of the special conditions required for culture, it is frequently not isolated because of use of inappropriate techniques, and thus is rarely reported in the medical literature.
The most common clinical manifestation of infection in adult patients is cutaneous disease,[3,4] either localized or as part of disseminated disease that occurs mainly in severely immunocompromised patients, such as those infected with HIV, those with autoimmune disease, or those who have undergone solid organ or stem cell transplantation.[5–10] Thus, infection with M. haemophilum should be suspected in immunocompromised patients who have unexplained skin lesions and are smear positive for acid-fast bacilli, but show negative results for routine mycobacterial culture.
There is no current standardized guideline for optimal management of patients infected with M. haemophilum. Furthermore, the long-term outcome of this infection has not been well documented. The purpose of this study was to determine clinical characteristics, treatment, and long-term outcomes for infections with M. haemophilum.
Emerging Infectious Diseases. 2019;25(9):1648-1652. © 2019 Centers for Disease Control and Prevention (CDC)