Estimating the time period between infection and diagnosis based on CD4+ counts at first diagnosis among HIV-1 antiretroviral naïve patients in Nigeria.

INTRODUCTION: CD4+ T-cell levels are an important criterion for categorizing HIV-related clinical conditions. Late diagnosis of infection contributes to poor medical outcomes and the continuation of viral transmission. This population-based cohort study in north central Nigeria reports the initial CD4+ lymphocyte counts at the time of first HIV diagnosis and determines the approximate time interval when HIV infection was acquired. METHODOLOGY: Confirmed HIV-1 infected individuals (n = 588) for whom the dates of first HIV diagnosis were known were enrolled in this study. CD4+ lymphocyte counts were measured using a Fluorescence Activated Cell Sorter (FACS) platform that automatically quantifies CD4+ lymphocytes as absolute numbers of lymphocytes per µL of blood. The estimated time interval between HIV infection and time of first HIV diagnosis was determined as a function of the CD4+ lymphocytes' decay rate per calendar year. RESULTS: The results showed that 22.1% and 49.7% of HIV-infected individuals present late with advanced (CD4+: 200-349 cells/mL) and severe (CD4+: < 200 cells/mL) immunosuppression respectively, while only 12.1% present with CD4+ ≥ 500 cells/mL and 16.2%with CD4+ between 350-499 cells/mL. Mean CD4+ counts for females were higher when compared to those of males (p > 0.05), The time interval between HIV infection and first diagnosis was approximately 6.1 years for males and 7.3 years for females. CONCLUSION: The majority of HIV-infected individuals in this study accessed health care at late stages of infection, suggesting many HIV-infected individuals in Nigeria are unaware of their HIV status. More efficient programs for early diagnosis of HIV to prevent transmission are urgently required.

Urban-rural estimation of hepatitis C virus infection sero-prevalence in north Central Nigeria.

BACKGROUND/OBJECTIVE: The epidemiology of hepatitis C virus (HCV) infection has been partially described for at risk groups in urban communities in Nigeria. On the other hand, literature on the possible spread of the virus in rural Nigeria remains extremely scanty. The objective of this study was to estimate the prevalence of HCV in a rural and urban community in Nigeria. METHODS: Four hundred and twenty four (n = 424) plasma samples belonging to 238 rural inhabitants and 186 urban dwellers in North Central Nigeria were tested for anti-HCV markers using a third generation quantitative enzyme-linked immunosorbent assay (ELISA) that uses recombinant proteins and synthetic peptides derived from core and non-structural regions. RESULTS: 29(12.2%, CI = 0.17-0.86) of the rural samples and 5(2.7%, CI = 0.01-0.06) of urban samples were positive for HCV infection. The highest number of infections was in the 21-40 years age category. Our preliminary findings indicates that the number of HCV infection in rural was higher (p = 0.03) when compared with urban settings in Nigeria. CONCLUSION: Our results suggest a higher prevalence of HCV infection in rural than urban Nigeria in the region studied and possibly in Nigeria as a whole. HCV transmission is active in rural Nigeria and large scale studies to understand the dynamics of the infection are required so as to plan targeted preventive measures.