louisa degenhardt 1, bradley mathers 1, peter vickerman 2, tim rhodes 3, carl latkin 4 and matt...
TRANSCRIPT
Prevention of HIV infection for people who inject drugs:
Why individual, structural and combination approaches are
neededLouisa Degenhardt1, Bradley Mathers1, Peter Vickerman2,
Tim Rhodes3, Carl Latkin4and Matt Hickman5
1. National Drug and Alcohol Research Centre, University of NSW, Australia2. London School of Hygiene and Tropical Medicine, UK3. Centre for Research on Drugs and Health Behaviour, LSHTM, UK4. Johns Hopkins Bloomberg School of Public Health, USA
5. University of Bristol, UK
Interventions for preventionmechanism of effect
Preventing HIV transmission among people who inject drugs: multiple mechanisms
Prevention of injecting related transmission: reduce injecting frequency
reduce unsafe injecting events
reduce HIV infectivity
Sexual transmission:reduce unsafe sexual events
reduce HIV infectivity
Interventions for preventionevidence of impact
Inject. frequency
Injecting risks
Sex risks HIV infectivity
HIV incidence
HIV testing -- ↓ ↓ -- --Individual interventions for HIV risk ↓ ↓ ↓ -- --Network/peer interventions for HIV risk ↓ ↓ ↓ -- --Needle syringe programs (NSP) ↓ -- -- ↓Condom provision -- -- ↓ -- ↓Opioid substitution therapy (OST) ↓ ↓ -- ↓Naltrexone – Oral -- -- --Naltrexone – Implant ↓ ↓ -- -- --Pharmacotherapy for stimulant dependence -- --CBT for stimulant dependence ↓ -- -- -- --STI treatment -- -- -- -- ↓Antiretroviral treatment (ART) -- -- -- ↓ ↓Safe injecting centres (SICs) ↓ -- -- --Compulsory detention of drug users -- ↑ ↑ -- --
Modelling impactvarying coverage and combinations
Modelling different levels of intervention coverage and combination
• Extended an existing deterministic model developed by Vickerman et al
• Epidemiological parameters and effect sizes used were based on observed data:• Injecting HIV epidemics• Frequency of risk behaviours• Impact of OST, NSP and ART on HIV transmission• Service coverage levels
Effects of recruitment rates and intervention combinations on HIV incidence after 5 years
OST and NSP only, 50% recruitment annually: 9-37% reduction in HIV incidence
ART onlyCD4 <200
OST + NSPonly
ART only,CD4 <350
OST + NSP + ART
Effects of recruitment rates and intervention combinations on HIV incidence after 5 years
ART onlyCD4 <200
OST + NSPonly
ART only,CD4 <350
OST + NSP + ART
ART to CD4<200 only, 50% recruitment annually: 5-17% reduction in HIV incidence
Effects of recruitment rates and intervention combinations on HIV incidence after 5 years
ART onlyCD4 <200
OST + NSPonly
ART only,CD4 <350
OST + NSP + ART
ART to CD4<350 only, 50% recruitment annually: 9-34% reduction in HIV incidence
Effects of recruitment rates and intervention combinations on HIV incidence after 5 years
ART onlyCD4 <200
OST + NSPonly
ART only,CD4 <350
OST + NSP + ART
OST+NSP+ART<350, 50% recruitment annually: 18-63% reduction in HIV incidence
Current coverageOST, NSP and ART
© Reference Group to the United Nations on HIV and Injecting Drug Use 2010
Global estimate of the number of IDUs:15.9million (11.0-21.2 million)
Reports of injecting drug use in 151 countries
Needles-syringes distributed, per IDU, per year
less than 100
100 – 200
greater than 200 NSP present but program data not available
No IDU reportedNo NSP
Needles-syringes distributed, per IDU, per year
Globally, overall, only 22 needles-syringes (range 12-42) are distributed per IDU per year
Opioid substitution therapy (OST)
Present in 75 countries Absent in 76 countries where injecting occurs
Number of OST recipients for every 100 IDUs
Globally, overall, only 8 people on OST (range 6-12) for every 100 IDUs
Number of IDUs on ART per 100 HIV+ IDUs
less than 25
25 – 75
greater than 75 IDU present but ART program data not available
No IDU reportedNo OST
Number of IDUs on ART per 100 HIV+ IDUs
Globally, overall, only 4 IDUs on ART (range 2-18) for every 100 HIV+ IDUs
Improving coveragesocial and structural interventions
Policy and environmental factors influence accessibility, coverage and quality of services
It necessary to address these structural barriers
For example: • Creating safer injecting environments; • Reforming laws prohibiting treatments; • Reducing the harms of policing
Improving coverage and impact of prevention interventions
In summary:• High coverage of ART and OST and NSP can reduce HIV
incidence in IDUs by more than 50%Short-term, small-scale interventions unlikely to impact
• Current coverage is vastly inadequate few countries have high coverage of any intervention -
very few have high coverage of all three
• Structural factors limiting impact and needed when environmental factors limit scale-up
•We know enough to act now But the evidence base must continue to improve so we can continue to improve the response: surveillance, monitoring and evaluation, efficacy and (cost) effectiveness
Acknowledgments
Chiara Bucello, Mary Kumvaj, Erol Digiusto, Tomas Zabransky, Mauro Guarinieri, Mukta Sharma, Maria Prins,Judy Auerbach, Francisco Bastos, and Don Des Jarlais
The Lancet Special Series gurus: Chris Beyrer, Steffanie Strathdee, Adeeba Kamarulzaman, Kasia Malinowska-Sempruch
The Lancet Editors: Pamela Das and Richard Horton