This article presents an analysis of the correlates of HIV status among samples of injection drug users (IDUs) in Lang Son Province, Vietnam (n=348), and Ning Ming County, Guangxi Province, China (n=294), who were interviewed and tested for HIV antibody just before the start of a peer-based HIV prevention intervention in this border region. Participants were largely male, in their 20s, and single. Logistic regression analysis suggests that among Chinese IDUs, border-related factors (eg, living closer to the border, buying drugs across the border more frequently) and younger age are the best predictors of HIV positivity. In Vietnam, HIV status seems to drive behavior (eg, some risk reduction practices are predictive of HIV positivity). These differing patterns may reflect the fact that the intertwined epidemics of heroin injection and HIV began earlier and HIV prevalence has reached significantly higher levels in Lang Son than across the border in Ning Ming. Although border-related factors emerge as predictors in Ning Ming, more IDUs in Lang Son are HIV-positive and may be reacting behaviorally to that status. Their greater likelihood of engaging in risk reduction measures may reflect some combination of a belief that risk reduction can slow disease progression and an altruistic desire to avoid infecting others.

We report the use of liquid electrode plasma-atomic emission spectrometry (LEP-AES) in protein sensing studies employing Ag nanoparticle labeling. LEP-AES requires no plasma gas and no high-power source and is suitable for onsite portable analysis. Human chorionic gonadotropin (hCG) was used as a model target protein, and the immunoreaction in which hCG is sandwiched between two antibodies, one of which is immobilized on the microwell and the second is labeled with Ag nanoparticles, was performed. Sensing occurs at the narrow pass in the center of a quartz chip following oxidative dissolution of the Ag nanoparticles by nitric acid. hCG was analyzed in the range from 10 pg/mL to 1 ng/mL, and the detection limit for hCG was estimated at 1.3 pg/mL (22.8 fM). The proposed detection method has a wide variety of promising applications in metal-nanoparticle-labeled biomolecule detection.

Background: To assess patterns of injecting drug use and HIV prevalence among injecting drug users (IDUs) in an international border area along a major heroin trans-shipment route.