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HIV and TB Prevention and treatment. What multi- sectoral strategies will decrease the burden of infectious disease amongst the people of the Western Cape ?. A coherent strategy needs to be informed by the answers to the following questions….
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HIV and TB Prevention and treatment What multi-sectoral strategies will decrease the burden of infectious disease amongst the people of the Western Cape?
A coherent strategy needs to be informed by the answers to the following questions… • What is the scale of the HIV/TB epidemic in the Western Cape? • Where is it prevalent? • Why does it occur where it does? • What tools do we have to either prevent infection or to reduce disease severity, and how effective are they?
TB cases 2009 Central Karoo: 700 (1%) West Coast: 4,244 (8%) Cape Winelands: 9,892 (18%) Cape Town: 30,820 (55%) Eden: 7,204 (13%) Overberg: 3,059 (5%)
TB is the face of HIV • Being HIV-infected increases your risk of having TB by anywhere from 30 to 100-fold (depends on the stage of the HIV disease) • Proportionate to its population size, Western Cape is the province worst affected by TB TB is what is killing HIV-infected people
Recent HCT campaign Sites with > 1000 HIV+ tests – Red Sites with 400-1000 HIV+ tests - Yellow
Burden of HIV and TB ~270,000 HIV infected individuals ~50,000 diagnosed TB cases per annum Of HIV-infected people, 86% are in 14 sub-districts Of TB diagnoses, 76% are in the same 14 sub-districts These two diseases account for +/- a quarter of the years of life lost in the province
Why do certain areas carry a disproportionate burden of HIV disease? Because they harbour many of the risk factors associated with HIV1: The ‘deprivation cluster’ of: 1. Poverty 2. Overcrowding 3. Malnutrition 4. Migration Produce social vulnerability 1. Western Cape Burden of Disease report for major infectious diseases, 2007
Social vulnerability creates a high risk environment for HIV transmission By being strongly associated with the following risks1: • Not knowing one’s HIV status • Stigma and discrimination • Age mixing • Early sexual debut • Transactional sex • Partner turnover/concurrency • Alcohol misuse *disempowerment *compromised decision-making *economic necessity 1. Western Cape Burden of Disease report for major infectious diseases, 2007
Despite the socio-structural environment creating a context of high risk for HIV acquisition… the final mediator of HIV transmission is biological Viral transmission is a complex biological sequence of events that starts with ‘permanent’ viral attachment to host epithelial tissue Some people are more likely to transmit HIV and others are more vulnerable to acquire HIV • Sex & age • Viral load • Sexually transmitted infections • Lack of circumcision • Mother to child transmission
TB – another risky environment Risk 1 = Risk of being exposed to the organism (acquiring infection) • The ‘deprivation cluster’ of: impoverishment, poor nutrition, migration, overcrowded dwellings compounded byexisting high TB prevalence and incidence, poor education, ignorance of TB transmission mechanisms and of TB symptoms, poor adherence to treatment “85-90% of those people with normal immunity who inhale TB do not develop disease”
TB – another risky environment Risk 2 = Risk of infection progressing to disease TB infection can be longstanding and “reactivate” or can be recently acquired and progressive “50-90% of South Africans are likely to be latently infected with TB” “by far the most powerful risk identified (for infection progressing to disease) is concurrent HIV infection”
Interventions • We’re not only trying to prevent new HIV and new TB infections • We also have a large population of people who are already HIV-infected, and in whom we are trying to prevent premature death
HIV prevention can and should be implemented at different levels Biomedical – attempt to block infection or reduce infectiousness Behavioural- attempt to motivate behavioural change within individuals or communities Structural- seek to change the context that contributes to vulnerability or risk
Biomedical interventions need to be placed into the high risk environments- at scale (and socio-structural barriers to their consistent and correct use need to be overcome)
TB interventions • Reduce the probability of someone inhaling the mycobacterium Tuberculosis • Tackle the ‘deprivation cluster’ – overcrowding etc • Reduce prevalent and incident TB (case-finding – ART work-up, door-to-door community drives etc..) • Reduce/prevent drug-resistant TB • Reduce infectiousness of those with TB (case-treatment and case-holding) • Environmental infection control (applying not only to health facilities but all areas where people congregate – transport, work, church, bars etc)
TB interventions • Reduce the probability of inhaled (or latent) tuberculosis progressing to active disease • Early identification of high risk cases (HIV testing) and intensive education of disease symptoms • Regular routine monitoring of high risk cases • ‘Bolster immunity’: ART where indicated • IPT where appropriate
A word on Mother-to-child transmission Pre-conception MTCT – effective contraception is a powerful tool to prevent transmission of HIV from mother to child. 100% effective Antiretroviral drugs (dual and triple therapy) reduce viral load, reduce probability of transmission. The earlier started, the better Pre-partum Antriretroviral drugs and reducing birth trauma (C/S) Intra-partum Post-partum Antiretroviral drugs for mother and child. Breastfeeding choices and drug cover to the child for the duration of breastfeeding
We know the following about HIV infections in the Western Cape… • In the absence of a ‘game-changing’ intervention, the Western Cape will see approximately ~14,000 HIV infections in 2012 (~1,200 of which will be from mother to child) • We can identify the communities in which the~14,000 transmission events will occur • We have the biomedical tools and knowledge to theoretically stop almost every one of those transmission events… But we’re missing apiece of the puzzle… And it revolves around generating large scale demand for, and consistent uptake of, proven biomedical interventions by high risk communities
It’s not clear how we are going to solve this vexed problem, but let’s try and picture the type of societal and community norms that would be required to reduce HIV and TB transmission…
What’s the “ideal world” scenario? • Structural: to do away with the ‘deprivation cluster’ • Societal/behavioural: An environment in which everybody… • Is informed of the consequences of HIV infection, knows their HIV status, checks it regularly and no stigma is attached to doing so • Uses barrier protection consistently, and especially with casual sex; has immediate access to condoms whenever they want them and their use of condoms is positively re-enforced by their partner, their peer group and their community • Delays their sexual debut and avoids having multiple sexual partners • Men present for circumcision routinely • Women use contraception consistently and space their pregnancies well • HIV-infected pregnant women know their HIV status and present very early in their pregnancy for treatment
What’s the “ideal world” scenario? • Societal/behavioural: An environment in which every HIV-infected person… • Knows that they are at unusually high risk of TB • Knows how to recognise TB, knows simple household and community infection control measures, knows the benefits of TB preventative therapy, knows what to do and where to go if they think they have TB • Who is HIV-infected is able to keep themselves well by routinely undergoing monitoring (for TB, cervical cancer etc) and being rapidly responsive to new symptoms
What’s the “ideal world” scenario? • Biomedical An environment in which everybody… • Has simple and rapid access to HIV and TB testing • Has easy access to required medication • Adheres to their prescribed treatment because they understand it benefits them, are aware of the consequences of not doing so, and are supported in doing so by their peers and their community
UNAIDS suggested high level strategies… • “Highly active HIV prevention inevitablymust be combination prevention” • “Nothing should be more important than a focus on young people” • “investments should focus on promoting normative and social change to reduce multiple and concurrent partnerships, and to greatly increase availability of safe and affordable male circumcisionservices” • “condoms (unlike contraception) have to be available immediately and thus a continuous source of supply is needed” • “The aggregate effect of radical and sustained behavioural changes in a sufficient number of individuals potentially at risk is needed for successful reductions in HIV transmission” “ Understand but don’t overcomplicate. Broad rapid brushstrokes are sufficient for action”