In this study, the risk of having been infected with HIV, HBV, and HCV was greater in Newark than in NYC, even after controlling for possible city confounders. Among African-American/black or Hispanic participants, populations that historically have had higher HIV infection rates than whites,37,40
the risk of having been infected was also greater in Newark. However, the prevalence of HCV was disturbingly high in both cities.
As expected, there were dramatic differences in syringe acquisition sources. Almost none of the Newark IDUs obtained syringes from legal sources, while almost all of those in NYC did. However, most IDUs in Newark obtained syringes that they considered “new” from other sources, particularly from street sales and from friends or relatives. IDUs in Newark, out of necessity, appear to have adapted to a risk environment in which sterile syringes were not legally available by obtaining syringes that they believed were “new” from other, potentially unsafe sources. Although we did not test such “new” syringes for HIV or hepatitis viruses, there is a risk that at least some of the illegal “new” syringes acquired by IDUs in Newark, particularly those from street sellers, who have no local access to sterile syringes from legal syringe distribution programs, may have been used previously and repackaged for sale.41,42
The city differences in injecting risk behaviors that involved the direct sharing of syringes indicate that IDUs in Newark are at greater risk of injecting with syringes previously used by other injectors. They were also more likely to reuse their own syringes, which would increase their likelihood of acquiring bacterial infections, and possibly injecting with syringes that other injectors may have used but of which they were unaware. Assuming that at least some of the illegal, “new” syringes diverted from other sources are sterile, there was still insufficient “new” syringe coverage43
in Newark from these “gray market” sources, since IDUs in Newark were more than five times more likely not to have always injected once only with a new sterile syringe that had been sealed in a wrapper. “Indirect” injecting equipment-sharing practices (e.g., sharing cookers) to prepare and distribute the drug solution were considerable in both cities and may account for the very high prevalence of HCV and substantial prevalence of HBV in both cities, since these pathogens can be efficiently transmitted through sharing drug preparation equipment.44
In addition, since HBV is also efficiently transmitted through sex, unprotected sex with high-risk sex partners may have contributed to the substantial prevalence of HBV.45
Even in cities with sterile syringe distribution programs, more needs to be done to prevent HBV and HCV infection among drug users. Specifically, given the high transmissibility of HBV and HCV, public health agencies, SEPs, and other harm reduction organizations need to place greater emphasis on protecting drug users from sharing drug preparation equipment in addition to sharing syringes46
and on promoting hygienic injecting practices and preventing unsafe sex. Moreover, since an effective, safe, and inexpensive vaccine is available against HBV, greater efforts are needed to facilitate wider HBV vaccine coverage and uptake among drug users.
One of the limitations of the study is the possibility of an “ecological fallacy” in which the aggregate association of city differences in the legality of syringe distribution programs with infection seroprevalence, syringe sources, and injecting risk behaviors may not be reproduced at the individual level.47
However, in this study, we controlled for several variables that may be potential confounders of city differences. Moreover, the findings from this study are confirmed by most of the studies conducted at the individual level, as cited previously, which demonstrate that IDUs who obtain their syringes from SEPs or other legal sources are at lower risk of parenterally transmitted HIV and other blood-borne infections than IDUs who do not. However, because only two cities were examined, the ability to generalize from the data is limited. A larger, multilevel study of the effect of city differences in the legality of sterile syringe distribution and in program implementation would provide a greater understanding of both city and individual effects (and their interaction) on injecting risk behaviors. With cross-sectional data, the temporal direction between city differences in sterile syringe provision and individual differences in injecting risk behaviors and infection cannot be definitively determined. However, the difference in legal syringe distribution between NYC and Newark predated by many years the recruitment of the sample and the period in which risk behaviors were measured. In addition, longitudinal studies, for example, in NYC by Des Jarlais et al.1
and in Chicago by Huo and Ouellet,10
have found that the use of SEPs is protective against HIV and parenteral infection risk for HBV and HCV. The use of self-report data may have contributed to the underreporting of more stigmatized behaviors, such as sharing syringes, although the bias may have been similar in both samples. While the methods used for sampling and recruiting in this study have been used by many other studies of nondrug treatment-recruited drug users, the sample is nonrandom, so that generalizations from the study’s findings must be informed by an understanding of this possible limitation.
The efficacy of legally providing sterile syringes to IDUs to prevent infection with HIV and other blood-borne infections is supported by most studies that have examined the issue.48
Moreover, other studies have found that sterile syringe programs are not associated with an increase in the initiation or resumption of injecting drug use.48–52
The legal provision of sterile syringes is also likely to have long-term consequences for reducing infection risk among IDUs.10
Our present study provides yet further evidence that the provision of legal sterile syringes reduces the risk of HIV and other blood-borne infections. Similarly, in an earlier international comparison of HIV seroprevalence in cities with and without SEPs, the average annual change in seroprevalence was 11% lower in cities with SEPs than in cities without them.53
The disparities in infection prevalence and injecting risk behaviors between IDUs in Newark and NYC underscore the critical need to fully implement legal sterile syringe distribution programs in NJ and in other jurisdictions in the USA with minimum delay. In Newark, which has the most HIV/AIDS cases of any city in New Jersey, injection drug use accounted for 47% of 13,045 cumulative cases, followed by 31% for heterosexual contact, much of which is through sexual contact with IDUs.54
In the 12-month period from July 1, 2005 through June 30, 2006, injection drug use directly accounted for 21% of 346 newly diagnosed HIV infections in Newark,55
whereas in NYC, it directly accounted for 7% of 1,879 newly diagnosed HIV infections reported in 2005 among African-Americans and Hispanics combined.56
Given the extremely high HIV disease burden in New Jersey from injecting drug use, the rapid implementation of legal sterile syringe distribution programs for IDUs is a necessary and prudent public health initiative with proven efficacy that is strongly justified by the science. Although the continuation of restrictions on the use of federal funds for sterile syringe distribution is inconsistent with the recommendations of public health agencies in the USA7,30–32
the implementation of legal sterile syringe distribution programs at the state and local level, such as those in NYC and potentially in Newark, can prevent avoidable infections with HIV and hepatitis among IDUs.