HIV-1 Subtypes and Recombinants in Northern Tanzania: Distribution of Viral Quasispecies

Abstract

This study analyzed the distribution and prevalence of HIV-1 subtypes, multiplicity of HIV-1 infection, and frequency of inter-subtype recombination among HIV-1-infected female bar and hotel workers in Moshi, Kilimanjaro Region, Tanzania, from 2004 to 2007. The HIV-1 viral sequences spanning the V1-C5 region of HIV-1 env gp120 were analyzed from 50 subjects by single genome amplification and sequencing (SGA/S) technique. A total of 1740 sequences were amplified and sequenced from the HIV-1 proviral DNA template. The median env sequences analyzed per subject per two time points was 38 (IQR 28–50) over one year of HIV infection. In a subset of 14 subjects, a total of 239 sequences were obtained from HIV-1 RNA template at the baseline visit. The most prevalent HIV-1 subtypes were A1 (56%) and C (30%), while HIV-1 subtype D and inter-subtype recombinant viruses were found in 6% and 8% of subjects respectively. Transmission of multiple HIV-1 variants was evident in 27% of the subjects infected with pure HIV-1 subtypes A1, C, or D. The HIV-1 inter-subtype recombinants were found in 8% including HIV-1 C/A, D/A, and complex mosaic recombinants. Multiple viral variants were found in two subjects infected with inter-subtype recombinants. One subject harbored quasispecies of both pure HIV-1 A1 and C/A recombinant. The other subject was infected with two complex mosaic inter-subtype recombinant variants belonging to subtype D. HIV-1 multiple infections and ongoing recombination contribute significantly to the genetic diversity of circulating HIV-1 in Tanzania and have important implications for vaccine design and the development of therapeutic strategies.

HIV-1 Diversity in Tanzania and its Implication toward Development of Effective Vaccines: A Review Article

“…The current work which was done in Mwanza Tanzania showed low prevalent of recombinant comparing to the previous studies [33]. This study pointed out the predominant HIV-1 subtypes was A and C which is similar to the previous work from Kilimanjaro by Ireen and Nyombi [11,23]. When we combine all information from these studies in different part of Tanzania we are getting groundwork for the future HIV-1 vaccine in the region.…”

“…Of more interest viruses from different lineages within group M are able to recombine during infection and form recombinant viruses [23,24]. Currently more 60 circulating recombinant forms (CRFs) and a large number of unique recombinant forms (URFs) have been described [25], providing evidence for ongoing evolution of HIV-1 in the global epidemic [11]. Furthermore, individuals infected with multiple HIV-1is well as individuals infected with multiple strains of the same HIV-1 subtype have been reported [26].…”

“…Furthermore, HIV-1multiple variants were reported in almost quarter of a high-risk population of female bar and hotel workers with acute HIV-1 infection in the Mbeya region of Tanzania. It is possible that female commercial sex workers and their male clients, as well as female bar and hotel workers, contribute substantially to the rapid expansion of the HIV-1 epidemic in developing countries like Tanzania [11]. These populations may play an important role in evolution facilitating multiple infections and recombination events [13].…”

“…With high diversity of virus in West and Central Africa, very few strain have spread with only four principle subtype and at least two Circulating recombinant Forms (CRFs) been responsible to more than 90% of global epidemic [10]. More than 50% of global infection is due HIV-1 Subtype C, where about 15% Subtype A, 12% Subtype B, 5% Subtype G, 2% Subtype D and about 20% being recombinant forms [10,11]. The diversity of Subtypes is very distinctive in such a way that strains belonging to the same subtypes like HIV-1 C from Kenya and HIV-1 from Tanzania can differ by up 20% in their env gene while the different between HIV-1 A and HIV-1 C env differ by 35% [12].…”

“…The diversity of Subtypes is very distinctive in such a way that strains belonging to the same subtypes like HIV-1 C from Kenya and HIV-1 from Tanzania can differ by up 20% in their env gene while the different between HIV-1 A and HIV-1 C env differ by 35% [12]. Basing on the different presented and HIV virus is continuously evolving with the possibility of super-infection or co-infection means there is increasing genetic distance between strains and formation of intra-subtypes recombinant forms [11] (Table 1). Table 1: The degree of HIV-1 Subtypes and inter-subtypes diversity and its diversity in Africa is summarised [8].…”