title: Human immunodeficiency virus type-2-A milder, kinder virus: an update.
abstract: Human immunodeficiency virus type-2 (HIV-2) belongs to the family retroviridae which is phylogenetically clusters with SIV SM from sooty mangabeys. This virus is morphologically similar to human immunodeficiency virus type-1 (HIV-1) but has got only a 40% homology at the nucleotide level. There is a distinct geographical distribution of HIV-2 unlike HIV-1. There are currently eight subtypes/groups identified with subtype/group A responsible for the majority of infections. HIV-2 shows a considerable difference in the course of the disease. Clinical, haematological and immunological evaluation of individuals infected with HIV-2 has shown the virus to be less pathogenic than HIV-1 although the exact mechanism underlying this difference is not well defined. Similar to HIV-1, the HIV-2 isolates also showed distinct replicative and cytopathic characteristics. The transmission rate for HIV-2 compared to HIV-1 is very low both by heterosexual route and mother to child transmission. The clinical signs and symptoms of immunodeficiency associated with HIV-2 are similar to the ones seen among the HIV-1-infected individuals and they can also progress to AIDS. It is naturally resistant to NNRTI and hence the diagnosis become important as it affects the treatment strategy. Similar to HIV-1, HIV-2 strains of infected individuals also show mutations that can cause drug resistance. The current evidence suggests that there is no protective effective for HIV-2 against HIV-1.
authors.affiliation: Department of Clinical Virology, Christian Medical College, Vellore - 632 055, India. rajeshkannangai@hotmail.com
authors.forename: R
authors.initials: R
authors.lastname: Kannangai
authors.forename: S
authors.initials: S
authors.lastname: David
authors.forename: G
authors.initials: G
authors.lastname: Sridharan
mesh_terms: D019380:Anti-HIV Agents / Q000494:pharmacology / Q000627:therapeutic use; D018562:Disease Transmission, Infectious; D024882:Drug Resistance, Viral; D015658:HIV Infections / Q000453:epidemiology / Q000473:pathology* / Q000635:transmission / Q000821:virology*; D015498:HIV-2 / Q000145:classification / Q000235:genetics / Q000302:isolation & purification* / Q000472:pathogenicity*; D006801:Humans; D058974:Phylogeography
chemical_list: D019380:Anti-HIV Agents