An Evidence Based Review of Needle Exchange
Needle/syringe exchange programs (NEP) were developed nearly 20 years
ago in the
A
review of the reports published in the literature from 1994 through mid-2003
was conducted to determine whether the widely proclaimed success of NEPs in
preventing or reducing HIV transmission among IDUs was supportable with “hard”
data. A search of Medline on the National Library of Medicine’s web-site for
journal articles published after Jan.1, 1994 on needle/syringe exchange
programs yielded hundreds of citations.
The exclusion of editorials, letters, news items and review articles as
well as other articles that lacked abstracts revealed few cohort studies of
NEPs whose design and results might allow evaluation of their efficacy in
reducing HIV transmission. Data on the hepatitis viruses, Hepatitis B (HBV),
and Hepatitis C (HCV), were considered surrogates for HIV when incorporated
into an NEP study. Those selected should have been able to show differences in
viral seroprevalence between users of needle/syringe exchange and non-users,
reduction in viral incidence, or show differences in an endpoint such as
mortality.
At
the time most of these studies were inaugurated it was thought that risky
injection behavior such as needle sharing was the principle route of HIV
transmission among IDUs. Now, however, high-risk sexual behavior is recognized
to be equally important. It is reasonable to assume, nevertheless, that NEPs
should confer some measurable protective effect at least if the participants
use them regularly and avoid risky injection practices.
Seven reports out of the total were identified which by design might provide a credible measure of the effectiveness of NEPs in preventing or reducing HIV, HBV, or HCV transmission among IDUs.
Epidemiological Studies
Researchers in
Results from a cohort study in
Looking back now, it appears likely that many, if not most, of the
infections during the on-going epidemic were the result of sexual transmission
rather than needle sharing.
A study
was reported that measured the impact of HIV and other risk factors on mortality
in a cohort of IDUs and non-injecting drug users in
Another
report from
A study
of needle exchange programs in
The
virological efficacy of a needle exchange program in
The results of a 10-year study of initially HIV negative male and
female IDUs in
Three of the above studies also measured the effect of methadone maintenance on HIV transmission but all failed to show a beneficial effect.
Other
Studies
In
May 2001, the Canadian Bureau of HIV/AIDS, STD and TB’s Update Series published
an article in Health
1.
The sharing of
drug injection equipment remains unacceptably high among IDUs.
2.
The level of reported,
unprotected sexual intercourse is also high among IDUs.
3.
Needle exchange
programs alone are not sufficient to prevent HIV transmission among IDUs and
should be complemented with a range of appropriate additional services.
Studies
conducted at
At the time of enrollment, the prevalence of HCV among participants was already 82% and had reached 92% by 2001 – near saturation. According to an earlier report published in 2001, 124 of the participants had died since the study’s inception in 1996;
28 deaths were attributed to HIV/AIDS
41 died of drug overdose
55 died of other causes
(Wood E, et al. CMAJ 2001; 165(4); 405-410).
Although needle sharing is an important
means of HIV transmission among IDUs, the study found that the proportion of
IDUs who reported needle sharing (27.6%) did not decrease during the next 5
six-month follow-up visits. This was seen in spite of the availability of the
large needle-exchange program serving the participants. The authors concluded
that needle sharing remained an alarmingly common practice in the cohort. An
article published in 2005 again expressed alarm and called for action on the
rising incidence of HIV and HCV infections in
A
recent study compared the HIV prevalence rates among heroin sniffers, new
heroin injectors and long term heroin injectors (Chitwood E, et al. J Psychoactive Drugs 2003; 35 (4): 445-453). The study
population consisted of 900 heroin users equally divided into 3 groups; heroin
sniffers, new heroin injectors and long-term heroin injectors. New heroin
injectors were defined as those who had initiated injection during the previous
four years, and long-term injectors were defined as those who had initiated
injection prior to January 1, 1984, when it was assumed that the risks of infection
with HIV were still unknown. The HIV prevalence rate among sniffers and new
injectors was nearly the same, about 13%. The rate among long-term heroin
injectors was almost double that, nearly 25%. The higher rate among long-term injectors was attributed to a
maintained level of risky sexual activity over time as well as to the sharing
of needles and drug paraphernalia. The authors attributed slightly more than half of the
increased HIV prevalence among long-term IDU to high-risk injection behaviors,
attributing the remainder to high-risk sexual activity. Race and ethnic group
were important variables as determinants of the risk of infection. Hispanics
were almost three times as likely to be HIV positive as non-Hispanic whites and
African-Americans were over five times as likely to be infected as non-Hispanic
whites. Men who had sex with men were at increased risk for infection with HIV
compared to men who had sex with women only. A history of crack cocaine use
among sniffers of heroin was also associated with higher rates of HIV
infection. The authors stress that any interventions such as needle exchange
must stress sexual risk as a component equal to that of injection.
Another report by some of the same authors studied HIV prevalence rates among heroin sniffers with no history of drug injection (Sanchez J, et al. AIDS Care. 2002; 14(3): 391-398). Here the HIV prevalence rate among men was 8.7% while among women the rate was more than double, 18.1%.
Both articles stressed the
importance of sexual behavior in the high rates of HIV transmission among
heroin addicts. As in the
Relevant
Studies of Cocaine
A number of studies have been reported on the effects of cocaine, both crack and injected, on sexual behavior. One of these found that HIV antibody seroconversion among women was higher among crack users than non-crack or injection users (Webber MP et al. Arch AIDS Res. 1991; 5(1-2): 45-47).
The strongest predictor of seroconversion was prostitution.
The study reported that cocaine use in any form was associated with very
high-risk heterosexual activity.
A second report cited the effects of drug counseling in four different
treatment groups on sexual behavior of 487 cocaine dependant patients (Woody
GE, et al. J Acquir Immune Defic Syndr.
2003; 33(1): 82-87). Most of the patients, 79%, were crack users. The most
common HIV risks were having sex with multiple partners and unprotected sex.
After six months of therapy cocaine use fell dramatically to an average 1 day
per month and was associated with an average 40% reduction in HIV risk behavior
across all treatment, gender and ethnic groups. Most of the reduction was a
result of having fewer sexual partners and less unprotected sex.
Researchers at
Although part of the problem in
the seven needle/syringe exchange studies cited here may in some instances have
been a less than adequate number of needles and syringes supplied to the IDUs
(the CDC has estimated that on average an IDU uses over 1000 sets a year) the main
problem appears to have been the high level of risky sexual and injection
behaviors practiced by both male and female IDUs. The
While it is possible that
needle/syringe exchanges might have some effect in reducing the rate of HIV
transmission among their participants, it is fair to say that NEP were not
measurably effective in limiting the spread of HIV, HBV or HCV in any of the
studies reviewed here. Some of them like those in
Vancouver, Seattle, and Baltimore had been operating in areas that lacked basic
public health programs such as HIV name reporting and partner notification,
programs usually used for control of serious sexually transmitted infections.
The needle exchange and counseling apparently were the primary means of
"harm reduction."
A number of other articles were found during this literature search that were designed to show an effect of NEP in reducing HIV transmission by changing injection risk behavior, but they failed to provide hard evidence to substantiate such a reduction. Only a few presented seroprevalence or incidence data in support of their behavioral findings.
One of
the studies presenting seroprevalence data used an inappropriate statistical
method in data analyses to achieve a significant result (Des Jarlais DC, et al.
Lancet 1996; 348: 987-91). The authors used meta-analysis of three very
disparate groups to show a statistically “significant” difference between NEP
participants and non-participants.
Another
study used HIV recovery rates in discarded syringes as surrogates for IDU to
estimate the annual incidence of new HIV infections in NEP participants in
A
national study was conducted in
One
study compared changes over time in HIV seroprevalence in injecting drug users
worldwide. The authors compared seroprevalence rates from published and
unpublished sources in 81 cities with and without NEPs. The average annual
change in seroprevlence was 11% lower in cities with NEPs (Hurley SF, et al. Lancet 1997; 349: 1997-1800).
Some of
the studies show an impact of the NEPs on reducing risk behavior such as needle
sharing among participants. The data, however, is based primarily on
self-reporting by individual IDU either on questionnaires or by face-to-face
interviews. The reliability of self reported behavior by addicts is always open
to question under the best of circumstances. While informative this data lacks
the probative effect of confirming the risk reduction by, for instance,
comparing HIV seroconversion rates among the study participants.
In
another study, primary health care services were provided for 551 street sex
workers, 89% of whom injected drugs, during 1992-94 in
Comment:
Without
intervention and treatment both heroin and cocaine addiction can last for
years, for many, particularly heroin, a lifetime ( Hser Y, et al. Arch Gen Psychiarty. 2001; 58: 503-508). Although some studies have indicated that among heroin
addicts a process of “maturing out” to abstinence takes place among a major
proportion of the addict population, a recent report from the Amsterdam study
cohort raises questions about the frequency of this process (Termorshuizen F,
et al. Am J Epidemiol. 2005;
161(3): 271-279). The authors state that although
they found a favorable trend towards abstinence in the cohort, the high
mortality rates and the low prevalence of abstinence among those who survived
over the long term indicate that the concept of natural recovery, “maturing
out”, to a drug free state doesn’t apply to a substantial portion of the addict
population. This suggests that for many addicts a need for needles, whether
clean or not, will persist for years, even decades. Early in the course of this pandemic, it seemed that
needle/syringe exchange programs might provide an effective intervention in the
growing epidemic of HIV disease among drug injectors; however, hard evidence to
show this is lacking. Without credible evidence of efficacy, the provision of
clean needles and syringes appears primarily to support the individual’s
addiction and, with it, drug related high-risk behavior.
There
is no easy way to intervene in an epidemic that feeds on the injection of
mind-altering drugs and their associated high-risk injecting and sexual
behaviors. Although injecting illicit drugs is harmful to both the user and to
society, the HIV epidemic that was spawned by this practice has become a public
health disaster. Since the beginning
of the epidemic, there have been nearly 210,000 reported cases of AIDS in
injection drug users and 77,000 cases reported among their sexual contacts (Center for Disease Control and Prevention
HIV/AIDS Surveillance Report 2002). Incomplete
data for 2002 indicated there were nearly 11,000 new HIV/AIDS cases reported in
the
Ideally, every individual who is HIV infected should receive evaluation and be considered for appropriate antiretroviral (ARV) therapy. Therapy and/or monitoring will be necessary for the rest of the individual’s life. A large percentage of HIV infected IDU; however, fail to undergo appropriate treatment after their infection has been diagnosed ( Celentano DD, et al. AIDS. 2001; 15(13): 1707-1715, Sherer R. JAMA. 1998; 280: 567-568, Strathdee SA, et al. JAMA. 1998; 280: 547-549).
In the large
Heroin
injectors who accept treatment with methadone or buprenorphine are more likely
to adhere to ARV therapy than are cocaine injectors for whom there is as yet no
medical treatment. Because of this a high percentage of cocaine dependent
injectors and crack users who are HIV infected remain untreated. Access to
health care is important and IDU who have health insurance coverage, for
example, are more likely to undergo treatment both for their drug dependency
and for their HIV infection. Untreated or improperly treated infections will
continue to serve as a rich reservoir of HIV for transmission within
communities of injection drug users.
The
cumulative costs in money and lives of the IDU HIV epidemic are already large
and will continue to grow absent effective intervention. The energy and resources
used for free-standing needle/syringe exchange programs should be redirected to
support the creation of badly needed additional drug treatment and
rehabilitation services. The outreach performed by the NEPs should be replaced
by outreach from substance abuse programs acting as liaison for drug treatment
programs and linked to public health HIV prevention and treatment services.
Existing public health, disease prevention, and control programs should be
strengthened with active HIV surveillance in areas where injection drug use is
known to be prevalent. IDU who become infected with HIV should be referred for
appropriate treatment for their drug dependence as well as for ARV therapy. Far
from reducing harm, simply bringing needle/syringe exchange into this maelstrom
only adds more fuel to the fire.
Fred J.
Payne, MD, MPH
2/21/2006
Source:
Children's AIDS Fund