“Understanding differences in HIV/HCV prevalence according to differentiated risk behaviors in a sample of PWID in rural Puerto Rico.” Journal of Harm Reduction 13 (10): 1-7.
Roberto Abadie, Melissa Welch-Lazoritz, Camila Gelpi-Acosta, Juan Carlos Reyes, Ric Curtis, Kirk Dombrowski
Blood contained in needles and injection equipment has been identified as a vector for HIV and HCV transmission among people who inject drugs (PWID). Yet, there is often a wide discrepancy in prevalence for both viruses. While microbiological differences between viruses influence prevalence, other variables associated with the way drugs are acquired and used, also play a role.
Respondent-driven sampling (RDS) methods recruited a sample of 315 current intravenous drug users in rural Puerto Rico. Information about type and frequency of use, HIV and HVC risk behaviors (sharing needles, cookers, cotton, and water), sexual behaviors, and alcohol use was collected. HIV and HCV statuses were assessed via rapid antibody tests. T tests compare means of participants who tested positive (reactive) to those who tested negative. Logistic regression analyses were used to validate the association of the risk factors involved.
Tests showed a significant difference in HIV (6 %) and HCV (78.4 %) prevalence among a population of current PWID. The main risk behaviors in HCV transmission are the sharing of injection “works”, (e.g., cookers, cotton, and water). Sharing works occurred more than twice as often as the sharing of needles, and HCV+ and HCV? individuals reported the same needle sharing habits.
Theory, Measurement and Hard Times: Some Issues for HIV/AIDS Research
Samuel R. Friedman, Milagros Sandoval, Pedro Mateu-Gelabert, Diana Rossi, Marya Gwadz, Kirk Dombrowski, Pavlo Smyrnov, Tetyana Vasylyeva, Enrique R. Pouget, David Perlman
Economic and political instability and related “big events” are widespread throughout the globe. Although they sometimes lead to epidemic HIV outbreaks, sometimes they do not—and we do not understand why. Current behavioural theories do not adequately address these processes, and thus cannot provide optimal guidance for effective intervention. Based in part on a critique of our prior “pathways” model of big events, we suggest that cultural–historical activity theory (CHAT) may provide a useful framework for HIV research in this area. Using CHAT concepts, we also suggest a number of areas in which new measures should be developed to make such research possible.
Keywords: Big events, Hard times, Cultural–historical activity theory, Theory, HIV Measurement
Topological and Historical Considerations for Infectious Disease Transmission among Injecting Drug Users in Bushwick, Brooklyn (USA)
Kirk Dombrowski, Richard Curtis, Samuel Friedman, and Bilal Khan
Recent interest by physicists in social networks and disease transmission factors has prompted debate over the topology of degree distributions in sexual networks. Social network researchers have been critical of “scale-free” Barabasi-Albert approaches, and largely rejected the preferential attachment, “rich-get-richer” assumptions that underlie that model. Instead, research on sexual networks has pointed to the importance of homophily and local sexual norms in dictating degree distributions, and thus disease transmission thresholds. Injecting Drug User (IDU) network topologies may differ from the emerging models of sexual networks, however. Degree distribution analysis of a Brooklyn, NY, IDU network indicates a different topology than the spanning tree configurations discussed for sexual networks, instead featuring comparatively short cycles and high concurrency. Our findings suggest that IDU networks do in some ways conform to a “scale-free” topology, and thus may represent “reservoirs” of potential infection despite seemingly low transmission thresholds.
Keywords: Social Network Analysis; Injecting Drug Users; Scale-Free Networks
On November 16, 2012, SNRG’s NYC National HIV Behavioral Surveillance (NHBS) IDU3 team concluded its third tri-annual round of interviews, and HIV and hepatitis B/C testing, with injection drug users (IDU) in New York City. More than 500 study participants were interviewed and tested at one of the three NYC NHBS field sites in Bushwick, Brooklyn; the Lower East Side, in Manhattan; and Mott Haven, in the Bronx.The NHBS study is a national CDC study conducted in cities with high rates of HIV prevalence that each year recruits a sample of a population at high risk for HIV (IDU, men who have sex with men, and heterosexuals at elevated risk for HIV). As in many SNRG studies, the study used respondent-driven sampling (RDS), a chain-referral strategy where study participants recruit future study participants. HIV and hepatitis B and C tests, and risk-reduction counseling were provided to all participants who agreed to testing. Participants were compensated for study participation and recruiting. Following the cyclical design of the NHBS, the SNRG NHBS team is now preparing for 2013 data collection with heterosexuals at elevated risk for HIV, in collaboration with the NYC Department of Health and Mental Hygiene, and the CDC. For a map of the recruitment click here.
PI: Holly Hagan (NYU)
Investigators: Bilal Khan and Kirk Dombrowski
Hepatitis C virus (HCV)-related deaths now exceed HIV-related deaths in the US. Throughout the world, HCV is hyperendemic in people who inject drugs (PWID). New outbreaks of acute HCV infection are unfolding in HIV-positive men who have sex with men (MSM) and in 15-24 year olds who have transitioned from abuse of prescription opioids to illicit opiate injection. In patients with chronic HCV infection, 20-25% will develop liver disease which may manifest as cirrhosis, liver failure or hepatocellular carcinoma (HCC). The prognosis for HCC is extremely poor, and HCV is the chief etiologic agent for this type of cancer. Recent discoveries in HCV prevention and treatment provide a great opportunity to reverse the trend toward increasing rates of HCV, HCV/HIV co-infection, and HCC. This study will use the methods of Implementation Science – research synthesis, mathematical modeling and simulation, and comparative effectiveness analyses – to determine how best to constitute a portfolio of interventions for the prevention and control of HCV and its consequences while taking into account limited resources and underlying epidemiologic and social network features. A dissemination plan will make extensive use of technology, including social media, and guidance from key stakeholders. These are our specific aims:
1. Synthesize evidence characterizing a) transition from misuse of prescription opioids to drug injection, b) HCV epidemiology and prevention for PWID and HIV+ MSM, and c) progression and treatment of HCV disease in these two groups, to derive best estimates to populate our HCV natural history and transmission models.
2. Use agent-based modeling to estimate the effects of scale-up of individual and combined prevention- and treatment-related interventions on HCV transmission and natural history in PWID and HIV+MSM.
3. Determine the combination of interventions for particular budget and epidemiologic scenarios that a) minimizes acute and chronic HCV infections, including HIV/HCV co-infection, b) prevents the greatest number of cases of HCV-related HCC and other serious sequelae, c) maximizes life expectancy and quality-adjusted life expectancy and d) reduces health disparities.
4. In collaboration with our Dissemination Advisory Board, apply an integrated knowledge-exchange approach to providing our target audiences (policymakers, public health and harm reduction practice communities, PWID and HIV+MSM) with the knowledge and tools to implement evidence-based HCV control strategies or reduce personal risk of infection and its consequences.
The broad objective of this study is to provide an evidence base to guide allocation of scarce public resources in the US and other countries where HCV is principally transmitted among PWID. This will be accomplished by synthesizing, modeling and translating very recent developments in HCV epidemiology, prevention and treatment into practical tools to optimize population health.