Transcript view the slides

Can we prevent infection after an
exposure? The world of post-exposure
prophylaxis (PEP)
James Wilton
Project Coordinator
Biomedical Science of HIV Prevention
[email protected]
1
2
HIV/AIDS in Canada
• Number of people living with HIV
• 57,000 in 2005
• 65,000 in 2008
• 2,200 to 4,200 infected in 2005
• 2,300 to 4,300 infected in 2008
•
•
•
•
MSM (44%)
People who use injection drugs (17%)
Women (26%)
Aboriginal (12.5%)
Source: Public Health Agency of Canada
2
3
Improving HIV prevention
1.
Do better with the strategies that we already have
2.
Develop new biomedical technologies to prevent HIV
3.
Adopt a more comprehensive approach to HIV/AIDS
prevention
What is post-exposure prophylaxis (PEP)?
• Post
 After
• Exposure
 When a fluid containing HIV comes into contact with
mucous membranes or non-intact skin
• Prophylaxis
 An action taken to prevent infection or disease
What is PEP to prevent HIV infection?
• The use of a combination of antiretrovirals by HIVnegative individuals for a short period of time after a
suspected or known exposure to HIV
• Must be started as soon as possible but within 4872 hours after the exposure
• Must be taken everyday for 28 days
• Must avoid additional exposures while taking PEP
• Types of exposures
• Occupational
• Non-occupational
5
Occupational vs. non-occupational exposures
Occupational
• Work-related exposures to HIV
• Needle-stick injuries
• Sharp objects
• “Standard of care”
Non-occupational (nPEP)
• Exposures outside of the workplace
• Non-consensual sex
• Consensual sex
• Needle sharing
• Not “standard of care”
6
Does PEP work?
• No randomized controlled studies
• Observational studies
• Studies with control groups
• Evaluations of PEP programs
• Indirect evidence
• Non-human primate (monkey) studies
• Prevention of mother-to-child transmission
7
How does PEP work?
• Infection does not occur instantly after an
exposure to HIV
• The virus needs to spread throughout
the body
• This may take up to 3 days after the
exposure
• The “window of opportunity” for PEP
• The brief period of time - after an
exposure - where infection has not yet
occurred
• During this time, PEP may be able to
stop HIV from causing an infection
8
How well does PEP work?
• We don’t know how protective PEP is
• We know it is not 100% protective
• People have become infected despite using PEP
• Protection likely depends on:
• Starting PEP quickly
• Being adherent
• The risk of transmission from the exposure
• Avoiding additional exposures
• The number and type of antiretrovirals used
9
Does occupational PEP work?
• Study details
• 712 healthcare workers exposed to HIV-infected blood
• Study findings
• 256 did use PEP
– 9 became infected
• 456 did not use PEP
– 24 became infected
PEP reduced the risk of HIV transmission by 81%
10
Does non-occupational PEP work?
• Study details
• 200 gay men in Brazil given a 4-day starter-pack of PEP
• Followed for over 2 years
• Study findings
• 68 men did use PEP after a high risk exposure
– 1 became infected
• 86 men did not use PEP after a high risk exposure
– 10 became infected
Study did not calculate effectiveness of nPEP
11
Failure of nPEP to prevent infection is rare
# People who used nPEP
# HIV infections
Amsterdam
261
5
France
776
1
Denmark
374
1
Australia
1552
0
Switzerland
710
0
San Francisco
702
6
~900
6
Montreal
It is difficult to interpret how protective PEP is…
• Would people have remained uninfected without
using PEP?
• Among those who became infected, was PEP used
correctly?
12
What’s involved in taking PEP?
1. Assessment
2. Counseling
3. Prescription
4. Follow-up
13
What’s involved in taking PEP?
1. Assessment
• Was the exposure within the last 72 hours?
• Is the exposed person HIV-negative?
• Was the exposure high-risk?
• What activity led to the exposure?
• What was the HIV status of the source person?
2. Counseling
3. Prescription
4. Follow-up
14
Guidelines for non-occupational PEP
• When is PEP recommended?
• Example, the CDC nPEP guidelines
• Is there a substantial risk from the activity?
– No  PEP not recommended
• If yes, was the exposure to someone who
was HIV-positive?
– No  PEP not recommended
– Unknown  Case-by-case basis
– Yes  PEP recommended
15
What’s involved in taking PEP?
1. Assessment
2. Counseling
• What are the risks and benefits of starting PEP?
• Is the exposed person ready to start PEP?
• Adherence and risk-reduction counseling
3. Prescription
4. Follow-up
16
What’s involved in taking PEP?
1. Assessment
2. Counseling
3. Prescription
• What antiretrovirals? How many?
• Starter-packs
4. Follow-up
17
Guidelines for non-occupational PEP
USA
Australia
WHO
Timing of PEP
Within 72 hours
Number of
antiretrovirals
2 or 3
What
antiretrovirals?
Two NRTIs
Two NRTIs + PI/NNRTI
Two NRTIs + tenofovir
UK
Europe
Within 48 hours
3
Two NRTIs
Two NRTIs + PI
Duration
Truvada + Kaletra
28 days
Barber and Benn 2010
NRTI = nucleoside reverse transcriptase inhibitor
NNRTI = non-nucleoside reverse transcriptase inhibitor
PI = protease inhibitor
Truvada = tenofovir + emtricitabine
Kaletra = Lopinavir
18
What’s involved in taking PEP?
1. Assessment
2. Counseling
3. Prescription
4. Follow-up
• Ongoing risk-reduction and adherence counseling
• Monitoring/management of side-effects and toxicity
• HIV testing
19
Why do so few people use nPEP in Canada?
• People may not think they are at risk
• Lack of national and provincial guidelines
• Use of nPEP is not promoted
• Only available in some emergency departments and
urgent care clinics
• Cost is only covered by some provincial and private
insurance plans
• Side-effects, adherence, monitoring, counseling
20
Why is there reluctance to make nPEP more
widely available?
• Feasibility
• Cost-effectiveness
• Risk compensation
21
Why is there reluctance to make nPEP more
widely available?
• Feasibility
• Research suggests that nPEP programs are feasible but
challenges exists
• Cost-effectiveness
• Research suggests that targeted nPEP programs are costeffective
• Risk compensation
• Research shows that there is little evidence of risk
compensation
22
Enhancing the potential benefit of PEP
•
Access to PEP provides an opportunity to offer additional
services to people at high risk of infection
•
Research study
•
Study details
– In addition to PEP, participants received either:
1. Standard risk-reduction counseling (2-sessions)
2. Enhanced risk-reduction counseling (5-sessions)
– Participants followed for a year after initiating PEP
•
•
Study findings
– Standard counseling  12.3% became infected
– Enhanced counseling  2.4% became infected
Combining PEP with enhanced risk-reduction counseling can
make it a more effective prevention tool
A comprehensive approach to PEP
• Integration into a comprehensive prevention program
• Targeted outreach and educational campaigns
• Prevention, care and support services
•
•
•
•
Adherence counseling and support
Risk-reduction counseling
Psychological counseling and trauma support
Mental health and addiction services
• Advocacy to improve access
24
Clinique l’Actuel: 9 years experience with nPEP
• Sexual health clinic in Montreal, Quebec
• Over 1,139 consultations
•
•
•
•
Prescribed to over 900 people
Majority of PEP users are gay men
80% first time using PEP
Average time to consultation after exposure - 29 hours
• Challenges
• 68% complained of side-effects
• 50% completed follow-up
• 6 HIV infections
• Many reported ongoing exposures
25
26
CATIE’s Programming Connection
27
CATIE Resources: PEP factsheet and article
28
29
30
Thank you!