Study shows injection drug users at needle exchange program share few syringes, and those who do, share with friends

Public health researchers say disease prevention efforts must educate remaining needle-sharers to stop the risky practice

LOS ANGELES, Feb. 28 � Most injection drug users who use community needle exchange programs�which aim to reduce the risk of illness spread through tainted needles�do not share their needles, according to public health researchers at the Keck School of Medicine of the University of Southern California and the New York Academy of Medicine.

Sharing needles raises the risk for spreading diseases such as HIV and hepatitis B and C, but a number of drug users interviewed in a two year-long study still persisted in sharing needles with close friends, the researchers wrote in the March issue of the American Journal of Public Health.

"Although needle exchange programs have provided a needed service in permitting access to sterile syringes to injection drug users who cannot or will not stop injecting, these data suggest that programs need to renew efforts to discourage further sharing of syringes obtained from the program," the researchers wrote.

Study authors Thomas W. Valente, Ph.D., and David Vlahov, Ph.D., conducted the study while both were with the School of Hygiene and Public Health at Johns Hopkins University. Valente is now associate professor of preventive medicine at the Keck School of Medicine of USC, and Vlahov is with the Center for Urban Epidemiologic Studies at the New York Academy of Medicine.

The researchers examined risky behavior among 1,184 injection drug users who visited a needle exchange program in Baltimore between 1995 and 1997. They asked participants about their drug use and gathered information about the participants� network of friends and their recent habits (whether they injected drugs, shared syringes, had sex or drank alcohol together).

Researchers note that the program succeeded in reducing needle sharing overall. Of the 1,184 users, only 203 (about 17 percent) reported they had recently shared a syringe. In other studies of the same population, needle sharing occurred among 70 percent of users in 1990, but declined to less than 25 percent of users in 2000.

Of the 203 users who said they had recently shared a syringe, 159 (or 78 percent) reported sharing it with a friend. Users did not take risks randomly; rather, they were more likely to share syringes with close friends.

When drug users confine their drug use to a circle of close friends, in a population with low prevalence of disease, they protect themselves from contracting disease to an extent, the researchers noted. But users changed friends often during the study, increasing the risk of disease. Prevalence of disease, such as hepatitis C, in the needle exchange program population also was high�increasing the risk of infection.

Injection drug use is a serious problem in the United States, according to the Centers for Disease Control and Prevention. Through 1996, one third of all reported AIDS cases in the U.S. could be traced to injection drug use.

"Needle exchange may reduce the degree of syringe sharing that occurs because of legal restrictions and costs, but so far, it hasn�t eliminated risk due to syringe sharing for social or ritualistic reasons," Valente said. "Injection drug users still feel compelled to share syringes with their close friends. They consume alcohol and drugs with their friends, and refusal to share a syringe in such settings would indicate a lack of trust among friends."

Vlahov said disease prevention efforts need to improve education to get drug users to not share needles at all.

"Clearly, stopping drug use is a goal, but for those who won�t or who can�t stop drug use, using a clean needle each time they inject and not sharing with others is key to HIV prevention," Vlahov said. "Among those who share, it tends to happen more among friends. People working in HIV prevention need to get the message out that sharing with friends might seem natural and safe, but that isn�t necessarily so. It is safer to use your own needle, and even safer to stop injecting altogether."