Gastrointestinal infections in the immunocompromised host.

Infectious diseases of the gastrointestinal tract continue to be an important source of morbidity and mortality. Viruses, bacteria, fungi, and protozoa that infect normal hosts also infect the gastrointestinal tract in immunocompromised hosts. Disease caused by these pathogens may be more severe and more difficult to treat in immunocompromised hosts. In addition, pathogens that rarely cause disease in normal hosts cause significant disease in immunosuppressed hosts. Diagnostic decisions need to take into account expected pathogens and response to therapy. Treatment decisions must be based on the findings of diagnostic procedures; expected pathogens; and recent data suggesting that highly active antiretroviral therapy, with its ability to reconstitute immune function, is an essential component of treatment. This review summarizes the most important developments made in the pathogenesis, clinical presentation, diagnosis, and treatment of gastrointestinal infections in immunocompromised hosts in the past year.