Charles Boucher MD. PhD. HIV Prevention 2.0

Transcription

1 Charles Boucher MD. PhD HIV Prevention 2.0

2 Prevention A variety of methods exists to prevent transmission of HIV Circumcision Condoms Post-exposure profylaxe (PEP) Treatment as prevention Pre-exposure profylaxe (PREP) etc

3 Stop the HIV pandemic Great enthiusiasm for decreasing the number of new HIV infections : Global goal UNAIDS: no new HIV infections through combining prevention approaches by 2030 A big challenge!

4 Costs Prevention is not cheap Limited resources Are policy makers prepared to invest? PrEP cost effective when used by MSM with a high risk for infection (Nichols et al Lancet Infect Dis 2016, J Acquir Imm Def Syndr 2014)

5 Cost effective Identify targeted strategies for different risk populations prevent a maxinum number of new infections at lowest costs

6 Sexual networks

7 Prevention HIV+, higher risk not diagnosed for a year What would have prevented most infections at lower costs? 1. PREP for all his partners? Low risk, high PREP costs 2. Frequent testing index case? eg every 6 montsh how many infections would have been prevented

8 Virological networks When Individual A infects individual B they have intially an identical virus Virological : genetic distance of 0 Over time through evolution in both hosts the viruses start to differentiate Analysis of sequences (resistance genotyping)

9 Fylogenetics: HIV tree Brenner et al. J Infect Dis 2007; 195: 951-9

10 Recent publications Proposed to use (real time) fylogenetic analysis to understand the epidemic and to recommend specific interventions

11 Challenges fylogenetics 1. Reconstruction transmission network? Resik et al. AIDS hum retrovir Dense sampling required

12 Sexual networks

13 Challenges fylogenitics 1. Reconstruction transmission network? Resik et al. AIDS hum retrovir Dense sampling required Netherlands: 23% 2012

14 Challenges fylogenitics 1. Reconstruction transmission network? Resik et al. AIDS hum retrovir Dense sampling required 3. Timing of samples (ideally all recent infections)

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16 1. Sources of hiv infection among msm and implication for prevention 2. Reconstruction transmission events network. 3. Dutch cohort msm, months infected 4. Identified the source for 617 recent infections ( ) by fylogenetic analysis of chronic infections

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18 Sources for transmission 1. 71% from undiagnosed men 2. 43% from men in first year of infection 3. 6% from men started therapy 4. 1% lost to follow up>18 months

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20 Estimation of preventable transmissions

21 Estimation of preventable transmissions

22 Conclusions 1. Lack of substantial reductions is not due to ineffective ART provision or inadequate retention 2. Rather due to frequent early transmission and continued low testing rate of men at risk of transmission 3. Increased annual testing and uptake of PREP in high risk MSM key role.

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24 Dynamics french acute infections patients with primary infection 3. Clinical, virological, geographical info 4. Objective: to characterise transmission networks

25 Dynamics french acute infections 1. 86% Caucasian men (71% MSM) (73% subtype B ) 209 CRF02-AG in clusterd: 156 dyads, 231 larger clusters 4. Genotype of reverse transcriptase

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28 Clusters french acute infections 1. More likely men, younger, white 2. Subtype CRF-AG 3. More recent 4. Three clusters 9, 14 and 42 infections, all white men and with geographical concentrations and during prolonged periods

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30 Intervention 1. Target all clustered individuals (223) before 2010 would have prevented 60 of 143 onward transmissions, 2. Targeting individuals in intermediate or high density clusters (79) would have prevented 33 onward new infections.

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32 Routine resistance genotyping for all new infections in British Columbia Analysed clusters, if >5 and followed over growth chracteristics of clusters were shared with public health officials

33 Ten most active clusters

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36 Ten most active clusters

37 Specific Interventions Initiate treatment in index case and keep him/her in care (clinical guidelines, treatment as prevention) Trace contacts (counsel partners), test them and treat them and keep them in care Search and destroy

38 Cluster 55 An additional case with drug resistance in 2014, subsequently 10 new cases, 8 with drug resistance. Enhanced public health follow up linkage to care, initiation of therapy, partner notification testing partners linkage to care and initiation of therapy

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40 Limitations & Challenges Ethical and legal considerations which differ per country The more and the earlier patients are diagnosed the easier it become to perform cluster analysis (screening strategies) Similarly the more effect can be obtained from partner identification, treatment and linkage to care

41 Conclusion. To achieve zero new infections in 2030 is a big challenge Contribution of HIV clinicians will be critical Close(r) collaboration between clinical and public health community.