Syringe-mediated drug-sharing (backloading): a new risk factor for HIV among injecting drug users.
BACKGROUND
In syringe-mediated drug-sharing (backloading), injecting drug users (IDU) use their syringes to mix drugs and to give measured shares to other IDU by squirting drug solution into the syringes of other IDU. Backloading has been discussed as a potential HIV risk factor, but its role as an HIV transmission route has not been established empirically.


METHODS
Six hundred and sixty IDU who had injected drugs in the previous 2 years were street-recruited from Bushwick, New York City through chain referral, tested for HIV antibody and interviewed about sexual and drug-risk behaviors.


RESULTS
Receiving drugs via backloading in the previous 2 years was reported by 24.5% of the subjects. These subjects had significantly higher HIV seroprevalence than those who did not receive drugs by backloading (odds ratio, 2.2; 95% confidence interval, 1.5-3.1). Backloading remained positively and significantly associated with HIV seropositivity in stepwise logistic regression, and in a series of simultaneous logistic models controlling for sociodemographic variables and for sexual and drug risk variables.


CONCLUSIONS
Backloading can be a route of HIV transmission among IDU and should be incorporated into risk-factor studies and HIV transmission modeling. Many IDU who avoid other high-risk drug-injection practices may overlook the risk of backloading. HIV prevention programs should warn IDU against syringe-mediated drug-sharing and work together to develop ways to avoid it.
Jose
B
B
National Development and Research Institutes, Inc., New York, New York 10013.
Friedman
S R
SR
Neaigus
A
A
Curtis
R
R
Grund
J P
JP
Goldstein
M F
MF
Ward
T P
TP
Des Jarlais
D C
DC
D000328:Adult; D016001:Confidence Intervals; D005260:Female; D015658:HIV Infections / Q000453:epidemiology / Q000635:transmission*; D006679:HIV Seropositivity / Q000453:epidemiology; D006801:Humans; D008297:Male; D016485:Needle Sharing; D016017:Odds Ratio; D012307:Risk Factors; D012725:Sexual Behavior; D015819:Substance Abuse, Intravenous; D013594:Syringes