By Erin Sherbert
By Erin Sherbert
By Leif Haven
By Erin Sherbert
By Chris Roberts
By Kate Conger
By Brian Rinker
By Rachel Swan
The Watters paper is based on 5,644 surveys of needle-exchange clients conducted over a five-and-a-half -year period by the Urban Health Study (UHS), a San Francisco group that he chairs. UHS reports as estimated 13,000 to 16,000 IDUs in San Francisco, and has dedicated itself to surveying addict populations since 1985. Conducting what Watters calls "very open-ended, freewheeling interviews," the researchers ask IDUs about their AIDS knowledge and HIV/AIDS risk behaviors, and get them to confide their medical histories and their drug-use histories, as well as their sexual histories.
"In our ethnographic studies, we didn't find evidence of a ritualized practice," says Watters. "What people consistently told us was ... they had to [share], they couldn't carry a syringe with them because they'd be arrested by the police. And it's a pretty big hassle to be sick in prison."
Watter's group gathered enough baseline information on San Francisco's IDU population to examine the effectiveness of needle exchange. Additional questions were added to the interviews with IDUs through a fairly random process: Some would be proposed in formal meetings, some over a cup of coffee.
"We did realize that because we had studied IDUs before needle exchange started in S.F., we were in a really unique position to be able to look at some of the effects, whether positive or negative," says Jennifer Lorvick, another of the paper's authors.
Watters' effort required intense, interminable data-crunching. The 5,600-odd UHS records were transferred to a data base and crunched by a mainframe at UC Berkeley, says Lorvick.
"It's a huge data set, and every step is time-intensive," she says. "You have to create a clean set of data to work with."
The operation is analogous to weeding an overgrown meadow until it's bare of everything but ragweed, then asking questions like, "Do all ragweed plants grow near rocks of that size? Is that because of the rock, or something about the plant? And what's the sun got to do with all this?" This is the way scientists work - you can't assume the sun has anything to do with plant growth - and they've got to be skeptical about the questions they ask and the answers they get.
Watters, Lorvick says, "wanted to be very conservative [and] stick to the data. If [researchers] don't do that, they have no credibility."
After months of statistical weeding, Watters and company's data showed that by fall 1990, survey respondents were reporting that they used the needle exchange more frequently than the black market or other sources. Those numbers held through spring 1992, at the end of the survey, when 45 percent of the respondents were "usually" obtaining their syringes from an exchange (32 percent relied on the black market and 23 percent used other sources like pharmacies, diabetic acquaintances, or friends).
"I think that probably the most important finding of the paper," Lorvick says, "was the relationship between using the needle exchange and not sharing needles. That was the thing that just kind of popped out, like, Bang! There's our finding."
The data-crunch also indicated that needle exchanges weren't "recruiting" new drug users, noting that the mean age of IDUs increased from 35.8 to 41.6 over the five-and-a-half years of Watters' study, and that the percentage of those saying they'd started injecting druges within the previous year dropped from 3 percent to 1.1 percent.
In one sample of exchanged needles, UCSF researchers found that 7 percent were HIV-contaminated. Extrapolating the data, the authors calculated that 3,600 infected syringes were removed from circulation in a single month in 1992, when Prevention Point was still unfunded by the city and operating illegally. The numbers have surely risen since then, though no one has the resources to conduct another survey.
It's anybody's guess how many infections were staved off by the needle exchange. What's clear is the dynamic and dangerous link between IDUs and the transmission of AIDS. In San Francisco, 9 percent of those diagnosed with AIDS were IDUs who engaged in same-sex sex, according to May 1995 statistics from the Department of Public Health. Through the middle of 1993, the federal Centers for Disease Control found that 24 percent of all diagnosed AIDS cases were among heterosexual IDUs. In 3 percent of adult AIDS diagnoses, the sole risk factor was having an IDU as a sex partner. And better than half of all pediatric AIDS cases were traced to IDU mothers or mothers whoh ad sex with IDUs.
The epidemiological moral is that a little needle exchange now saves a huge amount of money later. The lifetime cost to treat an adult San Franciscan with AIDS can reach $250,000, says Sara Kershnar of the San Francisco-based Harm Reduction Coalition group. Prevention Point's budget for distributing needles at nine sites was just $450,000 kast year. If needle exchange prevents as few as two cases of AIDS a year, the program has paid for itself - not to mention the other infections that it can help prevent. Complications caused by hepatitis B can require a lover transplant, which costs about $300,000.
It's clear by now that the smart money should be placed on preventing incurable infectious diseases. Without needle exchange, says John Watters, "Your tax bill goes up and your daughter gets sick, or your cousin or your nephew or your nephew's cousin."