From the Guidelines
Mycobacterium avium-intracellulare (MAI) infection refers to a type of bacterial infection caused by the Mycobacterium avium complex (MAC), which includes M. avium and M. intracellulare, and is a common cause of disseminated disease in individuals with advanced HIV infection. The MAC is a type of nontuberculous mycobacteria (NTM) that can cause a range of diseases, from pulmonary to disseminated infections, particularly in immunocompromised individuals 1.
Key Characteristics of MAI Infection
- MAI infection is most commonly seen in individuals with advanced HIV infection, with CD4 T-cell counts less than 50 cells/μL 1.
- The infection can cause a range of symptoms, including fever, night sweats, weight loss, and respiratory symptoms such as cough and shortness of breath.
- The diagnosis of MAI infection is typically made through a combination of clinical evaluation, laboratory tests, and imaging studies.
Treatment and Prevention of MAI Infection
- The treatment of MAI infection typically involves a combination of antibiotics, including macrolides such as clarithromycin or azithromycin, and other agents such as rifabutin or ethambutol 1.
- The use of prophylactic antibiotics, such as rifabutin, can help prevent MAI infection in individuals with advanced HIV infection 1.
- It is essential to note that the treatment and prevention of MAI infection should be individualized based on the specific needs and circumstances of each patient.
Important Considerations
- MAI infection can be severe and life-threatening, particularly in immunocompromised individuals, and requires prompt and effective treatment.
- The prevention of MAI infection is critical, particularly in individuals with advanced HIV infection, and can be achieved through the use of prophylactic antibiotics and other measures such as avoiding exposure to contaminated water and soil.
From the FDA Drug Label
CLINICAL STUDIES ... Endpoints included the following: ... (2) Clinically significant disseminated MAC disease, defined as MAC bacteremia accompanied by signs or symptoms of serious MAC infection, including one or more of the following: fever, night sweats, rigors, weight loss, worsening anemia, and/or elevations in alkaline phosphatase.
Mycobacterium avium-intracellulare (MAI) infection is a type of MAC (Mycobacterium avium complex) infection, which can cause clinically significant disseminated MAC disease characterized by signs and symptoms such as:
- Fever
- Night sweats
- Rigors
- Weight loss
- Worsening anemia
- Elevations in alkaline phosphatase 2
From the Research
Definition and Overview of Mycobacterium avium-intracellulare (MAI) Infection
- Mycobacterium avium-intracellulare (MAI) infection, also known as Mycobacterium avium complex (MAC) infection, is a type of bacterial infection caused by two types of bacteria: Mycobacterium avium and Mycobacterium intracellulare 3, 4, 5, 6, 7.
- MAI infection can cause a range of symptoms, including lung disease, bacteremia, and disseminated infection, particularly in individuals with weakened immune systems, such as those with AIDS 3, 4, 6, 7.
Risk Factors and Patient Populations
- Individuals with AIDS are at increased risk of developing MAI infection, particularly those with CD4+ counts less than 100 cells/mm3 3, 4, 6, 7.
- MAI infection can also cause chronic lung disease in immunocompetent patients 5, 6.
Treatment Options and Efficacy
- Treatment regimens for MAI infection typically include a combination of antibiotics, such as macrolides (e.g., clarithromycin, azithromycin), rifamycins (e.g., rifabutin, rifampin), and ethambutol 3, 4, 5, 6, 7.
- The efficacy of treatment regimens can vary depending on the specific combination of antibiotics used and the individual patient's response to treatment 3, 4, 5, 6, 7.
- Some studies have shown that combination therapy with a macrolide, ethambutol, and clofazimine can be effective in treating MAI lung disease 5.
- However, treatment regimens can be associated with adverse effects and drug interactions, particularly in patients with AIDS 3, 4, 6, 7.
Diagnosis and Susceptibility Testing
- Diagnosis of MAI infection is typically confirmed by positive sputum culture findings and radiologic findings 5.
- Susceptibility testing is important to guide treatment decisions, but solid clinical correlations have only been established for clarithromycin 7.
- Further research is needed to establish break-points for other anti-MAC agents and to improve treatment outcomes 7.