Hiv: a Retrospective Overview Essay

2089 Words Apr 8th, 2012 9 Pages
Edwin Hill
Professor Skolnik
English 1280-05
Final Research Paper

HIV: Introspective Overview What is HIV? Figure 1 HIV 1 virus electron micrograph, (Goldsmith) Human immunodeficiency virus (HIV) is a retrovirus of the lentivirus genus. HIV attacks the immune system by invading and destroying certain white blood cells such as helper T cells (mainly CD4+ T cells), dendritic cells, and macrophages. The infection and destruction of the CD4+ T cells takes place through three methods: The direct viral killing of the infected cells, the apoptosis (programmed cell death) of infected cells, and the killing of infected CD4+ T cells by CD8 cytotoxic lymphocytes that recognize infected cells. Once the CD4+ T cells are
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These subtypes are lettered A, B, C, D, F, G, H, J and K. It is also noteworthy that on occasion two viruses of different subtypes meet in the cell of an infected person and, in a method similar to procreation, mix together their genetic material to create a new hybrid virus (sometimes called "viral sex"). The majority of these hybrid strains created by this process do not survive for long. The strains that do survive and infect more than one person are known as "circulating recombinant forms" or CRFs. Due to the fact that viral mutation and recombination shall continue, the future discovery of new HIV subtypes and CRFs is a certainty and the epidemic of current subtypes will persist (Noble, AVERT).
Earliest cases Through the study of the subtypes of some of the earliest known instances of infection, clues about the time at which HIV first appeared in humans, and its subsequent evolution, can be provided. A blood sample taken from an adult male living in what is now the Democratic Republic of the Congo in 1959, a lymph node sample taken in 1960 from an adult female (also from the Democratic Republic of the Congo), and tissue samples taken from both an American teenager who died in St. Louis in 1969 and from a Norwegian sailor who died around 1976 are four of the earliest found cases of HIV. An analysis of the blood sample from 1959, suggested that HIV was introduced into humans around the 1940s or the early 1950s. However, a study in

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