Diana Rossi

Some data-driven reflections on priorities in AIDS network research.

Risk networks can transmit HIV or other infections; social networks can transmit social influence and thus help shape norms and behaviors. This primarily-theoretical paper starts with a review of network concepts, and then presents data from a New York network study to study patterns of sexual and injection linkages among IDUs and other drug users and nonusers, men who have sex with men, women who have sex with women, other men and other women in a high-risk community and the distribution of HIV, sex at group sex events, and health intravention behaviors in this network. It then discusses how risk network microstructures might influence HIV epidemics and urban vulnerability to epidemics; what social and other forces (such as “Big Events” like wars or ecological disasters) might shape networks and their associated norms, intraventions, practices and behaviors; and how network theory and research have and may continue to contribute to developing interventions against HIV epidemics.

High Seroprevalence of Bloodborne Viruses among Street-Recruited Injection Drug Users from Buenos Aires, Argentina

Injection drug use is the main mechanism of human immunodeficiency virus (HIV) transmission in Argentina (40% of reported AIDS cases in Argentina). This study was conducted among street-recruited injection drug users (IDUs) from Buenos Aires, with the aim of estimating seroprevalence and coinfection of HIV, hepatitis B virus (HBV), hepatitis C virus (HCV), and human T-lymphotropic viruses (HTLVs). A total of 174 volunteers participated in this study; 137 were men (78.7% of volunteers). The average age of the participants was 30 years. Only 64 of participants (37%) had no viral infection, whereas 110 (63%) were infected with > or =1 viruses. Seroprevalences were 44.3% for HIV, 54.6% for HCV, 42.5% for HBV, 2.3% for HTLV-I, and 14.5% for HTLV-II. Among the 77 HIV-infected persons, only 6.5% (5 persons) were not coinfected with other viruses; 88.3% (68) were coinfected with HCV and 68.8% (53) were coinfected with HBV. We demonstrated the existence of multiple viral infections with a high rate of prevalence in IDUs in Buenos Aires, Argentina.

Emerging future issues in HIV/AIDS social research

Peter Piot (Executive Director of UNAIDS) challenged Bangkok International AIDS Conference attendees to think ahead 10 years or more so we will be prepared to meet the challenges that will face us [1]. Over this next decade, many formidable challenges are likely to stem from the interactions of social, ecological, political, and economic change; existing social structures; the changing HIV epidemic, and changes produced by emerging biomedicine and viral evolution. Although some challenges will be unpredictable, we should plan ahead for those we are able to anticipate. This paper identifies important social research issues regarding the changing global epidemic so funding agencies, journal editors, social science communities, individual researchers and students, non-governmental organizations, communitybased organizations, and the general public can debate them and, hopefully, act on them.

Intersubtype BF recombinants of HIV-1 in a population of injecting drug users in Argentina.

Summary:The presence of recombinant intersubtypes of HIV-1 in Argentina has been reported since the mid-1990s. In this study, sequences of a region of the gag, pol, and vpu genes of HIV-1 were analyzed in samples of 21 injection drug users (IDUs) residing in the suburbs of the city of Buenos Aires. Genomic characterization and identification of recombination sites were made comparing the 3 regions with reference isolation sequences of subtypes B, F, C, A, and B/F recombinants: CRF12_BF and non-CRF12_BF sequences. Subtype assignment of the analyzed segments was phylogenetically confirmed. All the samples turned out to be BF recombinants in at least 1 of the 3 studied genes. Twelve samples (57%) had the same pattern as the Argentinean CRF12_BF, whereas in the rest, the pattern differed in at least 1 of the 3 genes. The relation of these fragments to the CRF12_BF was phylogenetically verified. These results indicate the predominance of BF recombinants and the presence of a high percentage of sequences closely related to the CRF12_BF in the IDU population in Argentina and suggest a possible association between viral variants and the transmission route.

Multiple infections and associated risk factors among non-injecting cocaine users in Argentina

The aim of this study was to estimate the seroprevalence rates of human immunodeficiency virus (HIV), hepatitis B virus (HBV, core antibody), hepatitis C virus (HCV), and syphilis infections and analyze associated risk factors among 504 non-injecting cocaine users (NICU) in Buenos Aires, Argentina. Participants were interviewed in face-to-face sessions through a short structured questionnaire. Using venipuncture, 10 mL of blood was collected. Seroprevalence rates were: HIV (6.3%), HBV (9%), HCV (7.5%), and VDRL (4.2%). The risk of being infected with HIV, HBV, and HCV was significantly associated with having had a sex partner who was either a drug injector or who was known to be HIV positive. HIV and HCV infections were associated with former imprisonment, and HCV was associated with having been tattooed. Because of the rising number of NICU and the multiple infections detected, it is essential to implement prevention strategies focused on this population.

Theory, measurement and hard times: some issues for HIV/AIDS research.

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.ResumenLa inestabilidad económica y política y los “grandes eventos” asociados con ella están muy extendidas en todo el mundo. Los “grandes eventos” a veces conducen a brotes epidémicos de VIH, y a veces no, y no entendemos por qué. Las actuales teorías del comportamiento no abordan adecuadamente estos procesos, y por lo tanto no pueden proveer una óptima orientación para una efectiva intervención. Basándonos en parte en una crítica a nuestro modelo de las “vías” que se interconectan durante los grandes eventos, sugerimos que la Teoría de la Actividad Histórico-Cultural (CHAT en ingles) puede proporcionar un marco útil para la investigación del VIH en esta área. Utilizamos conceptos de CHAT y también sugerimos una serie de áreas en las que las nuevas medidas se deben desarrollar para hacer posible este tipo de investigación.

Hepatitis C virus among non-injecting cocaine users (NICUs) in South America: can injectors be a bridge?

AIM To investigate the factors associated with hepatitis C virus (HCV) infection among non-injecting cocaine users (NICUs) and to compare practices associated with HCV and HIV infection. DESIGN An intercountry cross-sectional study. Setting  Buenos Aires and Montevideo metropolitan areas. PARTICIPANTS A total of 871 NICUs. MEASUREMENTS NICUs were interviewed and their blood was drawn and used for HCV, HIV, HBV surface antigen (HbsAg), HB-anticore and Venereal Disease Research Laboratory (VRDL) antibody assays. Bivariate and multivariate logistic regression analyses included comparisons of HCV and HIV mono-infected participants with HCV-HIV seronegatives. FINDINGS Prevalence rates were 8.8 [95% confidence interval (CI): 6.9-10.8) for HCV and 7.9 (95% CI: 6.1-9.7) for HIV. HCV-infected NICUs were twice as likely as HCV-HIV seronegatives to have shared straws for cocaine snorting or sniffing, even when adjusted for other variables. HCV prevalence rates ranged from 3.6% among NICUs who denied sharing straws and having had an injection drug user (IDU) or an HIV-positive sexual partner to 12.6% among participants who reported ever having shared straws or having had either an IDU- or HIV-positive sexual partner (χ(2) (trend)  = 6.56, P = 0.01). CONCLUSIONS Non-injecting cocaine users from South America are vulnerable to multiple infections and HCV infection appears to occur through the sharing of straws. HCV infection is associated with intimate relationships with IDUs or HIV-seropositive partners, supporting the hypothesis that HCV risk may be due primarily to risk-taking behaviour associated with drugs in this population.

HIV seroincidence estimates among at-risk populations in Buenos Aires and Montevideo: use of the serologic testing algorithm for recent HIV seroconversion.

Summary: Using the serological testing algorithm for recent HIV seroconversion, we estimated annualized incidences (per 100 person-years) of HIV-1 infection in different at-risk groups in Buenos Aires and Montevideo, during a 5-year period between 1998 and 2003. HIV-positive serum samples from 9 serosurveys conducted among men who have sex with men, patients attending clinics for a sexually transmitted infections consult (STIs), female commercial sex workers, injecting drug users (IDUs), noninjecting cocaine users (NICUs), asymptomatic women screened for HIV infection, and patients with tuberculosis were used. HIV incidences were as follows: 6.7 for men who have sex with men, 2.0 for STIs, 1.3 for female commercial sex workers, 0.0 for Argentinean IDUs, 10.3 for Uruguayan IDUs, 3.1 for Argentinean NICUs, 4.4 for Uruguayan NICUs, and 2.4 for patients with tuberculosis. Among asymptomatic women screened for HIV infection, incidence rose from 0.4 in 1998 to 4.6 in 1999 and to a high of 10.2 in the year 2000. Unexpectedly, high HIV incidences were detected among at-risk groups in Buenos Aires and Montevideo. This pattern shows an emerging HIV epidemic among heterosexuals stemming from core HIV-infected at-risk groups. There is an urgent need for development and implementation of specific prevention strategies to address this burgeoning epidemic.

The HIV/AIDS epidemic and changes in injecting drug use in Buenos Aires, Argentina

This article discusses the changes in injecting drug use from 1998 to 2003 in Buenos Aires, Argentina. The Rapid Situation Assessment and Response methodology was used to obtain the information. Quantitative and qualitative techniques were triangulated: 140 current IDUs and 35 sex partners of injection drug users (IDUs) were surveyed; 17 in-depth interviews with the surveyed IDUs and 2 focus groups were held, as well as ethnographic observations. The way in which risk and care practices among injecting drug users changed and the influence of the HIV/ AIDS epidemic on this process are described. In recent years, the frequency of injection practices and sharing of injecting equipment has decreased, while injecting drug use is a more hidden practice in a context of increasing impact of the disease in the injecting drug use social networks and changes in the price and quality of drugs. Knowledge about these changes helps build harm reduction activities oriented to IDUs in their particular social context.

Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome Prevention in Injection Drug Users and Their Partners and Children: Lessons Learned in Latin America—The Argentinean Case

Thirty-nine percent of Argentineans living with acquired immunodeficiency syndrome were infected with human immunodeficiency virus through the injection of drugs. However, it was not until the 1990s that harm reduction programs were created. Research and outreach projects have been developed to identify and interact with the hidden injection drug user (IDU) population. Implementation of rapid assessment and response methodology contributed to the founding of Argentinas first syringe exchange program. Community-based outreach is the appropriate method for working with the impoverished population of Buenos Aires. Seroprevalence studies and focused prevention campaigns targeting IDUs and their sex partners and children have been developed. Collaborations between government and nongovernmental organizations in various cities supported the distribution of prevention and harm reduction messages to 900 IDUs within a 3-month period. Ongoing research, community-based interventions, and collaborative work among different organizations allow for more frequent and more consistent contact with the IDU population of Argentina.