HIV 101 Dr Sindisiwe van Zyl sindi@drsindi.co.za Saturday 25 August 2018 Pretoria

Introduction

MAP OF THE WORLD © Copyright SASI Group (University of Sheffield) and Mark Newman (University of Michigan).

Worldwide HIV prevalence in adults aged 15 – 49 © Copyright SASI Group (University of Sheffield) and Mark Newman (University of Michigan). Map from worldwide mapper showing country size according to HIV prevalence

WHAT IS HIV? retrovirus and a lentivirus – slow progress The HUMAN IMMUNODEFICIENCY VIRUS (HIV) retrovirus and a lentivirus – slow progress uses the body’s own cells to make copies of itself attacks the body’s immune system causes AIDS – Acquired Immune Deficiency Syndrome

BACK TO BASICS CD4 cells – most important cells in the body “army” HIV – targets CD4 cells, hijacks them and starts making copies of itself VIRAL LOAD – the number of HIV copies in your body ART antiretroviral therapy – combination of 3 or more ARVs taken to suppress the virus’ ability to make copies of itself

What else do we know about HIV? 2 types of HIV HIV - 1 – global distribution, mutates easily many subtypes of HIV - 1: A - K southern Africa subtype C dominates HIV - 2 – isolated to West Africa slower disease progression 5 subtypes

TRANSMISSION OF HIV unprotected sexual intercourse with an infected person from mother to child – pregnancy, labour and delivery, breastfeeding occupational exposure infected blood products

NOT transmitted by… Casual contact – handshakes Hugging Sharing cups and utensils Coughing or sneezing Crying Sweating Kissing

Risk factors for transmission Biological risk factors presence of STIs women more vulnerable physiologically semen is deposited into vagina, stays there for days whilst males “dip in & dip out” area of mucous membrane exposed during sex much larger viral load in source partner (genetics – co-receptor deletion; < 1% of population) Not all penetrative sexual contact with an infected partner leads to infection SERODISCORDANT COUPLES

Structure of HIV

Target cells of HIV “ the enemy” HIV targets specific cells of the immune system “army” cells with CD4 receptors happen to be VERY important members of the defence force

Life cycle of HIV Binding+ fusion Releases contents Makes RNA into DNA Inserts its own DNA into human DNA Takes over the cell and makes new viruses

many millions of viruses are made daily – viral load CD4 cells are destroyed in the process immune system can no longer function normally; inflammatory process

4 Stages of HIV infection Primary and acute HIV infection ‘window period’ followed by seroconversion: production of antibodies asymptomatic phase symptomatic disease AIDS

Primary and acute HIV infection initially asymptomatic then 6 – 12 weeks after infection non-specific viral symptoms HIGH viral load a drop in CD4 count “window period” seroconversion

Asymptomatic phase no symptoms for years but do not be fooled the war is raging on… CD4 cells putting up a fight but immune system is suffering

Symptomatic phase immune system ‘tired’ mild symptoms initially but gradually worsen opportunistic infections

AIDS immune system can no longer function normally without ART death follows

Anti-retroviral Therapy ART Reverse transcriptase inhibitors X Fusion inhibitors X X Integrase inhibitors X Protease inhibitors Maturation inhibitors X

Treatment works!

Three-in-one combination

New kid on the block

HIV affects eveybody Nobody is immune – NO assumptions! (Almost) everyone is sexually active Test BEFORE embarking on a sexual relationship Keep testing – every 6 – 12 months

Know your HIV status Every individual must know their status Cannot rely on your partner to test on your behalf “proxy testing” It is better to know earlier rather than later

Condoms work If used correctly and consistently Intermittent use is the same as no use Male condom and female condom Non-latex condoms are available - expensive

PEP Post Exposure Prophylaxis

PEP Post Exposure Prophylaxis Pre-condition: YOU must be HIV negative Must be taken within 72 hours of exposure Must be taken for 28 days Repeat HIV test after the course and after 12 weeks

PrEP Pre Exposure Prophylaxis

PrEP Pre Exposure Prophylaxis Part of “Combination Prevention” strategy Trials have proven efficacy: >90% effective Commit to three – four monthly check-ups Lead-in time: tablet must be taken DAILY 7 days with recipient anal sex 20 days with vaginal sex

Undetectable equals Untransmittable

Resources www.unaids.org www.thebody.com sindi@drsindi.co.za