Genetic diversity and HIV-1 incidence estimation among cocaine users in São Paulo, Brazil

Health outcomes associated with crack-cocaine use: Systematic review and meta-analyses

BACKGROUND

Crack-cocaine use is prevalent largely in socio-economically marginalized populations in the Americas. Its use has been associated with diverse health outcomes, yet no recent or systematic reviews of these exist.

METHODS

A systematic review of health outcomes associated with crack-cocaine use was performed, using MEDLINE, Scopus, Web of Science, CINAHL, PsycINFO, and LILACS up to October 2016. Search terms included crack-cocaine and health outcome-related keywords, targeting peer-reviewed studies on quantified health outcomes associated with crack-cocaine use. Random effects meta-analyses produced pooled odds ratios. Levels of evidence for major results were assessed using the GRADE approach. A review protocol was registered with PROSPERO (CRD42016035486).

RESULTS

Of 4700 articles returned, 302 met eligibility criteria, reporting on health outcomes for 14 of 22 ICD-10 chapters. Conclusive evidence and meta-analyses showed positive associations between crack-cocaine use and blood/sexually transmitted diseases (HIV and hepatitis C virus, others); moderate evidence and meta-analyses supported associations with neonatal health, and violence. There were mixed associations for mental and other health outcomes, yet insufficient evidence to perform meta-analyses for many categories (e.g., mortality). Most underlying research was of limited or poor quality, with crack-cocaine commonly assessed as a secondary covariate.

CONCLUSIONS

Crack-cocaine use was associated with a range of health outcomes, although it was unclear if there was direct causal impact, interactions between risk factors, or external drivers of both crack-cocaine use and outcomes. Rigorous epidemiological studies are needed to systematically assess health outcomes of crack-cocaine use and underlying pathways, also to inform evidence-based interventions.

Estimated incidence and genotypes of HIV-1 among pregnant women in central Brazil

OBJECTIVE

To estimate the incidence of HIV-1 infection among pregnant women from central-western Brazil.

DESIGN

Observational cross-sectional study.

METHODS

A total of 54,139 pregnant women received antenatal HIV screening from a network of public healthcare centers in 2011. The incidence of confirmed HIV-1 infection was estimated using the Serological Testing Algorithms for Recent HIV Seroconversion (STARHS) methodology and BED-capture enzyme immunoassay (BED-CEIA). The yearly incidence was calculated, and adjusted incidence rates were estimated. For a subgroup of patients, protease and partial reverse transcriptase regions were retrotranscribed from plasma HIV-1 RNA and sequenced after performing a nested polymerase chain reaction.

RESULTS

Of the participants, 20% had a pregnancy before the age of 18 and approximately 40% were experiencing their first pregnancy. Of the 54,139 pregnant women screened, 86 had a confirmed HIV-1 diagnosis, yielding an overall prevalence of 1.59 cases per 1000 women (95% CI 1.27-1.96). A higher prevalence was detected in the older age groups, reflecting cumulative exposure to the virus over time. Among the infected pregnant women, 20% were considered recently infected according to the BED-CEIA. The estimated incidence of HIV infection was 0.61 per 1000 person-years (95% CI 0.33-0.89); the corrected incidence was 0.47 per 1000 person-years (95% CI 0.26-0.68). In a subgroup of patients, HIV-1 subtype C (16.7%) was the second most prevalent form after subtype B (66.7%); BF1 recombinants (11.1%) and one case of subtype F1 (5.5%) were also detected.

CONCLUSION

This study highlights the potential for deriving incidence estimates from a large antenatal screening program for HIV. The rate of recent HIV-1 infection among women in their early reproductive years is a public health warning to implement preventive measures.

HIV genotypes and primary drug resistance among HIV-seropositive blood donors in Brazil: role of infected blood donors as sentinel populations for molecular surveillance of HIV

BACKGROUND

There are few surveillance studies analyzing genotypes or primary (transmitted) drug resistance in HIV-infected blood donors in Brazil. The aim of this study was to characterize patterns of HIV genotypes and primary resistance among HIV-seropositive donors identified at 4 geographically dispersed blood centers in Brazil.

METHODS

All HIV-infected donors who returned for counseling at the 4 REDS-II Hemocenters in Brazil from January 2007 to March 2011 were invited to participate in a case-control study involving a questionnaire on risk factors. Viral sequencing was also offered to positive cases to assign genotypes and to detect and characterize primary resistance to reverse transcriptase and protease inhibitors according to World Health Organization guidelines.

RESULTS

Of the 341 HIV-seropositive donors who consented to participate in the risk factor and genetics study, pol sequences were obtained for 331 (97%). Clade B was predominant (76%) followed by F (15%) and C (5%). Primary resistance was present in 36 [12.2%, 95% confidence interval (CI) 8.2 to 15.5] of the 303 individuals not exposed to antiretroviral therapy, varying from 8.2% (95% CI: 2.7 to 13.6) in Recife to 19.4% in São Paulo (95% CI: 9.5 to 29.2); there were no significant correlations with other demographics or risk factors.

CONCLUSIONS

Although subtype B remains the most prevalent genotype in all 4 areas, increasing rates of subtype C in Sao Paulo and F in Recife were documented relative to earlier reports. Transmitted drug resistance was relatively frequent, particularly in the city of Sao Paulo which showed an increase compared with previous HIV-seropositive donor data from 10 years ago.

Addiction research centres and the nurturing of creativity. National institute on alcohol and drugs policies, Brazil

The National Institute of Public Policy for Alcohol and Other Drugs (INPAD) is based at the Federal University of São Paulo, Brazil, and was created to collect scientific evidence regarding epidemiology, develop new therapeutic approaches, study health economics and provide education to subsidize the proper measures to change the Brazilian scenario of alcohol and drug consumption. Policies directed towards the control of alcohol and drugs in Brazil are fragmented, poorly enforced and therefore ineffective. The unregulated market of alcohol in Brazil has contributed to the worsening health of the Brazilian population. Since 1994, INPAD has participated actively in academic debates and discussions about alcohol and drug policies and their effects on the political welfare of the country. Many scientific papers and books have been published on this subject, and the internet and other media have provided excellent opportunities for the dissemination of specialized information to the general population.

Estimates of HIV-1 incidence based on serological methods: a brief methodological review

The paper reviews the serological methods employed in the estimation of HIV incidence based on cross-sectional studies, as well as the main findings from studies carried out in Brazil that have used such methods. Each method is briefly described, as well as their advantages and limitations. The different methods are also analyzed as a set of complementary but sometimes contradictory strategies under permanent criticism and review, still far from a gold standard. Finally, an additional question--central to the accurate monitoring of the AIDS epidemic using such methods--is discussed: whether the different methods should or should not be adjusted. The debate is open and controversy should be viewed as an unavoidable consequence of a very dynamic research field, informed by the progress in sciences as diverse as epidemiology, biostatistics, mathematical modeling and different branches of basic science, such as immunology, virology, and molecular biology.

HIV prevalence among female sex workers, drug users and men who have sex with men in Brazil: a systematic review and meta-analysis

Background

The Brazilian response towards AIDS epidemic is well known, but the absence of a systematic review of vulnerable populations ─ men who have sex with men (MSM), female sex workers (FSW), and drug users (DU) remains a main gap in the available literature. Our goal was to conduct a systematic review and meta-analysis of studies assessing HIV prevalence among MSM, FSW and DU, calculating a combined pooled prevalence and summarizing factors associated the pooled prevalence for each group.

Methods

Nine electronic databases (MEDLINE via PubMed, EMBASE, Cochrane CENTRAL, AIDSLINE, AMED, CINAHL, TOXNET, SciELO, and ISI-Web of Science) were searched for peer-reviewed papers published in English, French, Spanish or Portuguese, from 1999 to 2009. To be included in the review, studies had to measure HIV prevalence and/or incidence as the primary outcome among at least one specific population under analysis.

Results

The studies targeting the three populations analyzed mostly young participants aged 30 years or less. Among FSW, eight studies were selected (3,625 participants), consistently identifying higher condom use with sexual clients than with occasional and stable partners. The combined HIV prevalence for FSW was 6.2 (95% CI: 4.4-8.3). Ten studies targeting MSM were identified (6,475 participants). Unprotected anal intercourse was commonly reported on those studies, but with great variability according to the nature of the relationship - stable vs. occasional sex partners - and sexual practice - receptive vs. insertive anal sex. Pooled HIV prevalence for MSM was 13.6 (95% CI: 8.2-20.2). Twenty nine studies targeting DU were identified (13,063 participants). Those studies consistently identified injection drug use and syringe/needle sharing as key predictors of HIV-infection, as well as engagement in sex work and male-to-male sex. The combined HIV prevalence across studies targeting DU was 23.1 (95% CI: 16.7-30.2).

Conclusions

FSW, MSM and DU from Brazil have a much risk of acquiring HIV infection compared to the general population, among which HIV prevalence has been relatively low (~0.6%). Those vulnerable populations should be targeted by focused prevention strategies that provide accurate information, counseling and testing, as well as concrete means to foster behavior change (e.g. access to condoms, drug abuse treatment, and clean syringes in the case of active injecting drug users), tailored to gender and culture-specific needs. Programs that provide these services need to be implemented on public health services throughout the country, in order to decrease the vulnerability of those populations to HIV infection.

Cocaine effects on mouse incentive-learning and human addiction are linked to alpha2 subunit-containing GABAA receptors

Because GABA(A) receptors containing alpha2 subunits are highly represented in areas of the brain, such as nucleus accumbens (NAcc), frontal cortex, and amygdala, regions intimately involved in signaling motivation and reward, we hypothesized that manipulations of this receptor subtype would influence processing of rewards. Voltage-clamp recordings from NAcc medium spiny neurons of mice with alpha2 gene deletion showed reduced synaptic GABA(A) receptor-mediated responses. Behaviorally, the deletion abolished cocaine's ability to potentiate behaviors conditioned to rewards (conditioned reinforcement), and to support behavioral sensitization. In mice with a point mutation in the benzodiazepine binding pocket of alpha2-GABA(A) receptors (alpha2H101R), GABAergic neurotransmission in medium spiny neurons was identical to that of WT (i.e., the mutation was silent), but importantly, receptor function was now facilitated by the atypical benzodiazepine Ro 15-4513 (ethyl 8-amido-5,6-dihydro-5-methyl-6-oxo-4H-imidazo [1,5-a] [1,4] benzodiazepine-3-carboxylate). In alpha2H101R, but not WT mice, Ro 15-4513 administered directly into the NAcc-stimulated locomotor activity, and when given systemically and repeatedly, induced behavioral sensitization. These data indicate that activation of alpha2-GABA(A) receptors (most likely in NAcc) is both necessary and sufficient for behavioral sensitization. Consistent with a role of these receptors in addiction, we found specific markers and haplotypes of the GABRA2 gene to be associated with human cocaine addiction.

Origin and evolutionary history of HIV-1 subtype C in Brazil

OBJECTIVE

To investigate the origin and to reconstruct the onset date of the HIV-1 subtype C epidemic in Brazil.

DESIGN

Three independent datasets of subtype C sequences isolated from HIV-1-positive patients from southern Brazil over a period of 15 years (1991-2006) were analyzed: 82 env V3 sequences (213 nt), 40 env C2-C5 sequences (559 nt), and 72 pol sequences (960 nt).

METHODS

Brazilian sequences were compared with other subtype C reference strains from the database using basic local alignment search tool, phylogenetic analyses, and searching of specific amino acid signature patterns. Evolutionary parameters were estimated using a Bayesian coalescent-based method under either strict or relaxed molecular clock models.

RESULTS

HIV-1 subtype C sequences from Brazil and Burundi formed a monophyletic cluster at both env and pol regions and shared specific amino acid signatures in the protease region when compared with other viruses of the same subtype from around the world. All Brazilian strains arose as a monophyletic subcluster within the Burundi-Brazilian lineage, whereas isolates from Burundi appeared at the origin of the clade. Evolutionary analyses of both env and pol genomic regions indicate that the age of the most recent common ancestor of the Brazilian subtype C clade dates back to the early 1980s.

CONCLUSION

The subtype C epidemic in the southern Brazilian region was initiated by the introduction of a single founder strain closely related to subtype C strains from Burundi. Our results suggest that this founder event probably took place around the early 1980s, roughly a decade before the previous estimates.

J, Holzmayer V, Swanson P, Vallari A, Yamaguchi J, Devare S, Pedroso C, Ramos A, Badaro R. HIV-1 strains identified in Brazilian blood donors: significant prevalence of B/F1 recombinants

In the Brazilian HIV-1 epidemic subtypes B, C, and F1 are cocirculating in the high risk population groups, and there is a high prevalence of intersubtype recombinant forms. The dynamic nature of the HIV epidemic in Brazil led us to study HIV-1 subtypes present in HIV-infected blood donations collected from 2001 to 2003. Donations from 91 seropositive donors were evaluated. Genetic subtype was obtained for 88 specimens based on sequence analysis of gag p24, pol IN, and env gp41 IDR. HIV-1 subtype B was the predominant strain present in the donor population (73.9%). A significant prevalence of intersubtype recombinants of subtypes B and F1 was found (22.7%). Subtype C (1.1%) and F1 (2.3%) were rare. None of the B/F1 recombinants is CRF28_BF or CRF29_BF. The high level of unique B/F1 recombinant strains in this population demonstrates the dynamic and complex nature of the HIV epidemic in Brazil.

Association analysis of GRK3 gene promoter variants in cocaine abuse

The G protein-coupled receptor kinase 3 gene (GRK3) is a candidate gene for cocaine addiction because it is involved in the regulation of several neurotransmitter receptors, including the response to dopaminergic agonists such as methamphetamine and cocaine. We hypothesized that genetic variants in the GRK3 gene might be associated with an increased risk of cocaine addiction. To test this, we genotyped three variants located in 5' untranslated and promoter regions of the gene in a sample of 711 cocaine users and 862 healthy control individuals from Sao Paulo, Brazil. Genotypic, allelic and haplotypic analyses provided no evidence for an association between alleles at these polymorphisms and cocaine abuse in this sample. Population stratification was tested for and its effect corrected for, but this did not affect the association test results. In conclusion, our results do not support a major role for GRK3 gene promoter variants in cocaine addiction.

Human immunodeficiency virus type-1 subtypes of infected patients in Espírito Santo, Brazil

Genetic variability of human immunodeficiency virus type-1(HIV-1) is a potential threat for both diagnosis and treatment of HIV/AIDS, as well as the development of effective vaccines. Up to now, HIV subtypes circulating among HIV-positive patients in the state of Espírito Santo were not known. In the present study, blood samples from 100 therapy-naïve HIV-1 infected patients were collected and the HIV subtype was determined through the Heteroduplex Mobility Assay (HMA). Ninety-seven out of 100 studied samples were subtyped by HMA, 73 samples (75.2%) were from subtype B, 9 (9.3%) from subtype F, 3 (3.1%) from subtype C, 6 (6.2%) Benv/Fgag, and another 6 (6.2%) Fenv/Bgag, what suggests that recombinant viruses were present in the studied samples. Twenty-eight percent of the subtype B samples were represented by the Brazilian B" subtype, which were identified by RFLP with Fok I. Data presented here demonstrate that the epidemiological characteristics of the HIV epidemic in the state of Espírito Santo are similar to those from the other Southeastern states and helped to better understand the genetic polymorphism of HIV in Brazil.

Serological and molecular typing of HIV type 1 infection in the Tiriyo tribe, a native Indian community of the Amazon region of Brazil

The seroprevalence and the occurrence of an HIV-1 subtype was assessed in blood samples of the Tiriyo tribe. Antibody was found in 0.6% and the molecular analysis of the pro region detected the emergence of a subtype B for the first time in a native Indian tribe of the Amazon region of Brazil.

Crack users, sexual behavior and risk of HIV infection

OBJECTIVE: To compare a sample of injecting cocaine users and crack users, assessing sexual behavior, risk for infection by HIV and its seroprevalence. METHOD: 109 injecting cocaine users and 132 crack users were assessed, using the World Health Organization questionnaire from the expanded "Cross-Site Study of Behaviors and HIV Seroprevalence among Injecting Drug Users" and HIV serology. Data were assessed by Multiple Correspondences Analysis. RESULTS: Crack users showed less time of drug consumption when compared to the injecting cocaine users. Despite this fact, they had higher rates of risky sexual activity, differences in poli-consumption of drugs, and higher rates of involvement in illegal issues. HIV seroprevalence among crack users, although lower than for injecting cocaine users (7% vs. 33%) is high when compared to the general population at the same age. CONCLUSIONS: Sexual behavior of crack users in the studied sample may be considered a risk factor for HIV infection. Crack users have access to information on HIV/ AIDS, but do not make use of it to change risk behaviors that may expose them to HIV infection and dissemination. HIV seroprevalence among crack users (7%) is concerning, which makes it necessary to create preventive strategies for HIV infection and dissemination that are specifically directed toward this population.

Human immunodeficiency virus type 1 and hepatitis C virus co-infection and viral subtypes at an HIV testing center in Brazil

Human immunodeficiency virus (HIV) testing sites have been recognized recently as potential settings for hepatitis C virus (HCV) screening since both viruses share common routes of transmission. HIV and HCV prevalence, predictors, co-infection rates, and viral subtypes were studied in 592 attendants at an anonymous HIV Counseling and Testing Center in central Brazil. Anti-HIV-1 and -HCV antibodies were screened by ELISA, and Western blots were used to confirm HIV infection. Among HIV-seropositive samples, reverse transcriptase-polymerase chain reaction (RT-PCR) and nested-PCR were used to subtype HIV-1 by the Heteroduplex Mobility Analysis (HMA) and HCV by the line probe assay (INNO-LiPA). HIV and HCV seroprevalence was 3.2% (95% CI 2.0-4.9) and 2.5% (95% CI 1.5-4.0), respectively. Intravenous drug use was the risk factor most strongly associated with both HIV and HCV infections, even in a population with few intravenous drug users (n = 6); incarceration was also associated with HCV. HIV/AIDS-positive sexual partner and homosexual/bisexual behaviors were associated independently with HIV-1. The prevalence of HCV infection among HIV-positive persons was 42% (95% CI 20-66), higher than in HIV-negative persons (1.2%; 95% CI 0.5-2.5). HIV-1 subtype B was identified in the env and gag regions of the genome. HCV subtype 3a predominated among co-infected persons and one HCV subtype 1a was detected. Overall, a similar prevalence of HIV and HCV infections and a higher prevalence of HCV among HIV-positive persons were observed. Integrated HIV and HCV screening at HIV testing sites may represent a unique opportunity to provide diagnosis and prevention strategies at a single visit.

[Brazilian psychosocial and operational research vis-à-vis the UNGASS targets]

Items from the UNGASS Draft Declaration of Commitment on HIV/AIDS (2001) are analyzed. The Brazilian experience of new methods for testing and counseling among vulnerable populations, preventive methods controlled by women, prevention, psychosocial support for people living with HIV/AIDS, and mother-child transmission, is discussed. These items were put into operation in the form of keywords, in systematic searches within the standard biomedicine databases, also including the subdivisions of the Web of Science relating to natural and social sciences. The Brazilian experience relating to testing and counseling strategies has been consolidated through the utilization of algorithms aimed at estimating incidence rates and identifying recently infected individuals, testing and counseling for pregnant women, and application of quick tests. The introduction of alternative methods and new technologies for collecting data from vulnerable populations has been allowing speedy monitoring of the epidemic. Psychosocial support assessments for people living with HIV/AIDS have gained impetus in Brazil, probably as a result of increased survival and quality of life among these individuals. Substantial advances in controlling mother-child transmission have been observed. This is one of the most important victories within the field of HIV/AIDS in Brazil, but deficiencies in prenatal care still constitute a challenge. With regard to prevention methods for women, Brazil has only shown a halting response. Widespread implementation of new technologies for data gathering and management depends on investments in infrastructure and professional skills acquisition.

Reconstructing the AIDS epidemic among injection drug users in Brazil

The HIV/AIDS epidemic among injection drug users (IDUs) in Brazil has been unique in terms of temporal and geographical contrasts. This analysis explores these contrasts through the use of multilevel modeling. Standardized AIDS incidence rates among IDUs for Brazilian municipalities (1986-2000) were used as the dependent variable, with a set of social indicators as independent variables (covariates). In some States of the North/Northeast, the epidemic among IDUs has been incipient. The São Paulo epidemic extended to reach a network of municipalities, most of which located far from the capital. More recently, on a smaller scale, a similar extension has been observed in the southernmost States of the country. Both "number of physicians per inhabitant" and "standard distance to the State capital" were found to be associated with AIDS incidence. AIDS cases among IDUs appeared to cluster in wealthier, more developed municipalities. The relative weight of such extensive dissemination in key, heavily populated States prevails in the Brazilian IDU epidemic, defining a central-western-southeastern strip of wealthier middle-sized municipalities and more recently a southern strip of municipalities deeply affected by the epidemic in this population.

A dopamine transporter gene functional variant associated with cocaine abuse in a Brazilian sample

The dopamine (DA) transporter DAT1 is a major target bound by cocaine in brain. We examined the influence of functional genetic variants in DAT1 on cocaine addiction. Repeat polymorphisms, including a 30-bp variable-number tandem repeat (VNTR) in intron 8 (Int8 VNTR) with two common alleles, were genotyped in cocaine-dependent abusers (n = 699) and in controls with no past history of drug abuse (n = 866) from São Paulo, Brazil. Positive association was observed with allele 3 of the Int8 VNTR and cocaine abuse (allele odds ratio = 1.2, 95% confidence interval = 1.01-1.37, P = 0.036; 3/3 homozygote odds ratio = 1.45, 95% confidence interval = 1.18-1.78, P = 0.0008). Population stratification was assessed and did not affect the results. Haplotypic analyses using additional polymorphisms indicated that the Int8 VNTR is responsible for the observed association. Functional analyses in reporter-gene constructs, demonstrated that allele 3 mediates significant (P < 0.05) but small reduced expression compared with the "protective" allele 2. This difference increased when 1 and 10 muM cocaine was added to the cell culture ( approximately 40% reduction of the 3 allele expression versus the 2 allele). The 3 allele also demonstrated approximately 3-fold-increased expression over the 2 allele in response to KCl plus forskolin challenge. We demonstrate a robust association between cocaine dependence and a VNTR allele in SLC6A3, conferring a small but detectable effect, and we show that this VNTR may be functional. This study suggests that DAT1 gene variation may play a role in cocaine dependence etiology.

Concurrent crack and powder cocaine users from Sao Paulo: do they represent a different group?

BACKGROUND

Cocaine abuse is a serious and socially damaging illegal drug problem. Different routes of administration are associated with a specific progression of use, different degrees of abuse liability, propensity for dependence and treatment response. There have been relatively few studies comparing different cocaine users groups and no studies into the characterization of the group of individuals reporting concurrent use of powder cocaine and crack cocaine.

METHODS

Six hundred and ninety-nine cocaine users were assessed during the period August 1997 to October 1998 in one outpatient and six inpatient clinics located in the São Paulo, Brazil. Patients were interviewed using a structured questionnaire schedule in Portuguese, designed specifically for the Brazilian population. The statistical analyses were performed using either ANOVA or a chi-squared test and focusing on their preferred form of use/route of administration and other variables.

RESULTS

For 83% of the variables tested in this study, the Dual Users subgroup (using both powder and crack cocaine) demonstrated statistical differences from the single drug user subgroups. Those differences include the initiation of cocaine, the abuse of other illicit drugs, and rates of criminal history.

CONCLUSION

These data suggest cocaine-dependent individuals who report use of both powder and crack cocaine are an at least partially, distinct subgroup. However, further studies will be necessary to confirm this and to determine if they also show a different treatment response.

Surveillance for HIV-1 incidence using tests for recent infection in resource-constrained countries

Over the past few years, several assays have been developed for the purpose of estimating HIV-1 incidence from cross-sectional population surveys. The tests detect features of the evolving virological or immunological response to HIV-1 infection that distinguish recent from established infection. Surveillance programmes that collect specimens from population surveys for HIV-1 prevalence can apply some of these tests to the same specimen sets to estimate incidence. We describe these tests and discuss the principle and strategy for implementation of a testing programme for recent infection in surveillance settings. Test-specific prerequisites, such as calibration, validation, and quality assurance, and other test-specific performance characteristics that may influence interpretation, epidemiological considerations that may guide application, and practical operational considerations for implementation in surveillance settings are considered. When properly and judiciously applied, the capacity to estimate incidence from existing programmes that conduct surveillance for prevalent HIV-1 infection will enhance the capacity for more precise and timely analysis of the dynamics of the epidemic and the effectiveness of public health interventions.

The role of "long-term" and "new" injectors in a declining HIV/AIDS epidemic in Rio de Janeiro, Brazil

BACKGROUND

A substantial decline of HIV prevalence has been observed in injection drug users (IDUs) from Rio de Janeiro, in recent years. Differential characteristics and behaviors of new (injecting for <6 years) and long-term (>=6y) injectors may help to understand recent changes and to implement appropriate prevention strategies.

METHODS

Between October 1999 and December 2001, 609 active/ex-IDUs were recruited from different communities, interviewed, and tested for HIV. Contingency table analysis and t-tests were used to assess differences between new and long-term injectors. Multiple logistic regression was used to identify independent predictors of HIV serostatus for long-term and new injectors.

RESULTS

HIV prevalence was 11.7% for 309 long-term injectors (95% CI 8.1-15.3) and 4.3% for 300 new injectors (95% CI 2.0-6.6). New injectors reported having engaged in treatment and having received syringes from needle exchange programs (NEPs) more frequently than long-term injectors in the last 6 months, but sharing behaviors remained frequent and even increased vis-à-vis long-term injectors. For male new injectors, "sexual intercourse with another man" was found to be the sole significant risk factor for HIV infection (Adj OR = 8.03; 95% CI 1.52-42.48). Among male long-term injectors, "to have ever injected with anyone infected with HIV" (Adj OR = 3.91; 95% CI 1.09-14.06) and to have "ever been in prison" (Adj OR = 2.56; 95% CI 1.05-6.24) were found to be significantly associated with HIV infection.

DISCUSSION

New injectors are seeking help in drug treatment centers or needle exchange programs. They differ from long-term injectors in terms of their risk factors for HIV infection and have lower prevalence levels for HIV. Such differences may help to understand the recent dynamics of HIV/AIDS in this population and highlight the need to reinforce new injectors' help-seeking behavior and to reduce current unacceptably high levels of unprotected sex and syringe sharing in new injectors despite attendance of prevention/treatment programs.

HIV-1 infection among injection and ex-injection drug users from Rio de Janeiro, Brazil: prevalence, estimated incidence and genetic diversity

BACKGROUND AND OBJECTIVES

Due to their behavioral conditions and vulnerability, injection drug users (IDUs) are prone to multiple simultaneous or sequential infections with distinct HIV-1 subtypes and variants, making them a key population for molecular epidemiology surveillance. In the present study, we evaluated HIV-1 infection seroprevalence, genetic diversity and estimated incidence among IDUs and ex-injection drug users (ex-IDUs) from Rio de Janeiro, Brazil.

STUDY DESIGN

Six hundred and eight IDUs and ex-IDUs, recruited between 1999 and 2001, were interviewed and agreed to donate 30 ml of blood. The serologic status for HIV infection was determined by two ELISAs and confirmed by IFA. CD4+ T-cell percentages were assessed by flow cytometry. HIV-1 positive samples were submitted to viral load quantification. DNA samples were PCR amplified and HIV-1 subtypes were determined using env and gag HMA.

RESULTS AND CONCLUSIONS

Forty-eight (7.89%) individuals were seropositive for HIV-1 infection. The seroincidence of HIV-1 infection was estimated as 0.76%. HIV-1 env and gag subtyping identified 29 (69%) samples as belonging to subtype B, 7 (16.7%) to subtype F, and 6 (14.3%) discordant env/gag genomes infections, indicating the circulation of recombinant viruses in this population.

Epidemiologic and molecular characterization of human immunodeficiency virus type 1 in southern Brazil

HIV subtype C is the most prevalent subtype in the world. Despite its recent expansion in Brazil, HIV-1C already prevails in the southernmost state of Brazil, Rio Grande do Sul. This unique HIV epidemiology has prompted us to characterize that population. Seventy-seven HIV-1-infected subjects attending the largest HIV/AIDS clinic of the state had the protease and reverse transcriptase (RT) genes of their virus subtyped and genotyped. When subtype-specific infections were plotted according to year of diagnosis, the prevalence of subtype C was shown to increase over the last 18 years of the epidemic, along with a concomitant decrease of subtype B. Comparison of subtype C-infected treated and untreated subjects revealed amino acid differences in protease and RT, especially in the RT mutation D/G123S. The overall analysis of drug resistance mutations in viruses from treated subjects has highlighted some associations between subtypes and particular mutations, such as V82A/F/T/S in protease and subtype F1 and M41L and L210W in RT and subtype B. The characterization of this important population, which is one of a few in the developing world where a large number of HIV-1C-infected subjects are under antiretroviral treatment, underscores its potential usefulness in clinical, treatment, and vaccine trials in Brazil.

Risk factors for incident HIV infection among anonymous HIV testing site clients in Santos, Brazil: 1996-1999

OBJECTIVES

To determine temporal trends in HIV infection and risk factors among persons seeking anonymous HIV testing in Santos, Brazil.

METHODS

Data and sera from persons testing for HIV from 1996 to 1999 were used. Exposures were abstracted from HIV testing risk assessments. Stored HIV-positive sera were tested to identify recently acquired HIV infection using a serologic testing algorithm for detecting recent HIV seroconversion (STARHS). Independent associations between exposures and recently acquired HIV infection were determined using multivariate analyses.

RESULTS

Overall, estimated HIV incidence was 2.0% (95% CI: 1.1-3.5) for the 4-year period: 1.2% (95% CI: 0.5-2.6) in women and 2.7% (95% CI: 1.3-5.0) in men. Incidence increased among women but remained stable among men. Exposures independently associated with incident infection included a history of sex work (OR= 5.4, 95% CI: 1.5-18.7), concurrent syphilis infection (OR =4.1, 95% CI: 1.4-11.9), anal sex (OR = 3.0, 95% CI: 1.3-7.1), and having an HIV-positive sexual partner (OR= 1.4, 95% CI: 1.1-1.9).

CONCLUSIONS

This study further demonstrates the public health utility of using the STARHS for the assessment of emerging trends in the HIV epidemic. Results from this study will help to target appropriate prevention strategies directed toward at-risk populations in Santos.