Syringe services for people who inject drugs are enormously effective, but remain underused

By Nora D. Volkow

Nearly 30 years of research show that providing testing, counseling, and sterile injection supplies to people who inject opioids and other drugs helps prevent transmission of infectious diseases, without increasing drug-related or other crimes in the vicinity. Contrary to worries that syringe services programs (SSPs) will encourage or promote drug use, evidence shows that they more often do the opposite, linking people with addiction to effective treatment and even helping prevent overdose deaths.

Unfortunately, prejudices against harm-reduction continue to impede the reach of SSPs. Some states and communities continue to resist or even shut them down, even though history shows that the effects of such prejudice can have a disastrous impact on public health. December 1 is World AIDS Day, an opportunity to underscore the solid science behind the efficacy of this important harm-reduction measure.

The common belief that SSPs encourage more drug use is contradicted by the data. One study in Seattle, for instance, found that people who had used an SSP were about three times more likely to substantially reduce their drug injections or stop injecting altogether than those who didn’t, over one year of follow-up. Partly, this is due to these programs facilitating clients staying in treatment for their addiction or even by providing that treatment. SSPs can be an important tool for reaching people who otherwise are less likely to seek or stay in SUD treatment because of unemployment or homelessness. People who had used SSPs in the Seattle study were 60% more likely to stay in methadone treatment over the year, and current SSP clients were five times more likely to enter methadone treatment compared to never-clients. Another study in Baltimore found an especially strong effect of SSP usage on later drug treatment among people living with HIV.

Drug use contributes to the spread of HIV and other infectious diseases like hepatitis B and C in multiple ways, including the sharing of drug injection equipment. Use of SSPs can reduce infectious disease transmission both by reducing needle sharing and by providing or linking people to addiction treatment, which can reduce drug use along with infection transmission behaviors associated with it, such as condom-less sex.

Use of SSPs in places where they have been allowed to operate in the United States is associated with a 40-60% reduction in HIV transmission. Evidence on transmission of hepatitis C virus (HCV) is less clear, but in Europe, where SSPs are more widely used, high SSP use is associated with a 76% reduction in HCV transmission.

In the current drug landscape dominated by high-potency synthetic opioids like fentanyl, SSPs also help prevent fatal overdoses. Overdose education and naloxone distribution (OEND) is the cornerstone of overdose prevention, and research suggests it is less costly to implement OEND in SSPs than it is in large health systems, SUD treatment programs, or other community settings, in part because SSP staff may have more experience and knowledge of its use.

SSPs also may distribute fentanyl test strips. In one study, more than 70% of SSP clients in Baltimore and Delaware reported using test strips obtained from their SSP to check for fentanyl in what they were injecting. In Delaware, over two thirds of clients (69%) reported that getting a positive result with a fentanyl test strip led them to change their drug-taking practices by using less than they would have otherwise, going slower, asking someone to check on them, or taking other precautions.

Some SSPs provide referrals to buprenorphine treatment for people with opioid use disorder or provide buprenorphine treatment onsite. At the IDEA Exchange SSP based in Miami, clients are able to initiate buprenorphine treatment and receive their medication there, as well as receive motivational interviewing from peers. Peers facilitate ongoing telehealth visits with their clinicians, which was found to greatly facilitate staying in treatment. While stigma and discrimination drive many people living with HIV to discontinue their antiretroviral treatment, IDEA Exchange clients also reported staying in care because staff were welcoming and non-judgmental.

The oft-heard claim that SSPs increase crime in the surrounding neighborhood is another prejudice that is contradicted by available evidence. One study found no increase in drug-related arrests in the vicinity of a Baltimore SSP in the year after it opened, relative to other areas of the city. Another study found no association between proximity to an inner-city SSP in Harlem and experiences of violence. Studies conducted in Canada and Australia, where people can legally obtain syringes as well as use illicit drugs under supervision at overdose prevention centers, have found no increases in drug-related crimes, robberies, or thefts associated with those facilities. 

Overdose prevention centers are a somewhat different and less-studied harm-reduction service, but they also provide sterile syringes and have similar associated stigma. A recent study analyzing crime reports in an undisclosed U.S. city found a faster decline in reports of assault, burglary, larceny, and robbery in the vicinity of an unsanctioned overdose prevention center over the five years after it opened in 2014 than in other areas. Another study found no change in crime or disorder associated with two government-sanctioned overdose prevention centers in New York City that opened in 2021.

Besides concerns over crime, there has also been a concern that SSPs may lead to more syringe litter, but this too is contradicted by evidence. One NIDA-funded study found an eight-fold greater quantity of improperly disposed syringes in a major city without SSPs compared to a major city with SSPs. In another study, people who received syringes from an SSP were half as likely to dispose of them improperly compared to people who got them from other sources such as pharmacies.

Failure to offer these kinds of services can have disastrous consequences, as was shown a decade ago in Scott County, Indiana: Sluggishness to permit the opening of an SSP allowed an unmitigated outbreak of HIV among people who injected drugs in that rural community. According to a 2018 modeling study, at least 127 infections could have been prevented had an SSP opened two years sooner than it did. A 2014 study funded in part by NIDA found that modest increases in national funding for SSPs would have an enormous return on investment: An additional $10 million invested per year (in 2011 dollars) was estimated to save $76 million in treatment costs—a 7.6-fold return on investment.

Participants in a study of SSP operators and health officials in rural Kentucky said that people in their community who were skeptical of the concept of harm reduction sometimes came around when they saw these approaches as ways to help people with different life circumstances or “meet people where they are”. Infectious disease transmission and other adverse outcomes of substance use are liable to increase when we fail to meet people with addiction where they are and put compassionate, science-supported solutions in place. SSPs are one of the best-studied and solidly supported approaches to HIV prevention and should be utilized widely as part of a comprehensive public-health approach to the drug crisis.

View Nora's blog on NIDA's website.