Analysis of HIV-1 sub types among blood donors in Uganda using a multi-region hybridization assay.

Abstract

BACKGROUND: Uganda has been a focus of HIV/AIDS intervention efforts, including vaccine clinical trials. HIV-1 genetic diversity poses challenges for design of efficacious vaccines. Data on HIV-1 genetic diversity is crucial for design of an effective vaccine in Uganda. Some previous studies have reported discrepant results probably due to varied sensitivity of different sub typing methods and different study populations. Also no study sampled HIV-1 across the entire country. STUDY OBJECTIVES: I. To determine the HIV-1 prevalence, II. HIV-1 sub type distribution among blood donors attending donation centres located in five different regions of Nakasero / Kampala (Central), Mbale (Eastern), Fort Portal (Western), Mbarara (Southern) and Gulu (Northern region).

METHODOLOGY: 6, 192 samples were collected from anonymous blood donors in five regional blood banks of Uganda. All samples were tested for HIV-1 using MUWRP laboratory algorithm. HIV-1 viral load and HIV-1 sub typing was performed on HIV-1 positive samples using Roche Amplicor HIV-1 monitor test v1.5 and MHA acd respectively. RESULTS: HIV-1 prevalence among blood donors was 1.3% but was highest in kampala at 1.8% and Gulu 1.5% and was lowest in Fort portal and Mbarara at 0.9% and 1.0% respectively. Prevalence increased with increasing age being 3.2% among the 34-39 and 3.4% in the 50+ age groups. HIV-1 subtypes A accounted for 50% of cases, 25% subtype D, 2% subtype C and recombinants AD made up 20% and 3% for AC. Subtype A was dominant in 4 out of 5 regional blood banks while subtype D predominated in Fort Portal. Sub type distribution was comparable across gender but the HIV-1 prevalence was higher in female (1.6%) blood donors than in males (1.3%) CONCLUSIONS: This study adds information to the HIV-1 sub type distribution in Uganda and informs vaccine design and clinical trials. HIV-1 pure sub type A was the most predominant sub type among blood donors in Uganda and the proportion of pure sub type C was very low in this study. Recombinant HIV strains being responsible for almost a quarter of cases among blood donors, a low risk population further depicts the increasing role of recombinants and dynamic nature of the HIV/AIDS pandemic HIV-1 subtype distribution was comparable with respect to gender. The study also demonstrates development of the capacity to genotype HIV-1 using the Real- Time PCR based MHAacd technique for the first time in Uganda.