CD4 Decay Rate as an Indicator of the Time Interval between Initial Infection and First Diagnosis among Drug-Naïve Human Immunodeficiency Virus Seropositive Individuals in Lagos, Nigeria

OBJECTIVE: The aim of this study was to determine the time interval between human immunodeficiency virus (HIV) infection and the first diagnosis among drug-naïve individuals in Badagry, Nigeria. SUBJECTS AND METHODS: A sample of 213 subjects who tested HIV positive for the first time were enrolled in this study. The HIV diagnosis was performed using Startpak® and Determine® kits, and a CD4 count was carried out using a FACS Count® flow cytometer. The mean CD4 values were determined by gender and age groups. The time interval between initial HIV infection and first testing was calculated based on the average CD4 decay rate per calendar year, and data analysis was performed using SPSS software. RESULTS: At diagnosis, the mean CD4 values showed that females recorded 270 cells/µl and males 244 cells/µl. By age range, individuals <25 years recorded 437 cells/µl, those between 25 and 40 years of age had 237 cells/µl, and those aged ≥41 years had 192 cells/µl. There was a significant difference between CD4 cell categorization and age range (p < 0.001). Subjects aged between 25 and 40 years recorded the highest distribution of all CD4 cell counts. The time interval between infection and testing for females was 8.1 years and for males 6.7 years. Within the age group <25 years the interval was 5.1 years, whilst it was 8.1 years for those aged ≥41 years. CONCLUSION: Most of the population presented for testing during the advanced stages of infection. We suggest an upscaling of HIV voluntary counseling and testing to encourage early detection and better treatment outcomes.