Syphilis and Co-Infections with HIV-1, HBV, and HCV among People Who Use Crack-Cocaine in Northern Brazil

The rates of syphilis and viral co-infections among people who use crack-cocaine (PWUCC) were assessed in this study. This cross-sectional study relied on biological and self-reported socio-behavioral data from a convenience sample of 990 PWUCC from twenty-six municipalities in the states of Amapá and Pará, northern Brazil. Blood samples were collected to assess the presence of Treponema pallidum using the Rapid Qualitative Test (RQT) and the Venereal Disease Research Laboratory (VDRL). Reactive samples by RQT were used to assess the presence of HBV, HCV, and HIV-1 using Enzyme Immunoassay (EIA) and Polymerase Chain Reaction (PCR). Logistic regression models were used to determine the association of variables assessed with syphilis. In total, 287 (29.0%) of the PWUCC sample had reactive results for syphilis. HBV (15.7%), HCV (5.9%), and HIV-1 (9.8%) were detected among PWUCC with syphilis. Young age, low monthly income and education level, long duration of crack-cocaine use, condomless sex, multiple sex partners, and exchange of sex for money/drugs were associated with syphilis. The present study provides unique insights on the epidemiological status of syphilis among PWUCC in northern Brazil, with multiple implications for improving urgent interventions for diagnosis, prevention, and treatment.

Detection and Genetic Characterization of Hepatitis B and D Viruses: A Multi-Site Cross-Sectional Study of People Who Use Illicit Drugs in the Amazon Region

Hepatitis B (HBV) and delta (HDV) viruses are endemic in the Amazon region, but vaccine coverage against HBV is still limited. People who use illicit drugs (PWUDs) represent a high-risk group due to common risk behavior and socioeconomic factors that facilitate the acquisition and transmission of pathogens. The present study assessed the presence of HBV and HBV-HDV co-infection, identified viral sub-genotypes, and verified the occurrence of mutations in coding regions for HBsAg and part of the polymerase in HBV-infected PWUDs in municipalities of the Brazilian states of Amapá and Pará, in the Amazon region. In total, 1074 PWUDs provided blood samples and personal data in 30 municipalities of the Brazilian Amazon. HBV and HDV were detected by enzyme-linked immunosorbent assay and polymerase chain reaction. Viral genotypes were identified by nucleotide sequencing followed by phylogenetic analysis, whereas viral mutations were analyzed by specialized software. High rates of serological (32.2%) and molecular (7.2%) markers for HBV were detected, including cases of occult HBV infection (2.5%). Sub-genotypes A1, A2, D4, and F2a were most frequently found. Escape mutations due to vaccine and antiviral resistance were identified. Among PWUDs with HBV DNA, serological (19.5%) and molecular (11.7%) HDV markers were detected, such as HDV genotypes 1 and 3. These are worrying findings, presenting clear implications for urgent prevention and treatment needs for the carriers of these viruses.

Treponema pallidum in female sex workers from the Brazilian Marajó Archipelago: prevalence, risk factors, drug-resistant mutations and coinfections

BACKGROUND

Female sex workers (FSWs) are an especially vulnerable group for syphilis and other sexually transmitted infection (STIs). This study determined the prevalence of syphilis in FSWs and factors associated with this disease in the Marajó Archipelago (northern Brazil), as well as the frequency of point mutations (A2058G and A2059G) in the 23S rRNA gene of Treponema pallidum and coinfections with hepatitis B virus (HBV), hepatitis C virus (HCV) and hepatitis D virus (HDV).

METHODS

FSWs were diagnosed using a rapid qualitative test and the isolates were evaluated for the presence of point mutations by real-time PCR. Blood samples with T. pallidum were tested for the presence of HBV, HCV and HDV by ELISA and confirmed by real-time PCR. The factors associated with syphilis were identified using Poisson regression models.

RESULTS

Overall, 41.1% FSWs tested positive for syphilis and 23.5% were infected with strains having A2058G/A2059G point mutations. HBV (23.0%) and HCV (8.1%) were detected among FSWs with syphilis. Six factors were associated with syphilis: low levels of education, reduced income, drug use, unprotected sex, a lengthy career in prostitution and a lack of regular medical check-ups.

CONCLUSIONS

These findings indicate an urgent need for implementation of effective strategies to diagnose, prevent and treat syphilis, as well as other STIs, in this Brazilian region.

Seroprevalence of HBV and HCV in female sex workers from four cities in the state of Pará, northern Brazil

Female sex workers (FSWs) represent a high vulnerability group for the acquisition of sexual and parenteral infections such as hepatitis B virus (HBV) and hepatitis C virus (HCV) infections. The present study aimed to determine the prevalence of serological markers and risk factors associated with exposure to HBV and HCV among FSWs in the state of Pará, Brazil. A cross-sectional study using principles of the time location sampling (TLS) method was conducted in four cities (Belém, Bragança, Barcarena, and Augusto Corrêa) of the state of Pará, from 2005 to 2006. In total, 365 FSWs were interviewed using a standardized questionnaire. Blood samples were collected and tested for serological markers of exposure to HBV and HCV using an enzyme immunoassay. The overall prevalence of exposure to HBV and HCV was 36.7% and 7.7%, respectively. The prevalence of surface antigen of HBV was 3.0%. The prevalence of anti-HBc and anti-HBc+ anti-HBs antibodies were 6.3% and 27.4%. Very few (4.7%) FSWs had vaccine immunity against HBV (anti-HBs antibodies only). The prevalence of anti-HCV antibodies was 7.7%. Low monthly income, drug usage, and unprotected sex were some of the social characteristics associated with exposure to the viruses using different analysis. The seroprevalence of HBV and HCV infections among FSWs in four cities of the state of Pará is high when compared to the general population of Brazil, but similar to those found in FSWs in other nondeveloped countries. The prevalence of HBV was higher in Belém, while the prevalence of HCV was higher in the other three cities, highlighting the importance of establishing control and prevention programs to reduce the risk of acquiring these viruses in Pará.

Prevalence and risk factors for HIV-1 infection in people who use illicit drugs in northern Brazil

BACKGROUND

People who use illicit drugs (PWUDs) have a high risk of viral infections. To date, there is a paucity of information on HIV infection among PWUDs in remote Brazilian regions. This study determined the prevalence and factors associated with HIV-1 infection among PWUDs in northern Brazil.

METHODS

Sociodemographic, economic, drug use and health-related information were collected through interviews from a community-recruited, multi-site sample of 1753 PWUDs. The blood samples collected were tested for the presence of HIV-1 using chemiluminescence immunoassay and PCR or western blotting. Logistic regressions identified factors independently associated with HIV-1 infection.

RESULTS

In total, 266 (15.2%) PWUDs were HIV-1 positive. Hepatitis B virus and/or hepatitis C virus nucleic acid was detected in 65 (3.7%) PWUDs infected by HIV-1. The factors associated with HIV-1 infection were male gender, older age, a lower educational level and a lower income, crack cocaine use, a longer drug use history and a history of drug injection and engagement in unsafe sex, sex work and a higher number of sexual partners.

CONCLUSIONS

The current study provides unique, initial insights into HIV and co-infection status and pertinent risk factors among PWUDs in northern Brazil, with clear and diverse implications for urgently improved prevention and treatment intervention needs.

Hepatitis E Virus in People Who Use Crack-Cocaine: A Cross-Sectional Study in a Remote Region of Northern Brazil

People who use crack-cocaine (PWUCC) have numerous vulnerabilities and pose a challenge to health and social assistance services. The exposure to pathogens and risk situations occur differently according to each individual, region and social group. This study identified the presence, genotypes and factors associated with hepatitis E virus (HEV) exposure among a community-recruited cohort of 437 PWUCC in northern Brazil. Epidemiological information was collected through community-based assessments and interviews. Thereafter, blood and fecal samples were collected and tested for HEV using an immunoenzymatic assay, and the genotype was identified by PCR. Logistic regressions were used to identify the risk factors independently associated with exposure to HEV. In total, 79 (18.1%) PWUCC were exposed to HEV: 73 (16.7%) for IgG and six for IgG + IgM. HEV RNA was detected in six fecal samples and in two blood samples from PWUCC with IgM + IgG. Subtype 3c was identified in all of the samples. The factors associated with exposure to HEV were low monthly income, unstable housing (e.g., homelessness), crack-cocaine use ≥40 months, and the shared use of crack-cocaine equipment. The current study provides unique initial insights into HEV status and risk factors among PWUCC in a remote area in Brazil, with diverse implications for urgently improved diagnosis, prevention, and treatment intervention needs.

Oral HPV among people who use crack-cocaine: prevalence, genotypes, risk factors, and key interventions in a remote Northern Brazilian region

OBJECTIVES

This study estimated the prevalence, genotype distribution, and the factors associated with oral human papillomavirus (HPV) in people who use crack-cocaine (PWUCC) in a remote Brazilian region.

MATERIALS AND METHODS

This cross-sectional study used community-based snowball sampling methods for participant recruitment. Socio-demographic, economic, drug use, and health-related information was collected from 278 PWUCC in the cities of Bragança and Capanema in northern Brazil. HPV diagnosis and genotyping were performed by a real-time polymerase chain reaction. Logistic regression identified the factors independently associated with oral HPV.

RESULTS

In total, 111 (39.9%) PWUCC had HPV DNA. Several genotypes were identified, some of them with high oncogenic potential. Crack-cocaine use ≥40 months, unprotected sex, more than 10 sexual partners in the last 12 months, oral sex, exchange of sex for money or illicit drugs, oral mucosa lesions, not having access to public health services, and the absence of vaccination against HPV was all associated with HPV DNA.

CONCLUSIONS

This study identified important epidemiological characteristics of oral HPV infection among PWUCC-a highly marginalized risk population-underlining the high prevalence of oral HPV with oncogenic potential and the urgent need for control and prevention measures, especially vaccination against this virus.

CLINICAL RELEVANCE

It is necessary to understand the prevalence and risk factors of oral HPV in risk populations as people who use crack-cocaine.

Prevalence of syphilis in female sex workers in three countryside cities of the state of Pará, Brazilian Amazon

Background

Syphilis is a sexually transmitted infection (STI) transmitted from person to person mainly by sexual intercourse or through vertical transmission during pregnancy. Female sex workers (FSWs) are exposed especially to syphilis infection, and besides all the efforts to control the spread of STIs, syphilis prevalence is still rising, mainly occurring in low-income countries. This study aimed to investigate the syphilis prevalence, demographic characteristics and sexual habits among FSWs in the Amazon region of Brazil.

Methods

A cross-sectional study was carried out including 184 FSWs from 3 countryside cities of the state of Pará, Amazon region of Brazil. A venereal disease research laboratory test and an indirect immunoenzyme assay to test antibodies against Treponema pallidum were used for screening syphilis infection, while sexual habits and demographic data information were collected through a semi-structured questionnaire. Data was analyzed comparing groups with/without syphilis. Poisson regression models were used to estimate the reasons of prevalence (RP).

Results

The overall prevalence of syphilis was 14.1% (95% CI = 9.8–17.8). FSWs had between 15 and 56 years of age, most were unmarried (65.7%), had attended less than 8 years of formal education (64.1%), had between 10 and 20 partners per week (64.1%), and reported no previous history of STIs (76.1%) and regular use of condom (52.7%). Low level of education attending up to the primary school (RP adjusted = 3.8; 95% CI = 1.4–9.2) and high frequency of anal sex during the past year (RP adjusted = 9.3; 95% CI = 3.5–28.7) were associated with a higher prevalence of syphilis.

Conclusions

A high prevalence of syphilis among FSWs in the Brazilian Amazon region was identified, showing that syphilis is more likely to be transmitted in FSW working in low-income areas, which is attributed to the low level of education. Anal intercourse was found as a risk factor associated with syphilis. Health programs focused on risk populations appear as a rational way to control syphilis spread, which is a rising problem in Brazil and in other several countries.

Hepatitis B Virus Infection among People Who Use Illicit Drugs: Prevalence, Genotypes and Risk Factors in the State of Amapá, Northern Brazil

Background: Several records of high prevalence of HBV have been made in northern Brazil. Among risk groups for viral infection, people who use illicit drugs (PWUDs) stand out, especially if they inject drugs and engage in risky sexual behavior. Objectives: In this study, the prevalence, genotype distribution and factors associated with hepatitis B virus (HBV) exposure in PWUDs were estimated. Methods: This cross-sectional study used snowball sampling from nine different sites. Socio-demographic, economic, drug use and health-related information were collected of 308 PWUDs from nine municipalities in the state of Amapá, northern Brazil. Blood samples were tested for the presence of HBV using enzyme-linked immunosorbent assay (ELISA) and real-time polymerase chain reaction (PCR). Logistic regressions were run to identify factors independently associated with HBV exposure. Results: In total, seventy (22.7%) PWUDs were exposed to HBV, and 12 (3.9%) had DNA HBV. Genotypes A (58.4%), D (33.3%) and F (8.3%) were identified. Age ≥35 years, use of injectable drug, daily use of drugs, use of drugs over 12 years, unprotected sex, exchange sex for money/drugs, and >12 sexual partners in the last 12 months were associated with exposure to HBV. Conclusions: This study identified important information on the epidemiological scenario of HBV infection in PWUDs, highlighting the high prevalence of HBV exposure and the urgent need for measures for control and prevention, especially vaccination against this hepatotropic virus.

Prevalence and Risk Factors for Human Immunodeficiency Virus Infection Among Female Sex Workers: Distinct Offers of Sexual Services in a Municipality of the Brazilian Amazon

This study determined the prevalence of human immunodeficiency virus (HIV) infection and its associated factors in female sex workers (FSWs) from the municipality of Bragança in the state of Pará, Brazil. A cross-sectional study using a respondent-driven sampling method was used to investigate 137 FSWs. They were interviewed using a questionnaire for the collection of data on their characteristics and risk behavior. Blood samples were collected for serological and molecular testing for HIV. Poisson regression models were used to estimate the reasons of prevalence (RP). The majority was single, young, poorly educated, had a low monthly income, and had worked in the sex trade for more than 7 years. Sexual services were offered either directly (easy identification of FSWs in street markets, town squares, street corners, bars, and gas stations) or indirectly/discretely (more complex identification of FSWs, offering services through a cryptic approach or an intermediary). Overall, 22 (16.06%) FSWs had anti-HIV-1/2 antibodies, and 21 (15.33%) also had complementary DNA-HIV. The use of illicit drugs [adjusted RP (aRP) = 3.13; 95% confidence interval (CI) = 1.27-8.41], unprotected sex (aRP = 4.09; 95% CI = 1.34-11.62), anal sex (aRP = 4.01; 95% CI = 1.37-10.15), the exemption of condoms for clients paying extra (aRP = 4.71; 95% CI = 1.52-10.89), more than 7 years working as a sex worker (aRP = 6.04; 95% CI = 1.20-16.33), low levels of education (aRP = 3.55; 95% CI = 1.15-11.02), and a lack of regular medical or gynecological examinations were all associated with HIV infection (aRP = 5.87; 95% CI = 1.26-15.71). The FSWs who offered their services indirectly suffered significantly less physical and sexual aggression, charged more for encounters, had a significantly higher monthly income, and were more likely to have undergone a medical or gynecological examination within the preceding 12 months. This study identified information relevant to the control and prevention of HIV in FSWs.

Hepatitis C virus infection status and associated factors among a multi-site sample of people who used illicit drugs in the Amazon region

BACKGROUND

Elevated rates of Hepatitis C Virus (HCV) infection have been reported in epidemiological studies with people who used illicit drugs (PWUIDs) in different Brazilian regions. In Brazil's Amazon region, studies have already identified the common use of illicit drugs among adolescents and the high prevalence of HCV infections among PWUIDs. However, all studies done with PWUIDs were conducted with small samples and within limited geographic coverage. This study determined the prevalence and risk factors for HCV infection in PWUIDs in the Amazon region, northern Brazil, as well as estimating the prevalence and factors associated with the HCV spontaneous clearance (HSC).

METHODS

This cross-sectional study accessed 1666 PWUIDs from multiple municipalities of the Amazon region. Socio-demographic, economic, drug use and health-related information were collected through interviews. Blood samples collected were tested for the presence of anti-HCV antibodies and RNA-HCV. HCV genotypes were identified by real-time polymerase chain reaction (PCR). Logistic regressions were run to identify factors independently associated with HCV infection status and HSC.

RESULTS

In total, 577 (34.6%) featured HCV antibodies, of which 384 (23.1%) had active HCV infection and 193 (11.6%) indicated HSC. Genotypes 1 (80.2%) and 3 (18.8%) were detected. HCV infection status was associated with the length of illicit drug use history, factors related to parenteral and sexual transmission, and factors of socio-economic marginalization leading to potential risk activities for HCV. HSC was associated with the ethnic (including indigenous) background of participants.

CONCLUSIONS

High levels of HCV infection were detected in PWUIDs. Genotype 1 was predominant. Intense use of illicit drugs, unprotected sexual intercourse, high number of sexual partners and social marginalization were associated with all HCV infection. HSC was associated with origin (Amazonian-born) and non-white (e.g., Black or Indigenous) of PWUIDs. These findings emphasize the need for improve HCV prevention and control services and care for PWUIDs in the Brazilian Amazon region.

Prevalence and genotyping of hepatitis B virus: a cross-sectional study conducted with female sex workers in the Marajó Archipelago, Brazil

In South America, the Amazon basin is considered an endemic area of hepatitis B virus (HBV) infection. However, epidemiological studies with vulnerable groups are scarce. Female sex workers (FSWs) are highly vulnerable to sexually transmitted infections due to a combination of their sexual behavior and socio-economic conditions. Thus, this study investigated the prevalence of HBV infections and HBV–hepatitis C virus, HBV–hepatitis D virus, HBV–HIV, and HBV–human T-lymphotropic virus co-infections among FSWs in the Marajó Archipelago, northern Brazil, as well as identifying the HBV genotypes circulating in this population. A total of 153 FSWs in 5 towns and 18 riverside communities were included in the study. The HBV infection and co-infections were diagnosed by enzyme-linked immunosorbent assay and real-time polymerase chain reaction. The HBV genotypes were detected by sequencing and were then analyzed phylogenetically. Most of the FSWs surveyed were single, young, heterosexual, and born locally, with low levels of education. Overall, 21 (13.7%) had been exposed to HBV, and HBV-DNA was detected in 13 (8.5%). Genotypes A (69.2%), D (23.1%), and F (7.7%) were detected. Seven cases of co-infections with other viruses were detected. These findings indicate a clear need for urgent measures to control the spread of HBV and other pathogens, and to promote the health of the local FSWs.

Genomic Organization of the Repetitive Sequences in Centropomus undecimalis (Perciformes, Centropomidae): Implications for Hybridization and Aquaculture Programs

The family Centropomidae includes a number of fish species of high commercial value. One of these species, Centropomus undecimalis, is a target of artisanal, industrial, and sports fisheries and has also considerable potential for captive breeding, which has led to its inclusion in several aquaculture programs. While the biology and ecology of C. undecimalis are relatively well documented, few karyological data are available on this species, and they are still scarce for other centropomids. The few chromosomal data available on this family indicate a conserved karyotype 2n = 48, but it is unclear whether the chromosome microstructure is also conserved. In this study, new cytogenetic data are presented on C. undecimalis from the Amazon coastal zone, including C-banding, Ag-NOR, in situ hybridization with repetitive DNA probes (5S and 18S ribosomal genes), and telomeric (TTAGGG)n sequences. The diploid number of the species was 2n = 48, with heterochromatic blocks in the centromeric and pericentromeric regions, as well as distal signals; the nucleolus organizer regions (NORs) were associated with the heterochromatic region. The 18S and 5S recombinant DNA (rDNA) clusters were located in the distal region of chromosome pairs 1 and 11, respectively. The similarities of the karyotype macrostructure found among the centropomid species reinforce their exceptional chromosomal stability. However, the presence of heterochromatic blocks and location of NORs suggest the occurrence of structural rearrangements, which indicates that evolutionary dynamics at the microstructural level in this group may be relatively complex and should be evaluated carefully in any study that targets the production of hybrids for aquaculture.

Detection of HCV Persistent Infections in the Dental Pulp: A Novel Approach for the Detection of Past and Ancient Infections

The dental pulp is a sterile highly vascularized tissue and has been commonly used as a biological material to detect the genome of infectious agents that reach the dental tissue. Indeed, the pulp is also used to reveal past and ancient infections in the field of paleomicrobiology. The present study aimed to detect the presence of Hepatitis C virus (HCV) in a small community (approximately 400 inhabitants) in the Amazon region of Brazil (Nossa Senhora do Perpetuo Socorro, Vizeu, Para, Brazil) and standardize a technique for the detection of the virus in the dental pulp. Serum samples were collected from 48 patients whose teeth were clinically recommended for surgical extraction. The group comprised an equal number of males and females, mostly agriculture workers and housewives, respectively. The majority (64.6%) received less than one minimum wage and were ill educated (less than four years of school years). An enzyme immune assay was used to detect antibodies to HCV and the 9 (18.8%) positive samples were submitted to nucleic acid extraction in the blood (using the EXTRAzol) and the pulp (QIAamp DNA Micro Kit e kit RNeasy Plus Micro). The pulp was removed using a modified protocol without the use of liquid nitrogen. Nucleic acid was found in 8 of the dental pulp, but in 7 of the blood samples. Sequencing of one of the samples showed the presence of genotype 1.

CONCLUSIONS

A novel simplified methodology for the extraction and amplification of HCV nucleic acid was successful to detect the presence of persistent infections of the virus within the dental pulp tissue. The protocol may be helpful to detect past and ancient infections and to better understand the natural history of HCV.

Epidemiological aspects of HCV infection in non-injecting drug users in the Brazilian state of Pará, eastern Amazon

BACKGROUND

Currently, sharing of drug paraphernalia is the main form of HCV transmission worldwide. In South America, consistent findings indicate that shared sniffing equipment is an important factor in the spread of HCV among non-injecting drug users. Epidemiological data on the status of HCV infection in illicit drug users in the Amazon region are scarce, although reports of clinical cases of hepatitis or pathologies associated with HCV infection in other population groups are numerous. Thereby, this study investigated the prevalence, genotype frequency, and epidemiological factors associated with HCV infection in non-injecting drug users in the state of Pará, eastern Amazon.

RESULTS

During 2008-2011, 300 non-injecting drug users attending drug-treatment centers participated in this study. Most non-injecting drug users were male (63.7%). The mean age was 32.5 years. The non-injecting drugs most consumed were: cannabis (15.6%), cocaine paste (21.3%), and oxi cocaine (25.7%). Tobacco (60.9%) and alcohol (79.4%) were also commonly consumed. One hundred six (35.1%; CI 95%: 29.8 - 41.1) non-injecting drug users presented anti-HCV antibodies by EIA. The HCV-RNA prevalence was 28.0% (95% CI: 20.6 - 35.8). Genotypes 1 (76.9%) and 3 (23.1%) of HCV have been identified. A multivariate analysis demonstrated that HCV infection was independently associated with the following factors: "age (≥ 35 years)", "tattoos", "use of a needle or syringe sterilized at home", "shared use of drug paraphernalia", "uses drugs for more than 5 years", and "use of drugs everyday".

CONCLUSIONS

This study revealed a high prevalence of HCV infection in non-injecting drug users, and most infections are occasioned by genotype 1. Likely, HCV transmission is associated with the tattoos, the use of needle or syringe sterilized at home by people over the age of 35 years, and sharing, time and frequency of use of non-injecting drugs. These findings should serve as an incentive for the establishment of a program of Hepatitis C prevention and control by the local public-health authorities in order to develop effective policies and strategies for contain the spread of HCV infection.

Human T-cell lymphotropic virus in patients infected with HIV-1: molecular epidemiology and risk factors for transmission in Piaui, Northeastern Brazil

This study aimed to describe the epidemiological, immunological and molecular features of infection by the human T-lymphotropic virus-1/2 (HTLV-1/2) in individuals with HIV-1 in an urban area of Piaui State, Brazil. Exclusion criteria included patients under 18 years of age, pregnant women or Amerindians. Of 805 individuals analyzed by the serological method (ELISA) for the detection of anti-HTLV-1/2, 18 (2.24%) were positive, but only 13 (1.61%) were confirmed by PCR. The RFLP analysis revealed that nine (1.12%) of these subjects were positive for HTLV-1 and four (0.5%) for HTLV-2. The mean age of these co-infected individuals was 50.9±9.1 years, and a significant association was found with age (above 40 years: p = 0.002), minor surgeries (p = 0.004) and blood transfusion (p = 0.031). Quantification of the T CD4+/CD8+ lymphocytes and the HIV-1 viral load showed no significant association of T CD8 + lymphocyte levels with co-infection in the patients with HIV-1/HTLV-1. The sequencing of the LTR region and phylogenetic analysis indicated that the nine HTLV-1 strains belong to the Transcontinental subgroup of the Cosmopolitan group (1a), with a 83% (neighbor-joining) bootstrap value. The HTLV-2 strains were identified as subtype HTLV-2c, supported by a bootstrap value of 79%. Further studies in other population subgroups, such as blood donors and drug users, will be necessary to clarify the dissemination of HTLV-1/2 in Piau and elucidate the developmental profile of the virus in the region.

HCV infection among cocaine users in the state of Pará, Brazilian Amazon

In this study, the prevalence, genotype frequency, and risk factors for HCV infection in 384 cocaine users were determined. One hundred twenty-four (32.3 %) cocaine users had anti-HCV antibodies and 120 (31.3 %) had HCV-RNA. Genotyping results indicated the predominance of genotypes 1 (73.3 %) and 3 (26.7 %). Multivariate analysis showed an association of HCV infection with tattoos, shared use of paraphernalia, daily cocaine use, and a long history of cocaine use. The epidemiological aspects of HCV infection among cocaine users presented here should serve as an incentive for the establishment of a program of hepatitis C prevention and control by the local public-health authorities in the Amazon.