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Substance Use Research Strategy
Overview
While declines in HIV/AIDS incidence and
mortality have occurred in several developed countries, HIV transmission
among injecting drug users (IDUs) and other drug users remains an urgent and
expanding public health problem in many regions of the world. In fact, the
majority of new HIV infections in Eastern Europe, Russia, and South East
Asia are attributable to injection-related risk behaviors. Rapid HIV
transmission among IDUs in low prevalence settings is leading to new
epidemics in many countries. Thus, there is significant epidemiologic
relevance to prevention efforts targeting IDUs. The mechanisms of
transmission are reasonably clear, although new drugs and contexts arise,
especially in international settings, and need to be investigated for
formulating and tailoring interventions.
The Substance Use Scientific Committee's scope of work includes:
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Preventing
transmission through injection drug use and sexual transmission of HIV
among injection and non-injection substance users (e.g., alcohol, crack
cocaine, and other non-injection drugs) |
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Developing
and refining primary and secondary prevention interventions for
HIV-infected drug users |
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Evaluating
interventions designed to overcome structural and community level
barriers to accepting and implementing effective HIV prevention
strategies |
Background and
Rationale
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Persons
using illicit drugs, especially by the parenteral route, are at high risk
for HIV infection. Numerous studies have been conducted on IDUs, and it is
clear that multi-person reuse of needles and syringes represents a primary
mechanism for HIV transmission. Sharing drug preparation equipment and
injection equipment, either directly or indirectly, results in higher risk
of infection. |
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Sexual
transmission and related risk behaviors, including exchange of sex for
drugs or money, have been independently associated with HIV infection
among injection and non-injection drug users. |
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Individuals
who participate in effective treatments for substance abuse reduce the
frequency of their drug use, which reduces the incidence of drug related
risk behaviors.
In turn, lower rates of drug related risk behaviors result in fewer
exposures to HIV and fewer infections. |
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Interventions
known to be effective in reducing HIV risk behaviors involve community
outreach, access to sterile syringes, and drug abuse treatment. |
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Structural
interventions and those that target communities and the social networks of
drug users are considered to be of the highest priority. |
In
1997, the NIH Consensus Development Conference on HIV Prevention summarized
effective approaches to use with IDUs, based on behavioral and biological
outcomes. The primary approaches include community outreach (including
indigenous outreach leaders), needle exchange, and drug abuse treatment
(including methadone).
While studies using behavioral outcomes are numerous, data on HIV
seroconversion as an outcome are few, and none have been the result of a
randomized clinical or community trial. Given the many reports that show
these interventions are effective, the ethical considerations of a
randomized design need to be carefully weighed and considered (e.g.,
comparing different methods is more acceptable than a no-treatment
arm).
While
considerable published research demonstrates the efficacy of needle exchange
programs, and government sponsored reports in the U.S. and elsewhere have
acknowledged the science exists to support implementation of the
interventions, many communities have been reluctant to accept such programs
as part of a comprehensive HIV prevention program. Only a few states have
followed the lead of Connecticut and put in place laws that permit pharmacy
access to syringes and needles; recently such a law has been enacted in New
York. While
HPTN studies are not able to directly fund needle exchange components, the
Substance Use Scientific Committee is intent on designing studies that are linked to programs that provide
access to sterile injection equipment.
In
many areas, there is public and political reluctance to use methadone
maintenance therapy, which has been shown to be safe and effective in the
treatment of heroin dependence and is associated with reductions in HIV risk
behaviors and infection.
In Russia, for example, it is illegal to use methadone or other
agonist therapies to treat heroin dependence.
This reluctance is rooted in the perception of this treatment as
ineffective and merely substituting one drug for another.
Consequently, alternative treatment strategies that address concerns
with methadone may have a greater likelihood of implementation, such as
buprenorphine/naloxone.
It has become increasingly important to consider such alternative
approaches that can be used in developed and underdeveloped countries.
Key public health questions to be addressed
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What
are the most effective behavioral approaches that are theory-driven
(using cognitive-behavioral, affective, peer outreach, network/support
group or hybrid strategies) directed at both drug and sex-related risk
behaviors? |
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How
can behavior change strategies be paired with biomedical approaches
(treatment of STDs, use of microbicides and drug treatment) to reduce
sexual transmission of HIV and drug related risk behaviors? |
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What
is the best approach or combination of approaches to implementing
social/environmental programs that incorporate needle exchange to reduce
parenteral transmission,
syringe exchange programs, pharmacy sales, physician prescription, and/or
improving access to other HIV prevention services, and modifying drug
abuse treatment to optimize access/adherence to reduce parenteral
transmission? |
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How
will the changing nature of the HIV epidemic among drug users effect the
implementation of interventions in such areas and in countries where
potential biomedical drug treatments are illegal? |
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Can
an intervention targeting HIV infected IDUs to serve as peer leaders
among their IDU network result in a reduction on HIV seroincidence? |
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Can interventions
targeting the sexual transmission of HIV among drug using individuals
reduce incidence and limit the "bridging" of HIV to non-drug
using populations? |
HPTN Substance Use Studies
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HPTN 033 |
HIV Prevention Preparedness Study |
(Closed to Follow Up) |
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HPTN 037 |
A Phase III Randomized Study to Evaluate the Efficacy of a Network-oriented Peer Educator Intervention for the Prevention of HIV Transmission Among Injection Drug Users And Their Network Members |
(Closed to Follow Up) |
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HPTN 058 |
A Phase III randomized controlled trial to evaluate the efficacy of drug treatment in prevention of HIV infection among opiate dependent injectors |
(Enrolling) |
HPTN Substance-use Scientific
Committee Contacts
Dave
Metzger, Chair, University of Pennsylvania
Bonnie Dye, Family Health International
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