II. Epidemiology

  1. Disseminated MAC infection: 40% of North American AIDS
  2. Previously most common reported HIV Bacterial Infection
    1. Early initiation of highly active HIV Antiretrovirals have significantly reduced MAC Incidence
  3. Normal Children may develop Lymphadenitis
    1. Occurs under age 5 years
    2. Rarely affects children over age 12 years

III. Pathophysiology

  1. MAC is ubiquitous in environment (water, soil, food)
  2. Causes Tuberculosis in birds and swine
  3. Colonization by respiratory and Gastrointestinal Tracts
  4. Rarely occurs if CD4 Count >50
  5. Infection in normal children
    1. Breaks in mucus membrane
    2. Tooth Eruption

IV. Symptoms

  1. Fever
  2. Fatigue
  3. Night Sweats
  4. Wasting
  5. Gastrointestinal upset

V. Signs: Normal Children with Lymphadenitis

  1. Chronic unilateral, firm or fluctuant masses

VI. Labs

  1. Alkaline Phosphatase increased
  2. Hemoglobin or Hematocrit consistent with Anemia
  3. Culture
    1. Blood Culture
    2. Bone Marrow Aspirate
    3. Lymph Node biopsy
  4. Culture Sites not useful (may represent colonization)
    1. Sputum Culture
    2. Stool Culture
  5. Tuberculin Skin Testing
    1. Negative in 50% normal hosts (without Tuberculosis)

VII. Prevention: Prophylaxis in HIV when CD4 Count < 50 cells/mm3

  1. Indicated for CD4 Cell Count < 50 cells/mm3 (previously <100 cells/mm3)
    1. If patients have delay in starting Antiretrovirals or optimized regimen cannot be used
  2. First-line prophylaxis
    1. Azithromycin 1200 mg PO each week
      1. More effective than Rifabutin and better tolerated with fewer Drug Interactions than Clarithromycin
  3. Other prophylaxis options
    1. Combination protocol
      1. Azithromycin weekly and
      2. Rifabutin daily
    2. Rifabutin 300 mg/day
      1. Reduces the Incidence of bacteremia by 50%
      2. Risk of Uveitis from rifabutin
    3. Clarithromycin 500 mg PO bid
      1. Azithromycin is better tolerated
      2. Decreases MAC infection by 68%
      3. Produces survival benefit

VIII. Management: MAC in HIV

  1. Colonization without bacteremia
    1. Should not be treated
    2. May be candidates for prophylaxis
  2. Treatment
    1. Clarithromycin and 1-2 other active agents
      1. Prevents resistance
    2. Continue drugs for the lifetime of the patient

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Ontology: Mycobacterium avium-intracellulare Infection (C0026916)

Definition (MSH) A nontuberculous infection when occurring in humans. It is characterized by pulmonary disease, lymphadenitis in children, and systemic disease in AIDS patients. Mycobacterium avium-intracellulare infection of birds and swine results in tuberculosis.
Concepts Disease or Syndrome (T047)
MSH D015270
SnomedCT 373436002, 14009004
English Infection, Mycobacterium avium intracellulare, Infection, Mycobacterium avium-intracellulare, Infection, Mycobacterium intracellulare, Infections, Mycobacterium avium-intracellulare, Infections, Mycobacterium intracellulare, Mycobacterium avium intracellulare Infection, Mycobacterium avium-intracellulare Infection, Mycobacterium avium-intracellulare Infections, Mycobacterium intracellulare Infection, Mycobacterium intracellulare Infections, MAI INFECT, MYCOBACT INTRACELLULARE INFECT, MYCOBACT AVIUM INTRACELLULARE INFECT, INFECT MYCOBACT INTRACELLULARE, INFECT MYCOBACT AVIUM INTRACELLULARE, Infection mycobacterium avium, Mycobacterium avium-intracellulare complex infection, Mycobacterium avium-intracellulare complex infection (diagnosis), Mycobacterium avium complex, Mycobacterium avium intracellulare, MAC, Mycobacterium avium-intracellulare Infection [Disease/Finding], Mycobacterium avium intracellulare infection, Mycobacterium avium complex infection, Infection due to Mycobacterium intracellulare, Infection due to Mycobacterium intracellulare (disorder), Mycobacterium avium Complex, Mycobacterium; intracellulare, Bacillus; Battey, intracellulare; Mycobacterium, Mycobacterium Avium Infection
Italian Infezione da complesso Mycobacterium avium, Infezione da Mycobacterium avium, Infezione da Mycobacterium avium intracellulare, Infezioni da Mycobacterium intracellulare, MAC, Mycobacterium avium intracellulare, Complesso Mycobacterium avium, Infezioni da Mycobacterium avium-intracellulare
Dutch Mycobacterium avium intracellulare-infectie, Mycobacterium avium-infectie, MAC, Mycobacterium avium intracellulare, Mycobacterium avium complex, Bacillus; Battey, Mycobacterium; intracellulare, intracellulare; Mycobacterium, Mycobacterium avium complex-infectie, Infectie, intracellulaire mycobacterium-avium-, Intracellulaire mycobacterium-avium-infectie, Mycobacterium-infectie, intracellulaire
French Infection à mycobacterium avium, Infection à Mycobacterium avium intracellulare, Infection à MAC, Infection au complexe mycobacterium avium, Infections dues à Mycobacterium avium-intracellulare, Infection à Mycobacterium avium-intracellulare, Infection à Mycobacterium avium et à Mycobacterium intracellulare, Infection due à Mycobacterium avium-intracellulare, Infections dues au complexe Mycobacterium avium-intracellulare, Infection due au complexe Mycobacterium avium-intracellulare, lnfection à CMA, Infection à Mycobacterium avium intra-cellulare, Mycobactérie Avium Complexe (MAC), Mycobacterium avium intracellulaire, Infection à Mycobacterium du complexe aviaire
German Infektion mit Mycobacterium avium, Mycobacterium avium intracellulare, Mycobacterium avium Komplex, MAC, Mycobacterium avium Komplex-Infektion, Mycobacterium avium intracellulare Infektion, Mycobacterium intracellulare-Infektion
Portuguese Infecção por por Mycobacterium avium intracellulare, Infecção por Mycobacterium avium, Mycobacterium avium complex (MAC), Mycobacterium avium intracellulare, Complexo por Mycobacterium avium, Infecção por complexo mycobacterium avium, Infecção por Mycobacterium avium-intracellulare, Infecção por Mycobacterium intracellulare
Spanish Infección por Mycobacterium Avium e Intracellulare, Infección por Mycobacterium avium, Mycobacterium avium complex, Mycobacterium avium intracelular, CMA, infección por Mycobacterium intracellulare (trastorno), infección por Mycobacterium intracellulare, Infección por Complejo Mycobacterim Avium, Infección por Mycobacterium avium-intracellulare, Infección por Mycobacterium intracellulare
Japanese マイコバクテリウム・アビウム感染, マイコバクテリウム・アビウム・イントラセルラレ感染, マイコバクテリウム・アビウムコンプレックス感染, マイコバクテリウムアビウムイントラセルラレカンセン, マイコバクテリウムアビウムカンセン, マイコバクテリウムアビウムコンプレックスカンセン, マイコバクテリウム・アビウムコンプレックス, マイコバクテリウム・アビウム・イントラセルラレ, MAC, MAC, マイコバクテリウムアビウムコンプレックス, マイコバクテリウムアビウムイントラセルラレ, Mycobacterium intracellulare感染症, トリ型結核菌複合体感染症, トリ型結核菌細胞内感染症, 鳥型結核菌細胞内感染症
Swedish Mycobacterium avium-intracellulare-infektion
Czech Mycobacterium avium - intracelulární infekce, Infekce způsobená Mycobacterium avium complex, Infekce způsobená Mycobacterium avium, Infekce způsobená Mycobacterium avium intracellulare, Onemocnění způsobené Mycobacterium avium intracellulare, Mycobacterium avium complex, Onemocnění způsobené Mycobacterium avium complex
Finnish Mycobacterium avium-intracellulare -infektio
Polish Zakażenie MAI, Zakażenie Mycobacterium avium intracellulare, Zakażenie grzybobakteriami ptasimi wewnątrzkomórkowymi
Hungarian Mycobacterium avium-intracellulare fertőzés, Mycobacterium avium fertőzés, Mycobaktérium avium intracelluláris, Mycobacterium avium komplex fertőzés, MAC, Mycobaktérium avium komplex
Norwegian Mycobacterium avium-intracellulare-infeksjon