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HIV & AIDS. Dr Sat Das Associate Professor Lead Consultant Physician, HIV / GUM University Hospitals Coventry & Warwickshire. Topics. What is AIDS and what is HIV Epidemiology of HIV Natural course of HIV Transmission of HIV Treatment of HIV: What is HAART and how it works
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HIV & AIDS Dr Sat Das Associate Professor Lead Consultant Physician, HIV / GUM University Hospitals Coventry & Warwickshire
Topics • What is AIDS and what is HIV • Epidemiology of HIV • Natural course of HIV • Transmission of HIV • Treatment of HIV: What is HAART and how it works • Post-Exposure Prophylaxis (PEP) • Pregnancy and HIV • Cases: Change in disease spectrum
AIDS and HIV What is AIDS? • Acquired Immuno Deficiency Syndrome • acquired as opposed to congenital; Caused by HIV: • Human Immunodeficiency Virus • a retrovirus with an ssRNA genome.
Background • First recognized cases of AIDS occurred in 1981 in San Francisco • Reports of Pneumocystis carinii pneumonia and Kaposi’s sarcoma in young homosexual men • Virus known to cause AIDS discovered in 1983 • First cases of AIDS appearing in UK in 1983 • Antibody test developed in 1984
Global HIV • 33 million adults and 2 million children living with HIV at the end of 2008 • 2.7 million new HIV infections in 2007 • Two million HIV-related deaths world wide http://www.who.int/hiv/pub/en/
HIV in the United Kingdom: 2008 report (HPA) • The estimated number of people living with HIV in the UK has increased from just over 16,000 in 1990 to over 83,000 in 2008 • 7298 new diagnoses in 2009 • More than a quarter (28 per cent) unaware of their infection
Transmission of HIV • Sexual (anal > vaginal > oral) • Increased in presence of STIs • Vertical > 30% (reduced to <1% with intervention) • Intravenous drug use • Transfusion and blood products Principal transmission routes in the UK: • Heterosexual sex (50%) • Homosexual sex (39%) • Drug injection (3%)
The risk of HIV transmission following an exposure from a known HIV positive individual
HIV replication • The “target cells” for virus replication are • CD4 T cells; • macrophages; • some CNS cells (microglia, these are brain macrophages) • Infected CD4 T cells are the main source of HIV in an infected individual.
virus released, infects more cells virus replicates, cell dies Uninfected cell activation e.g. by antigen or cytokines Non-proliferating cells latently infected: virus reservoir
Natural Course of HIV Infection CD-4 count /ml HIV RNA / ml 1000000 Relative latency 1000 HIV RNA CD-4 cells 500000 500 350 200 0 0 1 2 3 4 5 6 1 2 3 4 5 6 7 8 9 10 11 12 13 Months Years after HIV infection
Anti-retroviral drugs • These target replicating virus • Different drugs are used in combination in the hope of beating resistance mechanisms • Therapy is life-long and expensive
What is HAART? • Highly Active Anti-Retroviral Therapy (HAART) • Combination Anti-Rretroviral Therapy (CART) What to start with? • 2 NRTIs and 1 NNRTI: recommended • 2 NRTIs and 1 PI: consider • Other combinations
HIV Interventions Based onCD 4 Count CD 4 Count Intervention <350 Consider HAART <200 PCP prophylaxis
Post-Exposure Prophylaxis (PEP) • PEP consists of triple therapy • Not licensed • Offered only where the risk is high • Should be offered within 72 hours • Best result within 1 hour of the contact
Prescribing Recommendations • AZT inclusion • 2 NRTIs (AZT&3TC) + • PI (Lopinavir/r) • Starter packs of 3-5 days • Duration of treatment= 28 days
From March 1986 to 2007 • 8155 pregnancies • 6499 deliveries • 1583 (18%) children infected from mother
Factors affecting mother to child transmission • In utero • During delivery • After birth – breast feeding
Transmission Mother to child transmission without intervention • 15-20% in non breast feeding • 30-40% in breast feeding
Interventions • Antiretroviral therapy • Delivery • Formula feeding • Treatment for neonate Risk of transmission <1%
Pre conception and fertility management Uninfected male – self insemination Uninfected female – sperm washing
HIV-infected individuals are now living longer 25000 100000 20000 80000 15000 60000 AIDS cases and deaths Living with HIV 10000 40000 5000 20000 0 0 1984 1986 1988 1990 1992 1994 1996 1998 2000 2002 2004 Year AIDS Deaths Living with HIV EUROHIV. HIV/AIDS Surveillance in Europe: End-year report 2004, No. 71available at http://www.eurohiv.org/reports/index_reports_eng.htm (accessed April 2006)
Non-AIDS conditions: Drug related toxicities • Mitochondrial disorder • Metabolic • Bone disease • Renal disease • Fat redistribution • Liver disease • CNS involvement
Take-home points • HIV/AIDS is a treatable condition • Outlook for developing countries is still bleak • Change in disease spectrum • Rubber technology plays an important role
Recommended information sources • ABC of AIDS, BMJ Books • www.BHIVA.com • www.aidsmap.com • www.medscape.com