The 131st Annual Meeting (November 15-19, 2003) of APHA

Abstract #64512

William A. Zule, DrPH¹, Wendee Wechsberg, PhD², Wendy K.K. Lam, PhD², and Winnie Luseno². (1) Substance Abuse Treatment Evaluations and Interventions, RTI International, PO Box 12194, 3040 Cornwallis Drive, Research Triangle Park, NC 27709-2194, 919.485.2797, zule@rti.org, (2) Substance Abuse Treatment Evaluations and Interventions, Research Triangle Institute, PO Box 12194, 3040 Cornwallis Drive, Research Triangle Park, NC 27709-2194

Concerns about injecting drug risk associated with HIV have overshadowed the near saturation of hepatitis C virus (HCV) infection among injectors. Injection equipment is part of the equation in understanding rapid HIV spread. Injecting drug users (IDUs) use two different types of syringes, dead space syringes which retain 84 ml and integral cannula syringes which retain 2 ml of fluid with the plunger depressed. In laboratory experiments comparing the two types of syringes, following two 0.5 milliliter rinses with water, dead space syringes retained over 1 ml of blood while integral cannula syringes retained less than 0.001 ml of blood. This difference of over 1,000 fold is an order of magnitude larger than the differences in viral load observed in different stages (acute, latent, end-stage/AIDS) of HIV disease. This may be important because mathematical models of HIV epidemics suggest that the acute stage of infection may account for a disproportionate number of new infections. This presentation uses simple mathematical models to illustrate the impact of the different types of syringes on the course of HIV and HCV epidemics among IDUs. HIV and HCV prevalence and behavioral risk data from two cities are then used to assess model fit and calibrate the models. The models suggest that syringe type may be a critical factor in determining the course of HIV but not HCV epidemics among IDUs. These findings have important implications for prevention efforts targeting IDUs.

Learning Objectives:

Following this session the participant will be able to:
• Describe the three characteristics of needles and syringes that influence risk for HIV transmission.
• Recognize the importance of assessing characteristics of injection equipment as well as risk behaviors in evaluating HIV risk among injectors.

Keywords: Injection Drug Users, HIV Risk Behavior

Presenting author's disclosure statement:
I do not have any significant financial interest/arrangement or affiliation with any organization/institution whose products or services are being discussed in this session.