Prevalence of cytomegalovirus retinitis in Tanzanians with low CD4 levels.
To determine the prevalence of cytomegalovirus virus (CMV) retinopathy among a consecutive group of Tanzanians with AIDS with CD4 count <100 cells/μl. Patients with HIV infection with CD4 count <100 cells/μl presenting consecutively to infectious disease services at two hospitals were examined by indirect ophthalmoscopy with fully dilated pupils. Additional clinical information was collected by interview and from patient files. One-hundred and fifty patients with CD4 count <100 cells/μl were examined, of whom 74 had CD4 count <50 cells/μl; 129 patients (86%) were classified as WHO stage 3 or 4. Only two patients (1.3%; 95% CI 0 to 2.3%) had CMV retinitis. This study demonstrates that AIDS patients in Tanzania do survive into the stage of severe immunosuppression, and that even among this group CMV retinitis is very uncommon. This supports previous studies reporting low prevalence of CMV where CD4 counts were not available. Differences in immune response in AIDS patients in different settings may depend on environmental exposure to specific viruses early in life.