Disseminated Mycobacterium “Avium” Complex


Meeting: Hospital Medicine 2016, March 6-9, San Diego, Calif.

Abstract number: 767

Categories: Adult, Clinical Vignettes Abstracts

Keywords: , , ,

Case Presentation:

36 year old female with PMHX of HIV/AIDS on HAART(concern for non-compliance) for last 10 years, CD4<40, HIV retinitis, CMV Retinitis, PCP infection presented with abdominal pain, chronic diarrhea, unintentional weight loss and deceased appetite. Initial work up revealed pancytopenia and low albumin. Infectious work up for diarrhea was negative. Non-contrast CT of the abdomen revealed bulky mesenteric lymphadenopathy with mesenteric fat stranding concerning of mesenteric lymphadenitis. Detailed chart review revealed history of untreated pulmonary Mycobacterium Avium Complex infection, hence disseminated MAC infection was high on differential along with Lymphoma, Castle’s disease, Tuberculosis and disseminated fungal infection. Ultrasound guided lymph node biopsy revealed numerous Acid fast bacilli. Bone marrow biopsy was impressive for heavy AFB burden. Endoscopy revealed whitish plaques in duodenum which were biopsied. Duodenal lesions were positive for numerous Acid fast bacilli. PCR confirmed MAC infection. Blood cultures were reported to be positive for mycobacterium as well. Unfortunately, patient continues to be non-compliant with her medications and has been requiring multiple blood transfusions for symptomatic anemia. She was started on MAC treatment regimen with Clarithromycin, Ethambutol and Rifabutin.


The incidence of disseminated MAC disease is 20% to 40% in patients with severe AIDS-associated immunosuppression, CD4 <50, in the absence of effective antiretroviral therapy (ART) or chemoprophylaxis. The overall incidence of disseminated MAC disease among HIV-infected patients has fallen more than 10-fold since the introduction of effective ART. Factors other than a CD4 count <50 cells/mm3 that are associated with increased susceptibility to MAC disease are high plasma HIV RNA levels (>100,000 copies/mL), previous Oppurtunistic Infections, previous colonization of the respiratory or gastrointestinal tract with MAC. Persistent fever and weight loss are the most common symptoms. The organism can usually be cultured from multiple sites, including blood, liver, lymph node, or bone marrow. Species identification to differentiate M.TB from MAC is done by DNA probe, high performance liquid chromatography or other biochemical tests. Abdominal computed tomography (CT) has been advocated in the diagnostic evaluation of disseminated MAC, especially to look for retroperitoneal lymphadenopathy. Prophylaxis with azithromycin is recommended for all patients with CD4 counts less than 50 cells/mL. Optimum treatment for disseminated MAC includes Clarithromycin, Ethambutol and Rifabutin.  Our case represents all the manifestations of disseminated MAC including pulmonary, lymphatic, Hematologic and Gastrointestinal. 

Conclusions: ‘Avium’ in latin stands for ‘wild’. We present a case exhibiting severe and multi-system manifestations of Mycobacterium “avium” complex in an AIDS patient.

To cite this abstract:

ROY DDK. Disseminated Mycobacterium “Avium” Complex. Abstract published at Hospital Medicine 2016, March 6-9, San Diego, Calif. Abstract 767. Journal of Hospital Medicine. 2016; 11 (suppl 1). https://www.shmabstracts.com/abstract/disseminated-mycobacterium-avium-complex/. Accessed April 3, 2020.

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