Cytomegalovirus infection in gastrointestinal tracts of patients infected with HIV-1 or AIDS.

All gastrointestinal tract biopsy specimens from 190 patients positive for HIV-1 or with AIDS were reviewed to assess the prevalence of cytomegalovirus (CMV) infection, morphology of infected cells, and the associated histopathological features. Eighteen patients (10 (7.7%) of 129 HIV antibody positive and eight (13.1%) of 61 with AIDS) had CMV identified in 35 biopsy specimens from the following sites: oesophagus (n = 3); stomach (n = 6); small intestine (n = 4); colorectum (n = 18) and perianal area (n = 4). Eleven patients had CMV alone as the potential cause of symptoms and in seven there were coexistent pathogens or Kaposi's sarcoma. The appearance and type of infected cells at different sites was highly variable. Immunocytochemical techniques and electron microscopic examination were performed to confirm the presence of CMV antigen and CMV virus particles and to exclude the possibility of an adenovirus producing similar cytopathic changes. It is important to recognise the different morphological forms of infected cells, and the use of immunocytochemical techniques is recommended in patients at risk for CMV or in whom CMV infection is suspected.