Background: HIV infection causes a range of cognitive and behavioral symptoms that become more frequent and severe as the immune system deteriorates and symptomatic illness ensues.
Objective: To determine the impact of disease progression on cognitive abilities of Nigerian Africans who present in the HIV/AIDS clinic of the University Teaching Hospital, Benin City, Nigeria, using the CD4 levels as the measure of disease progression.
Methods: A total of 288 subjects comprising 96 randomly selected symptomatic AIDS patients, 96 randomly selected asymptomatic HIV-positive patients and 96 HIV-negative controls participated in the study. Enzyme-linked immunosorbent assay (ELISA) method was used to detect HIV infection, and CD4 levels were obtained for all subjects. The Community Screening Interview for Dementia (CSI 'D') was used to assess cognitive performance of subjects. Subjects were matched for age, sex and level of education.
Results: Each category of subjects comprised 48 males and 48 females. The mean ages were 32.94 +/- 8.0 years, 31.47 +/- 6.7 years and 33.56 +/- 7.1 years for the controls, asymptomoatic HIV-positive and symptomatic AIDS subjects respectively (p = 0.127). The mean CD4 levels were 684 +/- 44/microL (controls), 284 +/- 62/microL (asymptomatic HIV positive) and 142 +/- 36/microL (symptomatic AIDS). The mean CS1 'D' scores were 66.46 +/- 1.90 (controls), 66.31 +/- 2.14 (asymptomatic HIV positive) and 56.62 +/- 4.23 (symptomatic AIDS).
Conclusion: Cognitive abilities of HIV/AIDS patients decline as the disease progresses. This is reflected in the cognitive performances of the symptomatic AIDS patients. The lower the CD4 levels, the worse the cognitive deficits. There was, however, no significant difference in the performance of asymptomatic HIV-positive patients and the controls.