Gastrointestinal infections in the immunocompromised host

Immunocompromised patients, including patients with AIDS, solid organ and bone marrow transplant recipients, patients with leukemia and lymphoma, patients with inherited immune deficiencies, and patients on immunosuppressive therapy for a variety of disorders, are at risk for infections-particularly opportunistic infections, which, by definition, do not infect the healthy host. All systems of the body, including the gastrointestinal tract, are susceptible. The esophagus, stomach, small intestine, and large intestine are sites of infection for viruses, bacteria, fungi, and protozoa. Symptoms can range in severity from fevers of unknown etiology to life-threatening hemorrhage and perforation. This review summarizes recent case reports, clinical studies, and reviews pertaining to pathogens that uniquely cause disease, more frequently cause disease, or cause more severe disease in the immunocompromised host than in the immunocompetent host.