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

Incidence of HIV and hepatitis C virus among people who inject drugs, and associations with age and sex or gender: a global systematic review and meta-analysis

BACKGROUND

Measuring the incidence of HIV and hepatitis C virus (HCV) infection among people who inject drugs (PWID) is key to track progress towards elimination. We aimed to summarise global data on HIV and primary HCV incidence among PWID and associations with age and sex or gender.

METHODS

In this systematic review and meta-analysis, we updated an existing database of HIV and HCV incidence studies among PWID by searching MEDLINE, Embase, and PsycINFO, capturing studies published between Jan 1, 2000, and Dec 12, 2022, with no language or study design restrictions. We contacted authors of identified studies for unpublished or updated data. We included studies that estimated incidence by longitudinally re-testing people at risk of infection or by using assays for recent infection. We pooled incidence and relative risk (RR; young [generally defined as ≤25 years] vs older PWID; women vs men) estimates using random-effects meta-analysis and assessed risk of bias with a modified Newcastle-Ottawa scale. This study is registered with PROSPERO, CRD42020220884.

FINDINGS

Our updated search identified 9493 publications, of which 211 were eligible for full-text review. An additional 377 full-text records from our existing database and five records identified through cross-referencing were assessed. Including 28 unpublished records, 125 records met the inclusion criteria. We identified 64 estimates of HIV incidence (30 from high-income countries [HICs] and 34 from low-income or middle-income countries [LMICs]) and 66 estimates of HCV incidence (52 from HICs and 14 from LMICs). 41 (64%) of 64 HIV and 42 (64%) of 66 HCV estimates were from single cities rather than being multi-city or nationwide. Estimates were measured over 1987-2021 for HIV and 1992-2021 for HCV. Pooled HIV incidence was 1·7 per 100 person-years (95% CI 1·3-2·3; I2=98·4%) and pooled HCV incidence was 12·1 per 100 person-years (10·0-14·6; I2=97·2%). Young PWID had a greater risk of HIV (RR 1·5, 95% CI 1·2-1·8; I2=66·9%) and HCV (1·5, 1·3-1·8; I2=70·6%) acquisition than older PWID. Women had a greater risk of HIV (RR 1·4, 95% CI 1·1-1·6; I2=55·3%) and HCV (1·2, 1·1-1·3; I2=43·3%) acquisition than men. For both HIV and HCV, the median risk-of-bias score was 6 (IQR 6-7), indicating moderate risk.

INTERPRETATION

Although sparse, available HIV and HCV incidence estimates offer insights into global levels of HIV and HCV transmission among PWID. Intensified efforts are needed to keep track of the HIV and HCV epidemics among PWID and to expand access to age-appropriate and gender-appropriate prevention services that serve young PWID and women who inject drugs.

FUNDING

Canadian Institutes of Health Research, Fonds de recherche du Québec-Santé, Canadian Network on Hepatitis C, UK National Institute for Health and Care Research, and WHO.

Potential overestimation of HIV-1 sub-subtype F1 circulation in Rio de Janeiro, Brazil

In Brazil, detection of the HIV-1 sub-subtype F1 has decreased with a simultaneous increase in detection of the recombinant FB and FC forms. In previous HIV-1 env molecular epidemiology studies in Rio de Janeiro, 11.4% of the detected sequences were of the F1 sub-subtype. With the goal of re-estimating the prevalence of the HIV-1 F1 sub-subtype, we performed extended analyses of these samples by examining five genomic regions, resulting in 3.3% being confirmed as F1. Moreover, genomic analysis of 11 of the 21 samples identified as F1 confirmed that nine were F1 and two were BF1. Considering the number of samples assayed, the prevalence of F1 was quite low, which supports the use of different genomic regions for the assessment of HIV-1 classification in countries where several subtypes and recombinant forms co-circulate.

HIV-1 epidemiology and circulating subtypes in the countryside of South Brazil

INTRODUCTION

Human immunodeficiency virus type 1 (HIV-1) has spread worldwide, with several subtypes and circulating recombinant forms. Brazil has an incidence of 20.5 HIV-1/acquired immunodeficiency syndrome (AIDS) patients per 100,000 inhabitants; however, the Southernmost State of Rio Grande do Sul (RS) has more than twice the number of HIV-1-infected people (41.3/100,000 inhabitants) and a different pattern of subtype frequencies, as previously reported in studies conducted in the capital (Porto Alegre) and its metropolitan region. This study examined HIV-1/AIDS epidemiological and molecular aspects in the countryside of Rio Grande do Sul.

METHODS

Socio-demographic, clinical and risk behavioral characteristics were obtained from HIV-1-positive adult patients using a structured questionnaire. HIV-1 subtypes were determined by nested-polymerase chain reaction (PCR) and sequencing of the pol and env genes.

RESULTS

The study sample included 149 (55% women) patients with a mean age of 41.8 ± 11.9 years. Most (73.8%) patients had a low education level and reported heterosexual practices as the most (91.9%) probable transmission route. HIV-1 subtypes were detected in 26 patients: 18 (69.2%) infected with subtype C, six (23.1%) infected with subtype B and two (7.7%) infected with BC recombinant forms.

CONCLUSIONS

These data highlight the increasing number of HIV-1 subtype C infections in the countryside of South Brazil.

Short Communication: Reassessing the Origin of the HIV-1 CRF02_AG Lineages Circulating in Brazil

HIV-1 CRF02_AG is responsible for at least 8% of the HIV-1 infections worldwide and is distributed mainly in West Africa. CRF02_AG has recently been reported in countries where it is not native, including Brazil. In a previous study including 10 CRF02_AG Brazilian samples, we found at least four independent introductions and two autochthonous transmission networks of this clade in Brazil. As more CRF02_AG samples have been identified in Brazil, we performed a new phylogeographic analysis using a larger dataset than before. A total of 20 Brazilian (18 from Rio de Janeiro and two from São Paulo) and 1,485 African HIV-1 CRF02_AG pol sequences were analyzed using maximum likelihood (ML). The ML tree showed that the Brazilian sequences were distributed in five different lineages. The Bayesian phylogeographic analysis of the Brazilian and their most closely related African sequences (n = 212) placed the origin of all Brazilian lineages in West Africa, probably Ghana, Senegal, and Nigeria. Two monophyletic clades were identified, comprising only sequences from Rio de Janeiro, and their date of origin was estimated at around 1985 (95% highest posterior density: 1979-1992). These results support the existence of at least five independent introductions of the CRF02_AG lineage from West Africa into Brazil and further indicate that at least two of these lineages have been locally disseminated in the Rio de Janeiro state over the past 30 years.

Assessing the HIV-1 Epidemic in Brazilian Drug Users: A Molecular Epidemiology Approach

Person who inject illicit substances have an important role in HIV-1 blood and sexual transmission and together with person who uses heavy non-injecting drugs may have less than optimal adherence to anti-retroviral treatment and eventually could transmit resistant HIV variants. Unfortunately, molecular biology data on such key population remain fragmentary in most low and middle-income countries. The aim of the present study was to assess HIV infection rates, evaluate HIV-1 genetic diversity, drug resistance, and to identify HIV transmission clusters in heavy drug users (DUs). For this purpose, DUs were recruited in the context of a Respondent-Driven Sampling (RDS) study in different Brazilian cities during 2009. Overall, 2,812 individuals were tested for HIV, and 168 (6%) of them were positive, of which 19 (11.3%) were classified as recent seroconverters, corresponding to an estimated incidence rate of 1.58%/year (95% CI 0.92–2.43%). Neighbor joining phylogenetic trees from env and pol regions and bootscan analyses were employed to subtype the virus from132 HIV-1-infected individuals. HIV-1 subtype B was prevalent in most of the cities under analysis, followed by BF recombinants (9%-35%). HIV-1 subtype C was the most prevalent in Curitiba (46%) and Itajaí (86%) and was also detected in Brasília (9%) and Campo Grande (20%). Pure HIV-1F infections were detected in Rio de Janeiro (9%), Recife (6%), Salvador (6%) and Brasília (9%). Clusters of HIV transmission were assessed by Maximum likelihood analyses and were cross-compared with the RDS network structure. Drug resistance mutations were verified in 12.2% of DUs. Our findings reinforce the importance of the permanent HIV-1 surveillance in distinct Brazilian cities due to viral resistance and increasing subtype heterogeneity all over Brazil, with relevant implications in terms of treatment monitoring, prophylaxis and vaccine development.

Molecular epidemiology of HIV-1 in Panama: origin of non-B subtypes in samples collected from 2007 to 2013

Phylogenetic studies have suggested that the HIV-1 epidemic in the Americas is mainly dominated by HIV subtype B. However, countries of South America and the Caribbean have recently reported changes in their circulating HIV-1 genetic profiles. The aim of this study was to characterize the molecular profile of the HIV-1 epidemic in Panama by the analysis of 655 polymerase gene (pol) sequences that were obtained from HIV-infected Panamanians diagnosed between 1987 and 2013. Blood samples were collected from recently infected, antiretroviral drug-naïve and treatment-experienced subjects since mid-2007 to 2013. Viral RNA from plasma was extracted and sequences of HIV protease and reverse transcriptase genes were obtained. Bootscanning and phylogenetic methods were used for HIV subtyping and to trace the putative origin of non-B subtype strains. Our results showed that HIV-1 infections in Panama are dominated by subtype B (98.9%). The remaining 1.1% is represented by a diverse collection of recombinant variants including: three URFs_BC, one CRF20_BG, and one CRF28/29_BF, in addition to one subtype F1 and one subtype C, none of which were previously reported in Panama. The non-B subtype variants detected in Panama were probably introduced from Brazil (subtype F1 and CRF28/29_BF), Cuba (CRF20_BG), Dominican Republic (URFs_BC) and India (subtype C). Panama is the geographical vertex that connects the North with South America and the Caribbean through trade and cultural relations, which may explain the observed introductions of non-B subtype HIV-1 variants from both the Caribbean and South America into this Central American country.

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.

Testing a subtype-specific gp41 amplification method for genotyping individuals infected by human immunodeficiency virus type-1 in the Brazilian population of Itajaí, South Brazil

The method used by YAGYU et al. for the subtype-specific polymerase chain reaction (PCR) amplification of the gp41 transmembrane region of the human immunodeficiency virus type-1 (HIV-1) env gene, was tested. HIV-1 proviral DNA from 100 infected individuals in Itajaí, South Brazil was used to analyze this method. Seventy individuals were determined according to this method as having PCR products at the expected size for subtypes B, C, D and F. Of these individuals, 26 (37.1%) were observed as having the expected amplification for subtype C, and 42 (60%) were observed as having the expected products for subtypes B and D. Of the subtype B and D amplicons, 16 (22.9%) were classified as subtype D, and 26 (37.1%) were classified as subtype B. Two individuals (2.9%) had amplicons that were observed after subtype F-specific amplification was performed. Sequencing and comparing the patient sequences to reference sequences confirmed the classification of sequences of subtypes C and B. However, sequences that were falsely determined as being D and F in the PCR assay were determined as being subtypes C and B, respectively, by sequence analysis. For those individuals from whom no amplified products were obtained, a low viral load that was indicated in their patient history may explain the difficulty in subtyping by PCR methods. This issue was demonstrated by the results of ANOVA when testing the effect of viral load on the success of PCR amplification. The alignment of the obtained sequences with HIV-1 reference sequences demonstrated that there is high intra-subtype diversity. This indicates that the subtype-specific primer binding sites were not conserved or representative of the subtypes that are observed in the Brazilian populations, and that they did not allow the correct classification of HIV-1 subtypes. Therefore, the proposed method by YAGYU et al. is not applicable for the classification of Brazilian HIV-1 subtypes.

Inferring viral population structures using heteroduplex mobility and DNA sequence analyses

Heteroduplex mobility (HMA) and tracking assays (HTA) are used to assess genetic relationships between DNA molecules. While distinguishing relationships between clonal or nearly clonal molecules is relatively straightforward, inferring population structures is more complex. To address this issue, HIV-1 quasispecies with varying levels of diversity were studied using both HTA and DNA sequencing. Viral diversity estimates and the temporal features of virus evolution were found to be generally concordant between HTA and DNA sequencing. In addition, the distribution of pairwise differences and the rates of virus divergence were similar between the two methods. These findings support the use of HTA to characterize variant populations of DNA and strengthen previous inferences concerning the evolution of HIV-1 over the course of infection.

The increasing prevalence of HIV-1 subtype C in Southern Brazil and its dispersion through the continent

The HIV-1 has evolved swiftly and the scenario of HIV-1 genetic diversity is constantly changing. In South America, recombinant forms of subtypes B, F1, and BF1 have historically driven the HIV-1 epidemic. In recent years, however, infection with subtype C has gained prominence as its prevalence increased in Southern Brazil as well as neighboring countries. Current studies point to a single introduction of closely related strains as the beginning of the Brazilian subtype C epidemic. However, the place of origin of these strains, date, and route of introduction are under continuous debate as well as the clinical outcomes of the emergence of subtype C. Therefore, this paper reviews the history of the HIV-1 subtype C in Brazil, particularly in the Southern region, covering its demographic and evolutionary history and the possible implications to the Brazilian AIDS epidemic as well as to neighboring countries.

Are females who inject drugs at higher risk for HIV infection than males who inject drugs: an international systematic review of high seroprevalence areas

OBJECTIVE

There are multiple reasons why females who inject drugs may be more likely to become infected with HIV than males who inject drugs. Where this is the case, special HIV prevention programs for females would be needed.

DESIGN

International systematic review and meta-analysis of studies across 14 countries.

METHODS

Countries with high seroprevalence (>20%) HIV epidemics among persons who inject drugs (PWID) were identified from the Reference Group to the UN on HIV and Injecting Drug Use. Systematic literature reviews collected data on HIV prevalence by gender for these countries. Non-parametric and parametric tests along with meta-analytic techniques examined heterogeneity and differences in odds ratios (OR) across studies.

RESULTS

Data were abstracted from 117 studies in 14 countries; total sample size N = 128,745. The mean weighted OR for HIV prevalence among females to males was 1.18 [95% CI 1.10-1.26], with high heterogeneity among studies (I(2)= 70.7%). There was a Gaussian distribution of the log ORs across studies in the sample.

CONCLUSION

There was a significantly higher HIV prevalence among females compared to males who inject drugs in high seroprevalence settings, but the effect size is extremely modest. The high level of heterogeneity and the Gaussian distribution suggest multiple causes of differences in HIV prevalence between females and males, with a specific difference determined by local factors. Greater understanding of factors that may protect females from HIV infection may provide insights into more effective HIV prevention for both females and males who inject drugs.

Phylodynamics of HIV-1 subtype F1 in Angola, Brazil and Romania

The HIV-1 subtype F1 is exceptionally prevalent in Angola, Brazil and Romania. The epidemiological context in which the spread of HIV occurred was highly variable from one country to another, mainly due to the existence of a long-term civil war in Angola and the contamination of a large number of children in Romania. Here we apply phylogenetic and Bayesian coalescent-based methods to reconstruct the phylodynamic patterns of HIV-1 subtype F1 in such different epidemiological settings. The phylogenetic analyses of HIV-1 subtype F1 pol sequences sampled worldwide confirmed that most sequences from Angola, Brazil and Romania segregated in country-specific monophyletic groups, while most subtype F1 sequences from Romanian children branched as a monophyletic sub-cluster (Romania-CH) nested within sequences from adults. The inferred time of the most recent common ancestor of the different subtype F1 clades were as follow: Angola=1983 (1978-1989), Brazil=1977 (1972-1981), Romania adults=1980 (1973-1987), and Romania-CH=1985 (1978-1989). All subtype F1 clades showed a demographic history best explained by a model of logistic population growth. Although the expansion phase of subtype F1 epidemic in Angola (mid 1980s to early 2000s) overlaps with the civil war period (1975-2002), the mean estimated growth rate of the Angolan F1 clade (0.49 year(-1)) was not exceptionally high, but quite similar to that estimated for the Brazilian (0.69 year(-1)) and Romanian adult (0.36 year(-1)) subtype F1 clades. The Romania-CH subtype F1 lineage, by contrast, displayed a short and explosive dissemination phase, with a median growth rate (2.47 year(-1)) much higher than that estimated for adult populations. This result supports the idea that the AIDS epidemic that affected the Romanian children was mainly caused by the spread of the HIV through highly efficient parenteral transmission networks, unlike adult populations where HIV is predominantly transmitted through sexual route.

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.

Comparative reactivity of serum samples from Argentinean HIV-infected patients with V3 peptides from subtype B or BF recombinants

To analyze humoral cross-reactivity to V3 peptides from subtype B and BF recombinant forms, plasma samples from 50 HIV-1-infected patients were characterized by sequencing fragments of the env and pol genes. An in-house EIA was performed using peptides corresponding to the 15 central amino acids of the V3 loop of gp120 from subtypes B (MN, SF2) and F1 and a consensus peptide from Argentinean BF recombinants. No differences were found with respect to the infecting subtype, but significant differences were found among the peptides. Reactivity was higher against the MN and BF peptides in both groups infected with subtype B (n = 28) and BF (n = 22) recombinants than against subtype F1 and SF2 peptides.

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.

Phylodynamics of HIV-1 circulating recombinant forms 12_BF and 38_BF in Argentina and Uruguay

Background

Although HIV-1 CRF12_BF and CRF38_BF are two epidemiologically important recombinant lineages circulating in Argentina and Uruguay, little is known about their population dynamics.

Methods

A total of 120 "CRF12_BF-like" and 20 "CRF38_BF-like" pol recombinant sequences collected in Argentina and Uruguay from 1997 to 2009 were subjected to phylogenetic and Bayesian coalescent-based analyses to estimate evolutionary and demographic parameters.

Results

Phylogenetic analyses revealed that CRF12_BF viruses from Argentina and Uruguay constitute a single epidemic with multiple genetic exchanges among countries; whereas circulation of the CRF38_BF seems to be confined to Uruguay. The mean estimated substitution rate of CRF12_BF at pol gene (2.5 × 10-3 substitutions/site/year) was similar to that previously described for subtype B. According to our estimates, CRF12_BF and CRF38_BF originated at 1983 (1978-1988) and 1986 (1981-1990), respectively. After their emergence, the CRF12_BF and CRF38_BF epidemics seem to have experienced a period of rapid expansion with initial growth rates of around 1.2 year^-1 and 0.9 year^-1, respectively. Later, the rate of spread of these CRFs_BF seems to have slowed down since the mid-1990s.

Conclusions

Our results suggest that CRF12_BF and CRF38_BF viruses were generated during the 1980s, shortly after the estimated introduction of subtype F1 in South America (~1975-1980). After an initial phase of fast exponential expansion, the rate of spread of both CRFs_BF epidemics seems to have slowed down, thereby following a demographic pattern that resembles those previously reported for the HIV-1 epidemics in Brazil, USA, and Western Europe.

Close phylogenetic relationship between Angolan and Romanian HIV-1 subtype F1 isolates

BACKGROUND

Here, we investigated the phylogenetic relationships of the HIV-1 subtype F1 circulating in Angola with subtype F1 strains sampled worldwide and reconstructed the evolutionary history of this subtype in Central Africa.

METHODS

Forty-six HIV-1-positive samples were collected in Angola in 2006 and subtyped at the env-gp41 region. Partial env-gp120 and pol-RT sequences and near full-length genomes from those env-gp41 subtype F1 samples were further generated. Phylogenetic analyses of partial and full-length subtype F1 strains isolated worldwide were carried out. The onset date of the subtype F1 epidemic in Central Africa was estimated using a Bayesian Markov chain Monte Carlo approach.

RESULTS

Nine Angolan samples were classified as subtype F1 based on the analysis of the env-gp41 region. All nine Angolan sequences were also classified as subtype F1 in both env-gp120 and pol-RT genomic regions, and near full-length genome analysis of four of these samples confirmed their classification as "pure" subtype F1. Phylogenetic analyses of subtype F1 strains isolated worldwide revealed that isolates from the Democratic Republic of Congo (DRC) were the earliest branching lineages within the subtype F1 phylogeny. Most strains from Angola segregated in a monophyletic group together with Romanian sequences; whereas South American F1 sequences emerged as an independent cluster. The origin of the subtype F1 epidemic in Central African was estimated at 1958 (1934-1971).

CONCLUSION

"Pure" subtype F1 strains are common in Angola and seem to be the result of a single founder event. Subtype F1 sequences from Angola are closely related to those described in Romania, and only distantly related to the subtype F1 lineage circulating in South America. Original diversification of subtype F1 probably occurred within the DRC around the late 1950s.

Distribution of CCR5 genotypes and HLA Class I B alleles in HIV-1 infected and uninfected injecting drug users from Rio de Janeiro, Brazil

Host genetic factors play an important role in the HIV epidemic dynamics, and have been considered in studies assessing susceptibility/resistance to HIV-1 infection as well as clinical evolution. Class I and Class II HLA alleles have been associated with the heterogeneity of HIV-1 infection susceptibility, as protective or risk factors for HIV-1 transmission. Moreover, a 32-base pair deletion in the HIV-1 CCR5 gene-coding region confers resistance to HIV-1 infection in homozygous individuals for the deleted allele. In this study, DNA samples from HIV-1 infected and uninfected injecting drug users (IDUs) from Rio de Janeiro were PCR amplified to determine CCR5 genotypes based on the presence of the CCR5Delta32 mutation and typed for the HLA-B locus, in an attempt to assess possible associations between these genetic factors and susceptibility/resistance to HIV-1 infection. The distribution of CCR5 genotypes between the two IDU groups did not differ. The homozygous mutant genotype Delta32/Delta32 was not found in this study. Except for HLA-B*45 (4.0% vs. 3.0%; p=0.04) and for B*51 (12.1% vs. 4.4%; p=0.002), no statistically significant differences were made evident when analyzing the frequencies of each HLA-B allele between Caucasian and non-Caucasian IDUs. The most frequent HLA-B alleles were B*15; B*35; B*44 and B*51. Although some differences in the allele frequencies could be observed between the two IDU groups, none of these was statistically significant. Therefore, no putative association between these genetic markers and susceptibility/resistance to HIV-1 infection could be made evident in the present study. So far, the assessment of genetic markers among the IDU population has been restricted to North American, European, and Asian studies and this report represents a pioneer descriptive study of the distribution of CCR5 genotypes and HLA-B alleles in Rio de Janeiro, Brazil.

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.

HIV type 1 subtype C and CB Pol recombinants prevail at the cities with the highest AIDS prevalence rate in Brazil

HIV-1 B is predominant in Brazil, but HIV-1 C has increasingly been reported in the south of the country. However, many samples clustering with clade C are actually a recombinant, with a small B segment at RT (CRF31). Samples (209) from the three cities with the highest aids prevalence rate are analyzed. Partial polymerase sequences from HIV RNA made it possible to determine HIV clades and recombination patterns and to identify primary drug resistance mutations (DRMs). The incidence was estimated with a BED assay. HIV-1 C and CRF31 patterns were twice as frequent as clade B at all sites, but the proportion of C and CRF31 patterns was significantly different among sites. The incidence estimate for SC was 2.6 persons-years. Infection in recent or younger cases showed no association with clade C. Surveillance DRM was observed in 8.3% (95% CI 5-13), mostly to NNRTIs. Clade F pol genomes had significantly more primary DRM.

Treatment at scale in Brazil: a physician's perspective

In 1996, Brazil became the first developing country to provide universal access to antiretroviral therapy (ART), based on a strategy that utilizes an individualized approach to treatment and an open formulary. At the time, the number of patients in need of treatment was less than 15% of what it is today, there were six approved drugs for the treatment of HIV infection (compared with 25 today), and the life expectancy of patients was measured in months and years, not in decades. In recent years, preventable and treatable conditions such as cardiovascular diseases increased significantly faster as causes of death among HIV-infected individuals than in the general population. In the near future there will be a substantial increase in the number of patients in need of therapy and in the number of patients using more complex regimens who also have co-morbidities that impact prognosis. Brazil will thus need to expand its network of treatment facilities, increase its capacity to manage more complex clinical conditions, and decide on the proper balance of sophistication that will be required. As the Brazilian scientific output is not commensurate with its successes in the treatment and prevention of HIV infection, there is little empirical basis to inform decisions on how best to allocate finite resources. The Brazilian response to the HIV/AIDS epidemic, universal access to ART in particular, is an example to other developing countries. The Brazilian experience also shows that operational research should be an integral part of programmes of access to treatment, if their long-term sustainability is to be ensured.

Trends in drug resistance mutations in antiretroviral-naïve intravenous drug users of Rio de Janeiro

DNA sequencing of a pol gene fragment from drug-naive injecting drug users samples obtained at two time points of the Brazilian AIDS epidemic (Pre-HAART era: 1994 to early 1997, n = 27; post-HAART era: 1999-2001, n = 38) was undertaken to assess HIV-1 antiretroviral drug resistance mutations and subtyping profiles. Genotypic analysis revealed the presence of PR primary L90M, D30N, M46I, and V82A mutations in 7.9% of the post-HAART group, and a high frequency of secondary mutations (84.2%). Nucleoside RT-associated mutations were observed in 13.2%. In the pre-HAART group, a higher frequency of RT mutations was observed (22.2%) and no PR primary mutations were found, in agreement with the introduction of protease inhibitors (PIs) in therapy during the same period. The identification of 7.9% of drug-naive injecting drug users already bearing RT/PR primary resistance mutations in the post-HAART era group constitutes a major concern in terms of dissemination of drug resistant viruses. The resistance mutations profile of the individuals may reflect the context of antiretroviral treatment in Brazil at the sample collection periods (1994-1997 and 1999-2001). In spite of the differences observed in the drug resistance profiles, similar frequencies of subtype B (63.0 vs. 73.7%), F (22.2 vs. 10.5%), and recombinant B/F (14.8 vs. 15.8%) viruses were found, respectively, in the pre- and post-HAART groups.

[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.

"The first shot": the context of first injection of illicit drugs, ongoing injecting practices, and hepatitis C infection in Rio de Janeiro, Brazil

The context of first drug injection and its association with ongoing injecting practices and HCV (hepatitis C virus) infection were investigated. Injection drug users (IDUs) (N = 606) were recruited in "drug scenes" (public places, bars) in Rio de Janeiro, Brazil, interviewed, and tested for HCV. Sharing of needles/syringes was more prevalent at the first injection (51.3%) than at the baseline interview (36.8%). Those who shared syringes/needles at first injection were more likely to be currently engaged in direct/indirect sharing practices. Among young injectors (< 30 years), those reporting sharing of needles/ syringes at the first injection were about four times more likely to have been infected by HCV. Hepatitis C virus prevalence among active IDUs (n = 272) was 11%. Prison history and longer duration of drug injection were identified as independent predictors of HCV infection. To effectively curb HCV transmission among IDUs and minimize harms associated with risk behaviors, preventive strategies should target individuals initiating drug injection beginning with their very first injection and discourage the transition from non-injecting use to the self-injection of illicit drugs.

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.

Is human immunodeficiency virus/acquired immunodeficiency syndrome decreasing among Brazilian injection drug users? Recent findings and how to interpret them

We briefly review findings from Brazilian settings where the human immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS) epidemic among injection drug users (IDUs) seems to be decreasing, highlighting recent findings from Rio de Janeiro and discussing methodological alternatives. Former analyses using serologic testing algorithm for recent HIV seroconversion have shown that HIV incidence has been low in IDUs recruited by two different surveys carried out in Rio, where low injection frequencies and infection rates have been found among new injectors. The proportion of AIDS cases among IDUs in Rio has been fairly modest, compared to São Paulo and especially to the southernmost states. Notwithstanding, the interpretation of findings from serial surveys constitutes a challenge, magnified in the assessment of HIV spread among IDUs due to the dynamic nature of the drug scenes and limitations of sampling strategies targeting hard-to-reach populations. Assessment of epidemic trends may profit from the triangulation of data, but cannot avert biases associated with sampling errors. Efforts should be made to triangulate data from different sources, besides exploring specific studies from different perspectives. In an attempt to further assess the observed trends, we carried out original analyses using data from Brazilian AIDS databank.