title: Multiperson use of syringes among injection drug users in a needle exchange program: a gene-based molecular epidemiologic analysis.
abstract: Syringe-sharing behaviors among injection drug users (IDUs) are typically based on self-reports and subject to socially desirable responding. We used 3 short tandem repeat (STR) genetic biomarkers to detect sharing in 2,512 syringes exchanged by 315 IDUs in the Baltimore needle exchange program (NEP; 738 person-visits). Demographic characteristics as well as direct and indirect needle-sharing behaviors corresponding to the closest AIDS Link to Intravenous Experience (ALIVE) study visits were examined for association with multiperson use (MPU) of syringes. Overall, 56% of the syringes exchanged at the Baltimore NEP had evidence of MPU. Less MPU of syringes (48% vs. 71%; P < 0.0001) was seen with more rapid syringe turnaround (<3 days). IDUs always exchanging their own syringes ("primary" syringes) were less likely to return syringes with evidence of MPU (52%) than those who exchanged syringes for others ("secondary" syringes; 64%; P = 0.0001) and those exchanging primary and secondary syringes (58%; P = 0.004). In a multivariate analysis restricted to primary exchangers, MPU of syringes was associated with sharing cotton (adjusted odds ratio [AOR] = 2.06, 95% confidence interval [CI]: 1.30 to 3.28), lending syringes (AOR = 1.70, 95% CI: 1.24 to 2.34), and injecting less than daily (AOR = 0.64, 95% CI: 0.43 to 0.95). These findings support additional public health interventions such as expanded syringe access to prevent HIV and other blood-borne infections. Testing of STRs represents a promising approach to examining and accessing complex behavioral data, including syringe sharing.
authors.affiliation: Laboratory of Genomic Diversity, National Cancer Institute, NCI-Frederick, MD 21702, USA.
authors.forename: Sadeep
authors.initials: S
authors.lastname: Shrestha
authors.forename: Michael W
authors.initials: MW
authors.lastname: Smith
authors.forename: Karl W
authors.initials: KW
authors.lastname: Broman
authors.forename: Homayoon
authors.initials: H
authors.lastname: Farzadegan
authors.forename: David
authors.initials: D
authors.lastname: Vlahov
authors.forename: Steffanie A
authors.initials: SA
authors.lastname: Strathdee
mesh_terms: D000328:Adult; D000465:Algorithms; D015331:Cohort Studies; D004279:DNA, Viral / Q000032:analysis*; D005260:Female; D015658:HIV Infections / Q000453:epidemiology* / Q000517:prevention & control / Q000635:transmission; D015497:HIV-1 / Q000145:classification / Q000235:genetics*; D006801:Humans; D008297:Male; D008875:Middle Aged; D016485:Needle Sharing / Q000009:adverse effects / Q000706:statistics & numerical data*; D018671:Needle-Exchange Programs / Q000331:legislation & jurisprudence / Q000706:statistics & numerical data; D011446:Prospective Studies; D012309:Risk-Taking; D015819:Substance Abuse, Intravenous / Q000150:complications / Q000523:psychology*; D011795:Surveys and Questionnaires; D013594:Syringes / Q000009:adverse effects / Q000592:standards / Q000706:statistics & numerical data*; D020080:Tandem Repeat Sequences
chemical_list: D004279:DNA, Viral