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Unformatted text preview: An Overview of A n Overview of HIV and AIDS Author: Heather R Murphy What is HIV? W hat is HIV? HIV: human immunodeficiency virus HIV is the virus that causes AIDS AIDS: acquired immunodeficiency syndrome Part of group called Lentiviruses Origins O rigins Controversy regarding origin of HIV Other Lentiviruses collectively known as simian Other (monkey) viruses (SIV) (monkey) Generally accepted that HIV is descendent of Generally simian immunodeficiency virus (SIV) simian How could HIV have crossed species? Origins O rigins Earliest known instances of HIV: 1959: plasma sample taken from adult male in plasma Democratic Republic of Congo Democratic 1969: Tissue samples of African-American teenager Tissue in St. Louis in 1976: Tissue samples of Norwegian sailor Research shows HIV could have originated as Research early as 1930 early Timeline T imeline March 1981: 8 cases of KS reported in NY June 1981: 5 reported cases of PCP in LA December 1981: first cases of PCP in injection drug first users; first documented case of AIDS in UK users; June 1982: report suggests disease is sexually report transmitted transmitted May 1983: doctors in France isolate the virus Timeline T imeline April 1984: US Health and Human Services Secretary, April US Margaret Heckler, announces: Margaret “We hope to have a vaccine [against AIDS] ready for We testing in about two years…yet another terrible disease is about to yield to patience, persistence and outright genius.” outright Timeline T imeline January 1985: FDA licenses first HIV antibody test for FDA commercial production commercial End of 1985: AIDS has been reported in every region of the AIDS world world March 1987: FDA approves AZT; first antiretroviral drug for FDA AIDS treatment AIDS December 1, 1988: first annual World AIDS Day Timeline T imeline April 1990: Ryan White Care Ryan Act passed by Congress Act 1992: First successful use of First combination drug therapy combination December 1995: FDA FDA approves first protease inhibitors inhibitors June 1998: first human trial of first an AIDS vaccine an Structure S tructure Types, Groups and Subtypes T ypes, Groups and Subtypes 2 types of HIV: HIV-1 and HIV-2 HIV-2 less easily transmitted; period between HIV-2 initial infection and illness longer initial HIV-1: Predominant 2 groups, each with different subtypes Evidence suggests certain subtypes mostly Evidence associated with certain modes of transmission associated Transmission T ransmission Sexual Injection drug use Vertical transmission Blood products Health care setting Transmission Fluids T ransmission Fluids Blood Semen and pre-ejaculate Vaginal secretions Breast milk Threat of STDs T hreat of STDs Preventing STDs can be integral part of Preventing preventing HIV preventing Increase risk 2-5 fold Easier port of entry White blood cells HIV Testing H IV Testing 3 main types of HIV tests: HIV antibody test: shows if person has been shows infected infected P24 antigen test: primarily used to screen the blood primarily supply; sometimes used for individual testing supply; Viral load test: when HIV infection is known; shows when level of virus in blood level HIV Testing H IV Testing
Ways of testing: Blood Blood Saliva Testing Sites: Confidential Anonymous Rapid HIV test Home testing kit Stages of Infection S tages of Infection
The Basics: Mainly infects T helper lymphocytes T helper cells have CD4 protein on surface; used by helper HIV to enter the cell HIV Once inside cell, HIV takes over and replicates During process (a few days), cell dies New virus seeks new T helper cell to infect The immune system battles against to kill HIV and The HIV-infected cells and replace T helper cells HIV-infected Stages of Infection: Stage 1 S tages of Infection: Stage 1 Primary HIV Primary infection: infection: Lasts a few weeks; Lasts just after infection just Sometimes causes flulike symptoms Lots of HIV in Lots peripheral blood peripheral Stages of Infection: Stage 2 S tages of Infection: Stage 2 Clinically asymptomatic stage: Averages 10 years No symptoms Active in lymph nodes Stages of Infection: Stage 3 S tages of Infection: Stage 3 Symptomatic HIV Symptomatic infection: infection: Lymph nodes and Lymph tissues damaged tissues More pathogenic Can’t replace lost T Can’t helper cells fast enough enough Stages of Infection: Stage 4 S tages of Infection: Stage 4 Progression from Progression HIV to AIDS: HIV System damaged Illnesses more severe T helper cell count helper <200 AIDS diagnosis Treatment T reatment Antiretroviral Antiretroviral treatment treatment Combination Therapy HAART Groups of AntiHIV Drugs G roups of AntiHIV Drugs Nucleoside Reverse Nucleoside Transcriptase Inhibitors (NRTIs) (NRTIs) First HIV drug HIV needs reverse HIV transcriptase transcriptase NRTIs inhibit reverse NRTIs transcriptase transcriptase Groups of AntiHIV Drugs G roups of AntiHIV Drugs Non-Nucleoside Reverse Transcriptase Non-Nucleoside Inhibitors (NNRTIs) Inhibitors Slightly different from NRTIs Bind differently to reverse transcriptase Blocks duplication and spread of virus Groups of AntiHIV Drugs G roups of AntiHIV Drugs Protease Inhibitors Protease: digestive Protease: enzyme; breaks down protein protein HIV uses protease Slows process of immature Slows virus becoming infectious virus Slows production of virus Groups of AntiHIV Drugs G roups of AntiHIV Drugs Fusion or Entry Inhibitors Not yet approved In clinical trial stage Block proteins used to attach HIV to cells Slows down reproduction of virus Is injected Questions? Q uestions? ...
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