Mycobacterium avium-intracellulare infection

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Mycobacterium avium-intracellulare infection
Synonyms	Mycobacterium avium complex infection, MAC infection
Pronounce	N/A
Specialty	N/A
Symptoms	Chronic cough, fatigue, weight loss, fever, night sweats
Complications	Pulmonary disease, disseminated infection
Onset	Gradual
Duration	Long-term
Types	N/A
Causes	Mycobacterium avium complex
Risks	Immunocompromised individuals, chronic lung disease
Diagnosis	Sputum culture, chest X-ray, CT scan
Differential diagnosis	Tuberculosis, lung cancer, pneumonia
Prevention	Avoidance of contaminated water and soil
Treatment	Antibiotics such as clarithromycin, azithromycin, ethambutol, rifabutin
Medication	N/A
Prognosis	Variable, depends on immune status and treatment
Frequency	Common in HIV/AIDS patients
Deaths	N/A

Mycobacterium avium-intracellulare infection (MAI or MAC) is an infection caused by two types of nontuberculous mycobacteria: Mycobacterium avium and Mycobacterium intracellulare. These bacteria are commonly found in the environment, including soil, water, and dust. MAI primarily affects individuals with compromised immune systems, such as those with HIV/AIDS, but can also affect individuals with chronic lung diseases.

Pathophysiology

The bacteria enter the body through the respiratory or gastrointestinal tracts. Once inside, they can disseminate to various organs, including the lungs, liver, and spleen. In the lungs, MAI can cause a condition known as Mycobacterium avium complex pulmonary disease, which is characterized by chronic cough, weight loss, and fatigue.

Symptoms

Symptoms of MAI infection can vary depending on the organs affected but commonly include:

• Chronic cough
• Fever
• Night sweats
• Weight loss
• Fatigue
• Diarrhea (if the gastrointestinal tract is involved)

Diagnosis

Diagnosis of MAI infection typically involves a combination of clinical evaluation, imaging studies, and laboratory tests. Sputum cultures, blood tests, and tissue biopsies may be used to identify the presence of Mycobacterium avium or Mycobacterium intracellulare. Chest X-rays or CT scans may show characteristic changes in the lungs.

Treatment

Treatment of MAI infection usually involves a combination of antibiotics over an extended period. Commonly used antibiotics include:

• Clarithromycin or Azithromycin
• Ethambutol
• Rifabutin or Rifampin

The treatment regimen may last for 12 months or longer, depending on the severity of the infection and the patient's response to therapy.

Prevention

Preventive measures for MAI infection include avoiding exposure to potential sources of the bacteria, such as untreated water and soil. Individuals with weakened immune systems should take extra precautions to minimize their risk of infection.

Prognosis

The prognosis for individuals with MAI infection varies. Those with compromised immune systems, such as HIV/AIDS patients, may have a more challenging course of the disease. Early diagnosis and appropriate treatment are crucial for improving outcomes.

See also

• Mycobacterium avium
• Mycobacterium intracellulare
• Nontuberculous mycobacteria
• HIV/AIDS
• Mycobacterium avium complex pulmonary disease
• Sputum culture
• Chest X-ray
• CT scan
• Clarithromycin
• Azithromycin
• Ethambutol
• Rifabutin
• Rifampin

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