Diarrhea and AIDS in the Era of Highly Active Antiretroviral Therapy

severe malnutrition, low-grade fever with night sweats, and, finally, a wasting away followed by death. Although multiple illness in HIV-infected patients. parasites, pathogenic bacteria, and, occasionally, viruses have been isolated from the stool of up to two-thirds of patients with AIDS, pathogen-specific therapy has generally been only Causes of Diarrhea in HIV-Infected Patients minimally effective and diarrhea generally considered a mani- Bacteria festation of the underlying immunodeficiency. Diarrhea has been described previously in association with Pathogen-specific therapy is often successful in cases where various other immunodeficiency syndromes; up to 60% of pa- pathogenic bacteria are identified. Such cases include infections tients with common variable hypogammaglobulinemia have due to Shigella, Salmonella, and Campylobacter species for diarrhea, with 40% developing malnutrition [1, 2]. In the case which treatment with the fluoroquinolones usually resolves the of severe combined immunodeficiency, patients are extremely diarrhea and fever. However, relapses after discontinuation of prone to infections and they commonly succumb to chronic therapy have been observed more frequently among HIV-indiarrhea and malabsorption. In selective IgA deficiency — the fected individuals than in the general population. A curious most common immunodeficiency state in humans that affects syndrome of nontyphoidal salmonella bacteremia that repeat1 of 500 ‐ 3,000 people in the general population — recurrent edly relapses when effective therapy is discontinued has been bronchosinusopulmonary infections are often associated with reported, a phenomenon observed in other opportunistic infeca high incidence of gastrointestinal disease, including diarrhea, tions such as cryptococcal meningitis and disseminated histosteatorrhea, and celiac sprue. plasmosis [3]. Campylobacter upsaliensis has recently been In the Western world, diarrhea has also dominated the clini- identified as a cause of chronic diarrhea in Australia [4]. cal picture of patients with advanced HIV and, in fact, has Diarrhea associated with Clostridium difficile can be a particbeen a clinical indicator of progression of immunodeficiency ularly difficult diagnostic dilemma in patients with AIDS, given along with thrush, weight loss, fevers, and night sweats. In that they are often taking various types of antibiotics and bemany cases pathogenic organisms could be isolated, and vari- cause diarrhea is so common among these patients. A C. diffious algorithms were developed to standardize the work-up of cile ‐ toxin assay should always be part of a work-up for newthis condition. However, not all cases of chronic diarrhea in onset watery diarrhea, with or without fecal leukocytes, espeadvanced AIDS can be attributed to an infectious etiology, cially if the diarrhea is associated with fever, leukocytosis, and thus the therapeutic approach is limited. Drug side effects, cramps. Treatment with metronidazole, 250 mg po t.i.d. for 7 gastrointestinal malignancies (Kaposi’s sarcoma, lymphoma), to 10 days, is usually curative. However, as in the general and HIV enteropathy are often listed as likely causes. population, up to 20% of patients will have a relapse, and these relapses should be retreated with metronidazole at the same dosage. The annual incidence of C. difficile ‐ associated diarPublication of this State-of-the-Art Clinical Article has been made possible rhea in HIV-positive individuals who were hospitalized ranged