The public health significance of HIV-1 subtypes

Genetic Diversity and the Human Immunodeficiency Virus Type-1: Implications and Impact

“…The extensive genetic variation which characterizes HIV-1 is an important feature of the HIV/AIDS epidemic (Robertson et al, 2000). The genetic variability of HIV-1 is generated by the lack of proof reading ability of the reverse transcriptase, the rapid turn-over of HIV-1 in vivo, host selective immune pressures and recombination events during viral replication Ho, 1995;Michael, 1995;Tatt, 2001). This has several public health implications although the biological significance is not known (Loussert-Ajaka, 1998;Tatt, 2001).…”

“…The genetic variability of HIV-1 is generated by the lack of proof reading ability of the reverse transcriptase, the rapid turn-over of HIV-1 in vivo, host selective immune pressures and recombination events during viral replication Ho, 1995;Michael, 1995;Tatt, 2001). This has several public health implications although the biological significance is not known (Loussert-Ajaka, 1998;Tatt, 2001). The HIV-1 subtypes vary in the geographical distribution of the virus Tatt, 2001).…”

“…This has several public health implications although the biological significance is not known (Loussert-Ajaka, 1998;Tatt, 2001). The HIV-1 subtypes vary in the geographical distribution of the virus Tatt, 2001). The differences in HIV-1 subtypes and geographic diversity impact the development of efficacious vaccines, diagnostic testing and antiviral therapy (Borrow, 1997;Loussert-Ajaka, 1998;Piot, 2001).…”

“…Sequencing and phylogenetic analysis are still the most accurate approach for characterizing viral genomes in identifying new subtypes, sub-subtypes, recombinant, complex and unique forms of HIV-1 and are well documented Loussert-Ajaka, 1998;Tatt, 2001). These methodologies have been important tools in determining sequence relatedness, mutational changes relating to viral ancestry, the relative time of viral introduction, mutations associated with antiretroviral drug resistance, viral transmission patterns and other epidemiological information (Leitner et al, 1998).…”

“…The definitive method of subtyping HIV-1 is the genetic sequencing of the envelope (env), group antigen (gag) or polymerase (pol) The main advantages of this method are that it allows the determination by phylogenetic analysis of the relatedness among HIV sequences, the study of the evolution of HIV quasispecies in different hosts linked to a common source of infection, and the study of virus transmission patterns among different risk groups (Diaz, 1997;Holmes, 1995;Leitner, 1999). However genetic sequencing is expensive, time consuming and requires highly qualified personnel (Hu, 2005;Loussert-Ajaka, 1998;Tatt, 2001). In addition phylogenetic methods have been widely used to investigate alleged person to person transmission of the virus, for example, from health care professionals to their patients (Holmes, 1993;Ou, 1992).…”