Which bacteria most commonly cause diarrhea in AIDS?
Campylobacter, Salmonella , and Shigella spp. and C. difficile are the most common causes of diarrhea in AIDS. Yersinia enterocolitica, Staphylococcus aureus, and Aeromonas hydrophila have also been associated with severe enterocolitis in HIV-infected patients. C. difficile colitis has become the most frequent bacterial cause of diarrhea in HIV-infected patients, perhaps because of frequent exposure to antimicrobials and requirement for hospitalization. MAC is a common pathogen in patients with advanced immunosuppression (i.e., CD4 count < 50 cells/mm 3 ). An incidence of 39% has been described when the CD4 count remains less than 10/mm 3 . Tuberculosis is most frequent in developing countries and is less likely to present with diarrhea alone, and can present at any level of immune dysfunction.