Comprehensive Analysis of Clinically Significant Hepatitis B Virus Mutations in Relation to Genotype, Subgenotype and Geographic Region.

Hepatitis B virus (HBV) is a highly variable DNA virus due to its unique life cycle, which involves an error-prone reverse transcriptase. The high substitution rate drives the evolution of HBV by generating genetic variants upon which selection operates. HBV mutants with clinical implications have been documented worldwide, indicating the potential for spreading and developing their own epidemiology. However, the prevalence of such mutants among the different HBV genotypes and subgenotypes has not been systematically analyzed. In the current study, we performed large-scale analysis of 6,479 full-length HBV genome sequences from genotypes A-H, with the aim of gaining comprehensive insights into the relationships of relevant mutations associated with immune escape, antiviral resistance and hepatocellular carcinoma (HCC) development with HBV (sub)genotypes and geographic regions. Immune escape mutations were detected in 10.7% of the sequences, the most common being I/T126S (1.8%), G145R (1.2%), M133T (1.2%), and Q129R (1.0%). HBV genotype B showed the highest rate of escape mutations (14.7%) while genotype H had no mutations (P < 0.001). HCC-associated mutations were detected in 33.7% of the sequences, with significantly higher frequency of C1653T, T1753V and A1762T/G1764A in genotype G than C (P < 0.001). The overall frequencies of lamivudine-, telbivudine-, adefovir-, and entecavir-resistant mutants were 7.3, 7.2, 0.5, and 0.2%, respectively, while only 0.05% showed reduced susceptibility to tenofovir. In particular, the highest frequency of lamivudine-resistant mutations was observed in genotype G and the lowest frequency in genotype E (32.5 and 0.3%; P < 0.001). The prevalence of HBV mutants was also biased by geographic location, with North America identified as one of the regions with the highest rates of immune escape, antiviral resistance, and HCC-associated mutants. The collective findings were discussed in light of natural selection and the known characteristics of HBV (sub)genotypes. Our data provide relevant information on the prevalence of clinically relevant HBV mutations, which may contribute to further improvement of diagnostic procedures, immunization programs, therapeutic protocols, and disease prognosis.

Hepatotropic viruses (hepatitis A, B, C, D and E) in a rural Brazilian population: prevalence, genotypes, risk factors and vaccination.

BACKGROUND: People living in settlement projects represent an emergent rural population in Brazil. Data on their health is scarce and there are no data on viral hepatitis in this population. This study investigated the epidemiology of viral hepatitis A-E in residents of settlement projects in central Brazil. METHODS: During 2011 and 2012, 923 people living in rural settlements in central Brazil were interviewed and tested to estimate the prevalence of exposure to viral hepatitis A-E, to identify the circulating hepatitis B virus (HBV)/hepatitis C virus (HCV) genotypes and risk factors for HBV exposure and to evaluate adherence to the hepatitis B vaccination series. RESULTS: Overall, 85.9, 3.9, 0.4 and 17.3% of individuals showed evidence of exposure to hepatitis A virus (HAV), hepatitis E virus, HCV and HBV, respectively. Among HBV-DNA positive samples (n=8), subgenotypes A1 (n=3) and A2 (n=1) and genotype D/subgenotype D3 (n=4) were identified. Hepatitis D virus superinfection was detected in 0/16 HBsAg-positive participants. A total of 229 individuals showed serological evidence of HBV vaccination. In total, 442 settlers were eligible for vaccination, but only 150 individuals completed the vaccine series. All anti-HCV-positive samples (n=4) were also HCV-RNA positive and identified as subtype 1a. CONCLUSIONS: The intermediate endemicity of HAV, the higher prevalence of HBV exposure compared with urban areas and the low compliance with HBV vaccination requires preventive measures focused on rural populations, emphasizing the need for HAV and HBV vaccination.

Evidence of hepatitis E virus infections among persons who use crack cocaine from the Midwest region of Brazil.

The current study aimed to determine the seroprevalence of hepatitis E virus (HEV) infection among persons who use crack from Midwest region of Brazil. Sera samples from 698 users of crack, collected from November 2013 to July 2015 were tested for anti-HEV immunoglobulin G (IgG) and immunoglobulin M (IgM) markers. Of the 698 serum samples, 99 (14.2%) were positive for anti-HEV IgG. Two samples were positive for anti-HEV IgM but both were negative for HEV RNA. The variables independently associated with anti-HEV positivity were increasing age and absence of stable partnership. This study showed high prevalence of past hepatitis E virus infection among persons who use crack.

Rodent-borne viruses survey in rural settlers from Central Brazil

Anthropogenic environmental changes arising from settlement and agriculture include deforestation and replacement of natural vegetation by crops providing opportunities for pathogen spillover from animals to humans. This study aimed to investigate the prevalence of rodent-borne virus infections in seven rural settlements from Midwestern Brazil. Of the 466 individuals tested 12 (2.57%) were reactive for orthohantavirus and 3 (0.64%) for mammarenavirus. These rural settlers lived under unfavorable infrastructure, socioeconomic disadvantages, and unsanitary conditions, representing a risk for rodent-borne infections. Development of public policies towards the improvement of health, sanitation and awareness of rodent-borne diseases in improvised camps and settlements is imperative, in order to reduce morbidity and mortality caused by these diseases.

Rodent-borne viruses survey in rural settlers from Central Brazil.

Anthropogenic environmental changes arising from settlement and agriculture include deforestation and replacement of natural vegetation by crops providing opportunities for pathogen spillover from animals to humans. This study aimed to investigate the prevalence of rodent-borne virus infections in seven rural settlements from Midwestern Brazil. Of the 466 individuals tested 12 (2.57%) were reactive for orthohantavirus and 3 (0.64%) for mammarenavirus. These rural settlers lived under unfavorable infrastructure, socioeconomic disadvantages, and unsanitary conditions, representing a risk for rodent-borne infections. Development of public policies towards the improvement of health, sanitation and awareness of rodent-borne diseases in improvised camps and settlements is imperative, in order to reduce morbidity and mortality caused by these diseases.

Risk behaviors for sexually transmitted infections in noninjecting drug users: A cross-sectional study.

The objective of this study was to investigate risk behaviors for sexually transmitted infections (STIs) in noninjecting drug users (NIDUs), using STI diagnosis history as an indicator. A cross-sectional study was conducted in 323 NIDUs of two facilities for alcohol and/or drug dependence treatment in the Goiás State, Central Brazil. All participants were interviewed about risk behaviors and STI history. Multivariable analysis was performed in order to identify predictors of STIs. Adjusted prevalence ratio (APR) with confidence intervals of 95% was obtained using a Poisson regression model. Prevalence of self-reported STIs in the previous 12 months was 25.4% (95% confidence interval [95% CI]: 21.0-30.4%). A multivariable model verified that age (APR: 1.01; 95% CI: 1.00-1.01), sexual contact with partners diagnosed with STIs (APR: 1.27; 95% CI: 1.12-1.45) and injecting drug users (IDUs) (APR: 1.14; 95% CI: 1.14; 95% CI: 1.01-1.31), exchange sex for money and/or drugs (APR: 1.12; 95% CI: 1.02-1.21), and a history of sexual violence (APR: 1.04; 95% CI: 1.04-1.32) were predictors of STIs. Elevated rates of STI history and risk behaviors were observed in NIDUs, supporting the vulnerability of this group for these infections. Public policies and health outreach should be intensified in this population, principally regular STI testing of individuals in treatment for drug dependence and their sexual partners.

Epidemiological and molecular analysis of hepatitis B virus infection in manicurists in Central Brazil.

The aim of this study was to investigate the serological and molecular prevalence of hepatitis B virus (HBV) infection in 514 manicurists/pedicurists and identify the risk factors related with this infection. Samples were tested for HBV serological markers, hepatitis C virus (HCV), and human immunodeficiency virus (HIV) by enzyme-linked immunosorbent assay (ELISA). Anti-HBc-positive samples were tested to investigate occult hepatitis B by PCR. HBsAg-positive samples were genotyped and the viral loads of HBV-DNA positive samples were quantified. The overall HBV prevalence was 5.6% (29/514) and of HBsAg was 0.4% (2/514). One case of occult hepatitis B was found. The genotypes A1 and F2 were identified in two HBsAg-positive samples. Low level of education, not being born in the State of Mato Grosso do Sul and working in the central region of the city were associated with the HBV infection. No single manicurist/pedicurist was infected by HCV or HIV. These findings suggest that despite the exposure to blood contact, this occupation was not associated to an increased risk of acquiring HBV, HCV, and HIV infections.

Emergent predictors of hepatitis C infection among non-injection drug users.

BACKGROUND: Hepatitis C virus (HCV) presents a significant public health issue, especially among high-risk populations, such as truck drivers, prisoners, people living with HIV, people living with tuberculosis, and people who are homeless. METHODS: This cross-sectional study analyzed the data of 1600 individuals recruited from high-risk populations who denied the use of injection drugs and/or history of blood transfusion to better understand on epidemiology of HCV. RESULTS: The presence of HCV antibodies was independently associated with the following risk factors: age >40years, tattoo or body piercing, sharing of personal care items, and non-injection drug use. CONCLUSIONS: While the use of injection drugs is a prevalent mode of HCV transmission, the findings of this study indicate additional routes that lead to viral transmission among vulnerable populations. Since an HCV vaccine is not currently available, public health and education programs should be developed that specifically target high-risk populations to prevent infection acquisition and secondary transmission.

Low prevalence, low immunization and low adherence to full hepatitis B vaccine scheme and high-risk behaviors among crack cocaine users in central Brazil.

Crack cocaine users represent a target group for hepatitis B vaccination. We evaluate the HBV epidemiology, immunization status and compliance with a super-accelerated vaccination schedule among in-treatment crack cocaine users in central Brazil. Six hundred in-treatment crack cocaine users were interviewed, and serum samples were tested for HBV markers. A super-accelerated vaccination schedule of HBV vaccine was offered to all susceptible crack cocaine users. In total, 7.0% of those tested had at least one positive marker of HBV exposure. Age, use of crack cocaine through improvised pipe, exchange of sex for money/drugs and previous sexually transmitted infections (STIs) were predictors of HBV exposure. One hundred six (17.7%) individuals showed a serological profile of hepatitis B vaccination. Of these, 54.7% were less than 25 years old, and only 13% of individuals were more than 35 years old. Although 91.8% of crack users accepted the first vaccine dose, only 21.7% received all three doses. Of the 23 crack cocaine users who agreed to have their vaccine response evaluated, 78.3% developed protective anti-HBs titers. Premature termination of treatment was the most common reason for not receiving the full vaccine series. Despite the low prevalence of HBV exposure among in-treatment crack cocaine users in central Brazil, the low rate of immunization and the high frequency of high-risk behaviors highlight the potential for crack users to acquire and disseminate this infection and therefore maintain the viral reservoir. Health practitioners need to keep this in mind, taking advantage of all opportunities to access this population and vaccinate against HBV.

Prevalence, Risk Behaviors, and Virological Characteristics of Hepatitis B Virus Infection in a Group of Men Who Have Sex with Men in Brazil: Results from a Respondent-Driven Sampling Survey.

BACKGROUND: Men who have sex with men (MSM) are at increased risk of exposure to hepatitis B virus (HBV) compared with the general population. This study aims to assess the epidemiological and virological characteristics of HBV infection in a sample of MSM in Brazil, where data are scarce. METHODS: A cross-sectional study was conducted among MSM in the City of Goiânia, Central Brazil, from March to November 2014, using Respondent-Driven Sampling (RDS). After signing the consent form, participants were interviewed and a blood sample collected. All samples were tested for HBV serological markers and HBV DNA. HBV nucleotide sequence analysis was also performed. RESULTS: A total of 522 MSM were recruited in the study. The prevalence of HBV infection (current or past [presence of anti-HBc marker]) was 15.4% (95% CI: 8.7-25.8) and the rate of HBsAg carriers was 0.6% (95% CI: 0.2-1.6). About 40% (95% CI: 32.3-48.8) of the participants had serological evidence of previous HBV vaccination (reactive for isolated anti-HBs). In addition, 44.3% (95% CI: 36.1-52.9) were seronegative for all HBV markers. Age over 25 years old, receptive anal intercourse, previous sex with women, and history of sexually transmitted infections (STIs) were factors associated with HBV infection. HBV DNA was detected only in HBsAg-positive individuals. HBV isolates were classified into genotype A (subgenotypes A1 and A2), and some mutations were identified throughout the genome. Therefore, occult HBV infection was not observed in the study population. CONCLUSIONS: Public health strategies should be improved for the MSM population in order to prevent HBV and other STIs, as well as to provide appropriate management of patients with active infections.

HIV seroprevalence and high-risk sexual behavior among female sex workers in Central Brazil.

Female sex workers (FSWs) are considered a high-risk group for human immunodeficiency virus (HIV) infection due to their social vulnerability and factors associated with their work. We estimated the prevalence of HIV, and identified viral subtypes and risk factors among FSWs. A cross-sectional study using respondent-driven sampling (RDS) method was conducted among 402 FSWs in Campo Grande city, Brazil, from 2009 to 2011. Participants were interviewed using a standardized questionnaire about sociodemograpic characteristics and risk behavior. Blood samples were collected for serological testing of HIV. Of the 402 FSWs, median age and age of initiating sex work were 25 years (Interquartile range [IQR]: 9) and 20 years (IQR: 6), respectively. The majority reported use of alcohol (88.5%), had 5-9 years (median: 9; IQR: 3) of schooling (54.5%), 68.6% had tattoos/body piercings, and 45.1% had more than seven clients per week (median: 7; IQR: 10). Only 32.9% of FSW reported using a condom with nonpaying partners in the last sexual contact. Prevalence of HIV infection was 1.0% (95% CI: 0.1-2.6%). Genotyping for HIV-1 performed on three samples detected subtypes B, C, and F1. Sex work in the Midwestern region of Brazil is characterized by reduced education, large numbers of clients per week, and inconsistent condom use, mainly with nonpaying partners. Although prevalence of HIV infection is currently low, elevated levels of high-risk sexual behavior confirm a need to implement prevention measures. Specific interventions targeting FSWs must emphasize the risk associated with both clients and nonpaying partners while providing knowledge about HIV prevention.

Presence of maternal anti-HBs antibodies does not influence hepatitis B vaccine response in Brazilian neonates.

Recently, it was suggested that maternal hepatitis B surface antigen antibodies (anti-HBs) acquired transplacentally could play a negative role in newborn infants' immune response to the hepatitis B vaccine. We compared the hepatitis B virus (HBV) vaccine response in infants born to mothers previously vaccinated against HBV (n = 91) to infants born to mothers who were not previously vaccinated (n = 221). All newborn infants received three intramuscular doses (10 µg) of HBV vaccine (Butang®) at 0,1 and six months. The first dose was administered at the maternity hospital within 12 h of birth. The geometric mean titres of anti-HBs were not different among newborn infants born to mothers who were anti-HBs-negative (492.7 mIU/mL) and anti-HBs-positive (578.7 mIU/mL) (p = 0.38). Eight infants did not respond to the HBV vaccine. Of them, six were born to anti-HBs-negative mothers and two were born to mothers with anti-HBs titres less than 50 mlU/mL. Despite the mother's anti-HBs-positive status, our data show a good immunogenicity of the Brazilian HBV recombinant vaccine in neonates.

Presence of maternal anti-HBs antibodies does not influence hepatitis B vaccine response in Brazilian neonates

Recently, it was suggested that maternal hepatitis B surface antigen antibodies (anti-HBs) acquired transplacentally could play a negative role in newborn infants' immune response to the hepatitis B vaccine. We compared the hepatitis B virus (HBV) vaccine response in infants born to mothers previously vaccinated against HBV (n = 91) to infants born to mothers who were not previously vaccinated (n = 221). All newborn infants received three intramuscular doses (10 μg) of HBV vaccine (Butang®) at 0,1 and six months. The first dose was administered at the maternity hospital within 12 h of birth. The geometric mean titres of anti-HBs were not different among newborn infants born to mothers who were anti-HBs-negative (492.7 mIU/mL) and anti-HBs-positive (578.7 mIU/mL) (p = 0.38). Eight infants did not respond to the HBV vaccine. Of them, six were born to anti-HBs-negative mothers and two were born to mothers with anti-HBs titres less than 50 mlU/mL. Despite the mother's anti-HBs-positive status, our data show a good immunogenicity of the Brazilian HBV recombinant vaccine in neonates.

Hepatitis C virus infection in Brazilian long-distance truck drivers.

Hepatitis C virus (HCV) infection is a global public health problem. Long-distance truck drivers live apart from their family for long periods of time, a lifestyle that favors at-risk behaviors such as unprotected sex with multiple partners and illicit drug use. As data concerning HCV infection in this population are still rare, this paper aims to investigate the prevalence, genotypes/subtypes, and the factors associated with HCV infection in long-distance truck drivers in Brazil. A cross-sectional survey was carried out with 641 Brazilian long-truck drivers who were recruited at a major truck stop located at kilometer 1,296 of the BR-153 highway, which is considered to be one of the longest roads in Brazil. All individuals were interviewed, and their serum samples were tested for the presence of antibodies to HCV (anti-HCV) by ELISA and immunoblot. Anti-HCV positive samples were tested for HCV RNA by PCR amplification of the 5' NC and NS5B regions and were genotyped using the LiPA assay and nucleotide sequencing, respectively. Factors associated with HCV infection were identified with logistic regression. The prevalence of HCV infection was 1.4% (95% CI: 0.7-2.8). History of blood transfusion, sharing of personal hygiene tools, illicit drug use and HBV status were factors independently associated with HCV infection in the study population. HCV RNA was detected in 8/9 anti-HCV positive samples, in which genotypes 1 (n = 3), 2 (n = 2), and 3 (n = 3) were determined by LiPA. Using phylogenetic tree analysis of the NS5B region, subtypes 1a (n = 1), 1b (n = 2), 2b (n = 2) and 3a (n = 3) were identified. These data show that the prevalence of HCV infection among Brazilian truck drivers was similar to that observed for the general population. History of blood transfusion, sharing of personal hygiene tools, illicit drug use and HBV status were predictors of HCV infection. The HCV genotypes/subtypes identified in the study population are consistent with those circulating in Brazil.

Prevalence, risk factors and genotypes of hepatitis C virus infection among drug users, Central-Western Brazil.

OBJECTIVE: To estimate prevalence of hepatitis C virus (HCV) infection and identify risk factors associated and circulating HCV genotypes and subtypes. METHODS: Study conducted including 691 drug users attending 26 charitable, private and public drug treatment centers in Goiânia and Campo Grande, central-western Brazil, between 2005 and 2006. Sociodemographic characteristics and risk factors for HCV infection were collected during interviews. Blood samples were tested for HCV antibodies (anti-HCV). Positive samples were submitted to HCV RNA detection by PCR with primers complementary to 5' NC and NS5B regions of viral genome and genotyped by line probe assay (LiPA) and direct nucleotide sequencing followed by phylogenetic analysis. The prevalence and odds ratio were calculated with 95% confidence intervals. Risk factors were first estimated in the univariate analysis (p<0.10) and then analyzed by hierarchical logistic regression. Statistical significance was assessed at a 5% significance level. RESULTS: The prevalence of anti-HCV was 6.9% (95% CI: 5.2-9.2). The multivariate analysis of risk factors revealed that age over 30 years and injecting drug use were associated with HCV infection. HCV RNA was detected in 85.4% (41/48) of anti-HCV-positive samples. Thirty-three samples were genotyped as genotype 1 by LiPA, subtypes 1a (63.4%) and 1b (17.1%), and 8 samples (19.5%) were genotype 3, subtype 3a. The phylogenetic analysis of the NS5B region showed that 17 (68%), 5 (20%), and 3 (12%) samples were subtypes 1a, 3a, and 1b, respectively. CONCLUSIONS: The results show a high prevalence of HCV infection and predominance of subtype 1a among drug users in Brazil. In addition, injecting drug use was a major risk factor associated with HCV infection.

Prevalência, fatores de risco e genótipos da hepatite C entre usuários de drogas / Prevalencia, factores de riesgo y genotipos de la hepatitis C entre usuarios de drogas / Prevalence, risk factors and genotypes of hepatitis C virus infection among drug users, Central-Western Brazil

OBJETIVO: Avaliar a utilização da Escala de Depressão Pós-natal de Edimburgo como instrumento de triagem no sistema público de saúde. MÉTODOS: A Escala foi administrada entre o 40° e 90° dia do pós-parto, a 245 mulheres que tiveram parto em uma maternidade privada no município de Belo Horizonte (MG), entre 2005 e 2006. As participantes foram submetidas a uma entrevista psiquiátrica estruturada (Mini-Plus 5.0) utilizada como padrão-ouro para diagnóstico de depressão. Foram calculadas sensibilidade e especificidade da escala e utilizou-se a curva ROC para achar o melhor ponto de corte. Foi utilizado o teste t de Student para comparação das variáveis numéricas e o qui-quadrado para as variáveis categóricas. A confiabilidade foi aferida pelo coeficiente de consistência interna alfa de Cronbach. RESULTADOS: Foram diagnosticadas 66 mulheres com o quadro depressivo pós-parto (26,9 por cento da amostra). Não houve diferença entre mulheres com e sem depressão pós-parto em relação à idade, escolaridade, número de partos anteriores e estado civil. Utilizando-se o ponto de corte de 10, a sensibilidade da escala foi 86,4, a especificidade 91,1 e o valor preditivo positivo 0,78. CONCLUSÕES: As propriedades psicométricas da Escala a carcterizam como um bom instrumento de triagem da depressão pós-parto e seu uso disseminado no Sistema Único de Saúde poderia repercutir positivamente com aumento significativo na taxa de reconhecimento, diagnóstico, e tratamento da depressão pós parto.

Compliance with and response to hepatitis B vaccination in remaining quilombo communities in Central Brazil.

Compliance with and responses to the hepatitis B vaccine were evaluated in remaining quilombo communities in Central Brazil. A total of 708 individuals who were susceptible to hepatitis B virus infection were invited to participate in the hepatitis B vaccination program in eight communities. Although 567 (80%) individuals received the first dose, only 198 (28%) complied with the full vaccination scheme. Of 148 subjects who agreed to be tested for anti-HBs, 123 (83.1%; 95%CI: 75.9-88.6) responded to the vaccine. A geometric mean titer of 512mIU/mL (95%CI: 342.5-765.3) was found. Male sex and older age were independently associated with non-response. Additional health education programs and alternative hepatitis B vaccine schedules are needed to improve the vaccination coverage in these communities in Central Brazil.

Compliance with and response to hepatitis B vaccination in remaining quilombo communities in Central Brazil / Adesão e resposta à vacinação contra hepatite B em comunidades remanescentes de quilombos no Brasil Central

Compliance with and responses to the hepatitis B vaccine were evaluated in remaining quilombo communities in Central Brazil. A total of 708 individuals who were susceptible to hepatitis B virus infection were invited to participate in the hepatitis B vaccination program in eight communities. Although 567 (80 percent) individuals received the first dose, only 198 (28 percent) complied with the full vaccination scheme. Of 148 subjects who agreed to be tested for anti-HBs, 123 (83.1 percent; 95 percentCI: 75.9-88.6) responded to the vaccine. A geometric mean titer of 512mIU/mL (95 percentCI: 342.5-765.3) was found. Male sex and older age were independently associated with non-response. Additional health education programs and alternative hepatitis B vaccine schedules are needed to improve the vaccination coverage in these communities in Central Brazil.

A adesão e resposta à vacina contra hepatite B foram avaliadas em comunidades remanescentes de quilombos no Brasil Central. Um total de 708 indivíduos suscetíveis à infecção pelo vírus da hepatite B foi convidado para participar do programa de vacinação contra hepatite B em oito comunidades. Apesar de 567 (80 por cento) indivíduos terem recebido a primeira dose, somente 198 (28 por cento) aderiram ao esquema completo de vacinação. De 148 sujeitos que concordaram em dosar o anti-HBs, 123 (83,1 por cento; IC95 por cento: 75,9-88,6) responderam à vacina. Um título geométrico médio de 512mUI/mL (IC95 por cento: 342,5-765,3) foi encontrado. Sexo masculino e idade foram independentemente associados com ausência de resposta. Programas adicionais de educação em saúde e esquemas alternativos de vacinação contra hepatite B são necessários para melhorar a cobertura vacinal nessas comunidades no Brasil Central.

Prevalence of hepatitis B virus and risk factors in Brazilian non-injecting drug users.

Non-injecting drug users are at high-risk for acquiring hepatitis B virus (HBV), although the factors contributing to this increased risk are not known. In the present study, the overall and occult HBV infection prevalence rates were determined in a large population of non-injecting drug users in the Central-West region of Brazil. HBV genotypes and predictors of infection were also identified. A total of 852 individuals in 34 drug treatment centers were interviewed, and their serum samples were tested for the presence of HBV markers by ELISA. HBsAg and anti-HBc-positive samples were tested for HBV DNA by PCR. Samples with HBV DNA were genotyped by restriction fragment length polymorphism (RFLP). The overall prevalence of HBV infection was 14% (95% CI: 11.7-16.5). A multivariate analysis of risk factors showed that age >30 years, non-white race/ethnicity, duration of drug use >10 years, lifetime number of sexual partners >10, non-use of condoms, and HCV and HIV status were associated significantly with HBV infection. Of the 9 (1%) HBsAg-reactive samples, HBV DNA was present in 2/2 of HBeAg-positive and in 5/7 anti-HBe-positive samples. An occult HBV infection rate of 2.7% (3/110) was found among anti-HBc-positive individuals. All HBV DNA-positive samples were genotyped: seven were genotype A, two were genotype D, and one was genotype F. Finally, few individuals (8%) had serological evidence of a previous HBV vaccination. These findings indicate that preventive interventions are needed for both sexual and drug-related high-risk behavior. Additionally, non-injecting drug users should be targeted for HBV vaccination.