New infections and HIV-1 subtypes among febrile persons and blood donors in Oyo State, Nigeria

Abstract

Purpose: There were approximately 37.9 million persons infected with HIV in 2018 globally, resulting in 770,000 deaths annually. Over 50% of this infection and deaths occur in sub-Saharan Africa, with countries like Nigeria being seriously affected. Nigeria has one of the highest rates of new infections globally. To control HIV infection in Nigeria, there is a need to continually screen high-risk groups for early HIV infection and subtypes using very sensitive methods. In this study, new HIV-1 infection and circulating HIV-1 subtypes among febrile persons and blood donors were determined. Performance characteristics of three commercial EIA kits were also evaluated.

Methods: In total, 1028 participants were recruited for the study. New HIV-1 infection and subtypes were determined using enzyme immunoassays and molecular techniques, respectively. Sensitivity, specificity, predictive values, and agreements were compared among the EIA kits using PCR-confirmed HIV-positive and negative samples.

Results: The overall prevalence of HIV infection in this study was 5.35%. The rate of new HIV infection was significantly different (p < .03674) among 1028 febrile persons (Ibadan: 2.22%; Saki: 1.36%) and blood donors (5.07%) studied. Three subtypes, CRF02_AG, A, and G, were found among those with new HIV infection. Whereas the commercial ELISA kits had very high specificities (94.12%, 100%, and 100%) for HIV-1 detection, Alere Determine HIV-1 antibody rapid kit had the lowest sensitivity score (50%).

Conclusion: Genetic diversity of HIV-1 strains among infected individuals in Oyo State, Nigeria, is still relatively high. This high level of diversity of HIV-1 strains may impact the reliability of diagnosis of the virus in Nigeria and other African countries where many of the virus strains co-circulate.

Keywords: CRF02_AG; ELISA; HIV-1 rapid kits; HIV-1 subtypes; High-risk groups.

FIGURE 1

Diagram showing the testing flow chart. Values are shown in numbers only. A total of 1028 persons were recruited for the study after obtaining informed consent. In total, 890 were febrile persons, whereas 138 were voluntary blood donors. All (n = 1028) samples were tested on Genscreen ULTRA HIV-1 Ag/Ab and AiD anti-HIV-1/2 ELISA kits. A subset of the samples (n = 671) was tested on Alere Determine HIV-1/2 Rapid Antibody. All HIV-positive samples (n = 56) were further confirmed on PCR

FIGURE 2

Summary of subtypes isolated from individuals with new HIV-1 infection. Values are shown in percentages only. (A) A pie chart showing the distribution of subtypes isolated from voluntary blood donors. The total number of individuals in this group is 8. One sample was not sequenced. Also, 4, 2, and 1 samples were subtyped as CRF-02 AG, G, and A, respectively. (B) A pie chart showing the distribution of subtypes isolated from febrile persons. The total number of individuals in this group is 6. Also, 4, 1, and 1 samples were subtyped as A, CRF-02 AG, and G, respectively

FIGURE 3

Phylogenetic tree of the P17/P24 regions of the GAG gene of HIV-1. Reference subtypes are indicated with Ref. before their accession numbers. Other sequences are indicated with their accession numbers and country of isolation. Subtypes obtained from samples in this study are indicated with their accession numbers only. Subtypes A, G, and CRF02_AG were identified with green diamond, blue circle, and pink square symbols, respectively. Multiple sequence alignment and phylogenetic tree were constructed using MAFFTS and Maximum Parsimony algorithm in MEGA 6 software. Statistical significance of the tree topology was tested by 1000 bootstrap replication