Human Immunodeficiency Virus HIV Mr. Mohamed M. Kashbor The University of Huddersfield The School of Applied science Advanced stage The definition of HIV As it can be seen from (fig, 2) MSM has a high percentage of HIV infection during the period of 1981 and 2011, which is recoded 82% between the years of 1981 and 1983. then, the infection of MSM has been reduced to be 48% in the year of 2011. While other categories were less than 40% over that time as it appears in the (fig, 2). Moreover, other causes of HIV infection, which are Perinatal, mother to infant Blood products, Percutaneous injury and mucosal contamination in healthcare workers can be found [6]. In the final phase of severe cellular immunosuppression, the cell-mediated immune system collapses and a variety of infections and tumours (i.e., AIDS) that are normally at bay develop [5]. HIV is a virus that attacks the immune system and weakens the ability of the body to fight infections and disease. There are two types of HIV, which are HIV-1 and HIV-2 [1]. They have the same modes of transmission and are associated with the same opportunistic infections, but HIV-2 appears to progress more slowly [2]. The clinical aspects of HIV Figure (4) shows Clinical presentation of the primary forms of oral candidosis [7]. The therapeutic avenues of HIV Modern therapy is directed along three paths: The anti-HIV drugs include reverse transcriptase inhibitors (RTI) such as azidothymidine (AZT) and the more recent protease inhibitors [5]. Prophylactic therapy usually includes the effective anti-Pneumocystis agent cotrimoxazole. It also has an anti-Toxoplasma effect [5]. The treatment of specific opportunistic diseases involves a wide range of potent drugs with the expected occurrence of multi-organ toxicities [5]. Figure (1) shows the structure of the HIV [3]. The modes of HIV Infection Figure (3) illustrates the main symptoms of HIV infection [3]. The first desecration of HIV-infected was in 1981by New England Journal of Medicine, which is noted that four previously healthy homosexual men developed pneumonia from an infection caused by Pneumocystis carinii. Furthermore, by 1995 other reports were described hundreds of cases involving homosexual men, intra-venous drug users and other receiving blood products for medical therapy [4] & [5]. As it can be seen from (fig, 3) there are several negative impacts on the infected body that can be appeared after the infection of HIV. These sings are divided into three induvial stages: In this stage and after the infection HIV will goes throughout the lymphoid system with a transient drop in blood CD4+ T-cell counts. Also, cytotoxic lymphocytes (CTL) will be developed [5]. At this stage HIV infection is destroying T-cells a rate (2 x 109/day) faster than they can be replenished. Whilst viraemia is low or undetectable, virus is present productively and latently in the lymphoid system [5]. Primary stage References J. Melnick and N. Khan, Human immunodeficiency virus, Karger, Basel, 1990. M. Oldstone, Viruses, plagues, and history, Oxford University Press, New York, 1998. M. Farabee, On-Line Biology Book, 2007. M. Lederman, Thromb Haemost, 2010, 104, 911-914. S. LUCAS, med, 1999, 7, 9-16. Public Health Agency of Canada, 2014. D. Williams and M. Lewis, Journal of Oral Microbiology, 2011, 3. Mild stage Figure (2) shows Distribution of estimated new HIV infections in Canada over time [7].