Risk factors for hepatitis B virus infection in Rio de Janeiro,Brazil

Background  

Despite international efforts to prevent hepatitis B virus (HBV) infection through global vaccination programs, new cases are still being reported throughout the world.     

Knowledge of AIDS and HIV transmission among drug users in Rio de Janeiro, Brazil

Background  

Proper knowledge of HIV transmission is not enough for people to adopt protective behaviors, but deficits in this information may increase HIV/AIDS vulnerability.     

Age-specific seroprevalence of HIV, hepatitis B virus, and hepatitis C virus infection among injection drug users admitted to drug treatment in 6 US cities

OBJECTIVES: This study measured age-specific seroprevalence of HIV, hepatitis B virus, and hepatitis C virus (HCV) infection among injection drug users (IDUs) admitted to drug treatment programs in 6 US cities. METHODS: Remnant sera collected from persons entering treatment with a history of illicit drug injection were tested for antibodies to HIV, hepatitis C (anti-HCV), and hepatitis B core antigen (anti-HBc). RESULTS: Prevalence of anti-HBc and anti-HCV increased with age and reached 80% to 100% among older IDUs in all 6 cities. Although overall age-specific HIV prevalence was lower than anti-HCV or anti-HBc, this prevalence was greater in the Northeast than in the Midwest and West. CONCLUSIONS: The need continues for effective primary prevention programs among IDUs specifically targeting young persons who have recently started to inject drugs.     

An epidemic of hepatitis B virus infection among intravenous drug users in Iceland

This study describes an outbreak of hepatitis B primarily among intravenous drug users in Iceland which has a population with a very low incidence of hepatitis B virus infection. The incidence of acute hepatitis B is generally low in the Nordic Countries, in the order of one to five cases per 100,000 people per year. Between 1989 and 1992 there was an outbreak of hepatitis B virus infection primarily among the intravenous drug user (IVDU) population in Iceland. At the Department of Medical Virology, University of Iceland there were 44 cases of acute hepatitis B identified during the peak year 1990, an incidence of 16.9 cases of acute hepatitis B per 100,000 people. 63.6% of these were known to be IVDUs. The seroprevalence of the hepatitis B core antibody (anti-HBc) marker was assessed among 1100 randomly selected individuals. The average prevalence of this marker was 2.9% and rose from zero at the age of 15 and younger to 6.5% at the age of 65 and older. Among IVDUs attending a detoxification clinic in 1990 the prevalence of the anti-HBc was 32%. In contrast, those attending the same clinic, due to alcoholism only, did not have a significantly higher prevalence of anti-HBc than the group used for comparison.     

Monitoring the hepatitis A virus in urban wastewater from Rio de Janeiro, Brazil

Hepatitis A is a viral disease with a significant public health impact, especially in developing countries. Improvements in sewage services could prevent hepatitis A virus (HAV) dissemination into the environment and minimize the risk of infection. The aim of this study was to monitor HAV for one year in urban sewage samples from the largest wastewater treatment plant in Rio de Janeiro, Brazil, to assess environmental contamination with HAV and its dissemination after treatment by an activated sludge process. For this purpose, 48 samples (24 raw sewage samples and 24 treated effluent samples) were collected from August 2009 to July 2010 for HAV detection. Using quantitative real-time PCR 14 (58%) raw sewage samples were positive for HAV, and the highest viral genome loads were detected in the spring and summer. HAV was not detected in treated effluent samples, which suggests that the viral loads observed could be easily removed by the activated sludge process, thus preventing the dissemination of HAV into the environment. All of the HAV strains sequenced belonged to subgenotype IA, which clustered closely with Brazilian and Argentine HAV strains. These data demonstrate that environmental monitoring can be a useful tool in epidemiological studies.     

Risk of hepatitis C virus infection among young adult injection drug users who share injection equipment

Designing studies to examine hepatitis C virus (HCV) transmission via the shared use of drug injection paraphernalia other than syringes is difficult because of saturation levels of HCV infection in most samples of injection drug users (IDUs). The authors measured the incidence of HCV infection in a large cohort of young IDUs from Chicago, Illinois, and determined the risk of HCV seroconversion associated with specific forms of sharing injection paraphernalia. From 1997 to 1999, serum samples obtained from 702 IDUs aged 18-30 years were screened for HCV antibodies; prevalence was 27%. Seronegative participants were tested for HCV antibodies at baseline, at 6 months, and at 12 months. During 290 person-years of follow-up, 29 participants seroconverted (incidence: 10.0/100 person-years). The adjusted relative hazard of seroconversion, controlling for demographic and drug-use covariates, was highest for sharing "cookers" (relative hazard = 4.1, 95% confidence interval: 1.4, 11.8), followed by sharing cotton filters (relative hazard = 2.4, 95% confidence interval: 1.1, 5.0). Risks associated with syringe-sharing and sharing of rinse water were elevated but not significant. After adjustment for syringe-sharing, sharing cookers remained the strongest predictor of seroconversion (relative hazard = 3.5, 95% confidence interval: 1.3, 9.9). The authors conclude that sharing of injection equipment other than syringes may be an important cause of HCV transmission between IDUs.     

High prevalence of chronic hepatitis B infection among injection drug users in Iran: the need to increase vaccination of adults at risk

We measured the prevalence of HBV surface antigen (HBsAg) among male injection drug users (IDUs) in Detention, Tehran, Iran. A cross-sectional survey included 499 male IDUs arrested by police during a predetermined police sweep in Tehran (February, 2006). A questionnaire was filled out for each individual. Blood specimens were collected for HBsAg testing. Prevalence of HBsAg was 5.8% (95% CI 3.6-7.9). The majority of chronic HBV infections, 69.2%, were among adults age 25 to 34 years. The high prevalence of HBsAg highlights the need for special efforts to increase vaccination among adult populations at risk for HBV infection in order to reducing continuing transmission and stave off future high burden of disease.     

Epidemiology of hepatitis C virus infection among injecting drug users in Australia.

STUDY OBJECTIVE: To review the epidemiology of hepatitis C virus (HCV) infection among injecting drug users (IDUs) in Australia, and consider needs for further research and prevention policies and programmes. DESIGN: (1) Review of the results of surveillance for HCV; (2) review of published literature on prevalence, incidence, and risk factors for HCV among IDUs; and (3) reconstruction of incidence rates from prevalence studies of HCV in IDUs. SETTING AND PARTICIPANTS: Field and clinic based studies of IDUs in Australia. MAIN RESULTS: HCV has been present at high prevalences (of the order of 60-70%) in populations of Australian IDUs since at least 1971. Duration of injecting and main drug injected were the main predictors of seropositivity, the latter possibly a surrogate for frequency of injecting and both together as surrogate for cumulative numbers of times injected. Risk of infection begins with first injection and continues as long as injecting does. Current incidence is approximately 15 per 100 person years, and up to 40 per 100 person years in some subpopulations. Incidence may have decreased through the 1980s as a result of behaviour change in relation to HIV, as it has for hepatitis B, but not significantly so. CONCLUSIONS: Control of HCV infection in Australia will depend on effectiveness of measures to control HCV spread among IDUs. This will be a greater challenge than the control of HIV in this population has been. Needs identified include improved surveillance, especially for recently acquired infection, better understanding of exact transmission modes, and urgent improvement in prevention strategies.     

Risk factors for hepatitis B in an outbreak of hepatitis B and D among injection drug users

During January-April, 2000, 12 cases of acute hepatitis B were reported in Pierce County, Washington, compared with seven in all of 1999. Seven (58.3%) case patients were injection drug users (IDUs), three of whom were coinfected with hepatitis D virus (HDV) and died of fulminant hepatitis. Vaccination clinics were implemented at the local health department and needle exchange program to control the outbreak. We investigated this outbreak to determine risk factors for hepatitis B virus (HBV) transmission among IDUs. Hepatitis B cases were ascertained through routine surveillance and prevaccination testing at vaccination clinics. We conducted a case-control study comparing IDU case patients with HBV-susceptible IDUs identified at the vaccination clinics. Fifty-eight case patients were identified during January-December, 2000, 20 (34.5%) of whom were coinfected with HDV. Thirty-eight case patients (65.5%) reported current IDU. In the case-control study, the 17 case patients were more likely than the 141 controls to report having more than one sex partner [odds ratio (OR) =4.8, 95% confidence interval (CI) =1.5-15.0], injecting more than four times a day (OR = 4.5, 95% CI =1.2-15.6) and sharing drug cookers with more than two people (58.8% vs. 14.0%, OR =14.0, 95% CI =2.4-81.5). Results were similar after controlling for syringe sharing in multivariable analysis. IDUs should be vaccinated against hepatitis B and should be advised against sharing drug injection equipment.     

Income inequality and homicide rates in Rio de Janeiro, Brazil.

OBJECTIVES: This study determined the effect of income inequality on homicide rates in the state of Rio de Janeiro, Brazil. METHODS: We conducted an ecological study at 2 geographical levels, municipalities in the state of Rio de Janeiro and administrative regions in the municipality of Rio de Janeiro. The association between homicide and income inequality was tested by multiple regression procedures, with adjustment for other socioeconomic indicators. RESULTS: For the municipalities of Rio de Janeiro State, no association between homicide and income concentration was found an outcome that can be explained by the municipalities' different degrees of urbanization. However, for the administrative regions in the city of Rio de Janeiro, the 2 income inequality indicators were strongly correlated with the outcome variable (P < .01). Higher homicide rates were found precisely in the sector of the city that has the greatest concentration of slum residents and the highest degree of income inequality. CONCLUSIONS: The findings suggest that social policies specifically aimed at low-income urban youth, particularly programs to reduce the harmful effects of relative deprivation, may have an important impact on the homicide rate.     

Case-reporting of acute hepatitis B and C among injection drug users

Although public health surveillance system data are widely used to describe the epidemiology of communicable disease, occurrence of hepatitis B and C virus (HBV and HCV, respectively) infections may be misrepresented by under-reporting in injection drug users (IDUs). This study was carried out to examine the relationship between HBV and HCV incidence and case-reporting of hepatitis B and C in Seattle IDUs. Names of participants in a Seattle IDU cohort study who acquired HBV or HCV infection over a 12-month follow-up period were compared to a database of persons with acute bepatitis B and C reported to the bealth department surveillance unit over the same period. Of 2,208 IDUs enrolled in the cohort who completed a follow-up visit, 63/759 acquired HBV infection, 53/317 acquired HCV infection, and 3 subjects acquired both HBV and HCV. Of 113 cohort subjects who acquired HBV or HCV, only 2 (1.5%) cases were reported; both bad acute bepatitis B. The upper 95% confidence limit for case-reporting of bepatitis C in the cohort was 5.7%, and for hepatitis B, it was 7.5%. In this study, reporting of acute bepatitis in IDUs was extremely low, raising questions regarding the use of community surveillance data to estimate underlying incidence in that population group.     

An epidemic of hepatitis B among injection drug users in a rural area.

An epidemic of hepatitis B occurring in a rural area of Nova Scotia in 1988 and 1989 was investigated. This epidemic identified injection drug use (IDU) as the major determinant of transmission and was the first highly visible indication of IDU in rural Nova Scotia. Contact-tracing was used to identify 186 injection drug users (IDUs), of whom 153 (82%) were interviewed. Of 133 (72%) IDUs who underwent serological testing, 78 had serological evidence of hepatitis B infection. Using epidemiological criteria, 57 IDUs formed a cluster of hepatitis B infections. Using logistic regression techniques, age (O.R. = 1.1), the total number of IDU-contacts named (O.R. = 1.1), and the number of hepatitis B seropositive IDU-contacts named (O.R. = 1.3), were identified as risk factors predictive of an IDU being a cluster case. The characterization of this epidemic may be useful as a model for the spread of hepatitis B and other viral infections among IDUs in rural areas.     

Low incidences of human immunodeficiency virus and hepatitis C virus infection and declining risk behaviors in a cohort of injection drug users in Chennai, India

The authors characterized human immunodeficiency virus (HIV) and hepatitis C virus (HCV) incidence and prospective changes in self-reported risk behavior over 2 years among 1,158 injection drug users (IDUs) recruited in Chennai, India, in 2005-2006. At baseline, HIV prevalence was 25.3%, and HCV prevalence was 54.5%. Seropositive persons with prevalent HIV infection were used to estimate baseline HIV incidence by means of the Calypte HIV-1 BED Incidence EIA (Calypte Biomedical Corporation, Portland, Oregon). Longitudinal HIV and HCV incidence were measured among 865 HIV-negative IDUs and 519 HCV antibody-negative IDUs followed semiannually for 2 years. Participants received pre- and posttest risk reduction counseling at each visit. Estimated HIV incidence at baseline was 2.95 per 100 person-years (95% confidence interval (CI): 1.21, 4.69) by BED assay; observed HIV incidence over 1,262 person-years was 0.48 per 100 person-years (95% CI: 0.17, 1.03). HCV incidence over 645 person-years was 1.71 per 100 person-years (95% CI: 0.85, 3.03). Self-reported risk behaviors declined significantly over time, from 100% of participants reporting drug injection at baseline to 11% at 24 months. In this cohort with high HIV and HCV prevalence at enrollment, the authors observed low incidence and declining self-reported risk behavior over time. While no formal intervention was administered, these findings highlight the potential impact of voluntary counseling and testing in a high-risk cohort.     

2013年西安市强制戒毒人员乙型肝炎病毒感染及疫苗接种状况调查

目的 调查西安市强制戒毒人员乙型肝炎(简称乙肝)病毒(HBV)感染现状及乙肝疫苗接种情况.方法 于2013年3-6月,对西安市某家强制戒毒所所内的545名强制戒毒人员进行问卷调查,采集静脉血3 ～5 ml,检测其乙肝表面抗原(HBsAg)、核心抗体(抗-HBc)和表面抗体(抗-HBs),比较不同特征调查对象HBV感染指标阳性率及疫苗接种率差异.结果 HBsAg、抗-HBc、抗-HBs的阳性率分别为29.4％(160/545)、60.0％(327/545)、56.1％(306/545),3项均为阴性者85名(15.6％).注射吸毒者HBsAg阳性率为40.0％(94/235),抗-HBc阳性率为65.5％(154/235),均高于非注射吸毒者[21.6％ (52/241)、58.5％(141/241)]和注射、非注射混用者[20.3％(14/69)、46.4％ (32/69)](x2值分别为23.52、9.02,P值均＜0.05).强制戒毒前1年内吸毒频次≥1次/d者HBsAg阳性率[30.6％ (153/500)]高于2～3次/周者[15.6％ (7/45)](x2=4.51,P＜0.05).乙肝疫苗接种率为11.7％ (64/545).小学以下文化程度调查对象的接种率[3.5％ (5/141)]低于高中以上[10.9％ (14/128)]和初中文化程度[16.3％ (45/276)](x2=26.61,P＜0.05).≥45岁组接种率[7.8％ (12/153)]低于＜30[15.9％ (21/132)]、30 ～44[11.9％ (31/260)]岁组(x2=30.36,P＜0.05).接种者抗-HBs阳性率[73.4％(47/64)]高于未接种者[53.8％ (259/481)](x2=8.81,P=0.003),其HBsAg阳性率[16.7％ (11/64)]低于未接种者[31.0％ (149/481)](x2=5.18,P=0.023).结论 西安市强制戒毒人员HBV感染状况较严重,乙肝疫苗接种率较低.     

静脉注射毒品人群中HIV、HBV和HCV感染的现况研究

目的了解静脉注射毒品人群中人类免疫缺陷病毒（HIV）、乙型肝炎病毒（HBV）和丙型肝炎病毒（HCV）的感染情况。方法从四川、湖南、广西和新疆等地静脉注射毒品人群中采集血液样本2025份，应用酶联免疫试剂盒检测抗-HIV、抗-HCV抗体和HBsAg。结果红静脉沣射毒品人群中，抗-HIV、抗-HCV及HBsAg的阳性率分别为14．7％～30．4％、60．7％～85．5％和6．6％～22．4％，其HIV／HBV、HIV/HCV、HCV／HBV和HIV／HCV／HBV合并感染率分别为0％～0．4%、11．6％～27．2％、2．3％～14．3％和1．6％～4．8％。结论静脉注射毒品人群中HIV、HBV和HCV的感染率均高于正常人群，其中HIV与HCV合并感染率最高。     

A modelling analysis of pertussis transmission and vaccination in Rio de Janeiro, Brazil

Pertussis is an infectious respiratory disease for which mass vaccination is an effective preventive strategy. In many developed countries, where high vaccination coverage has been maintained for approximately 50 years, re-emergence of the disease has been observed in all age groups. In the municipality of Rio de Janeiro (RJ), where vaccination started in the 1980s, surveillance data show no sign of disease re-emergence. We developed a mathematical model that incorporates the major demographic aspects of a large urban centre in a developing nation, in addition to the most important epidemiological aspects of disease transmission. Parameter values were estimated based on RJ demographic and vaccine coverage data. Overall, all vaccination strategies determined a major decrease (over 95% decrease when compared to the pre-vaccine era) in the incidence of primary infections (occurring in individuals who have never been immunized through infection or vaccine). On the other hand, the strategies (a) three doses at age 2-11 months, (b) three doses plus booster at age 12-23 months, (c) three doses plus booster at age 4-5 years, and (d) three doses plus both boosters, differently affected the incidence of secondary infections (occurring in previously infected/vaccinated individuals). Given that the immunity against pertussis wanes with time and that the infectious agent has not been eliminated from the population, it is expected that pertussis will continue to be a problem in RJ. Actually, since immunity acquired from vaccine wanes faster than disease-acquired immunity and the possibility of natural boosters has decreased with mass vaccination, an increase in the incidence of secondary infections among older age groups is expected (and predicted by the model). Possible explanations as to why this dynamics is not captured by the RJ surveillance system are discussed. A poorly effective surveillance system and a lack of awareness regarding loss of immunity and the possibility of pertussis infection in older age groups are among them. Finally, we bring attention to the need of (i) field studies for the measurement of pertussis incidence in adolescents and adults; (ii) better understanding of the transmission dynamics currently occurring in RJ, and (iii) re-evaluation of vaccination strategies with the possible introduction of acellular vaccines for the vaccination of older individuals.     

Behavior and major barriers faced by non-injectable drug users with HBV/HCV seeking treatment for hepatitis and drug addiction in Rio de Janeiro, Brazil

Drug users (DU) are a marginalized group and at risk for viral hepatitis, who seldom access health services. A cross-sectional survey was conducted with 111 DU with chronic HBV/HCV and 15 in-depth interviews with health professionals/policymakers in Rio de Janeiro, Brazil. Most interviewees were male, non-white, with a low educational background, unemployed and/or living on less than $245 a month (minimun wage). In the last 6 months, 61.8% of interviewees snorted cocaine, 64.7% at least once a week. Half of the interviewees had a stable partner and 38.3% of those with occasional partners never/almost never using condoms. Addiction treatment seeking was found to be associated with: being white (OR:5.5), high-school degree (OR:8.7), and employment (OR:5.7). Hepatitis treatment seeking was high (80.9%), and access to low-threshold, user-friendly health services was key for treatment seeking behaviors (OR:3.6). Missed opportunities for hepatitis treatment seem to be associated with structural (uneven political/financial support to hepatitis programs) and patient-related barriers (severe addiction and non-adherence). Those most in need were less likely to access treatment, calling for renewed strategies, in order to curb hepatitis among impoverished drug users and their sexual partners.     

Acceptance and completion of hepatitis B vaccination among drug users in New York City

Hepatitis B (HBV) vaccination rates remain low among drug users. We examined correlates of vaccine acceptance and completion in two ongoing prospective studies of young injecting and non-injecting drug users in New York City. Street recruited drug users were enrolled at one of two neighbourhood locations (Harlem and the Bronx) between 2000 and 2004 and completed risk behaviour questionnaires and HBV testing. Free HBV vaccination was offered. Among 1117 participants, 26.1% (275) had a previous HBV infection, 57.9% (610) were susceptible to HBV, and 16.0% (169) had serological evidence of previous vaccination. Of the 610 participants susceptible to HBV, 466 (76.4%) returned for their results and were offered vaccination; 53.9% (251) received at least one dose of the vaccine (acceptors). Correlates of vaccine acceptance included older age, public assistance as main income source, and being recruited in the Bronx. Daily crack users were significantly less likely to initiate the vaccine series. Among 240 vaccine acceptors, 98 (40.8%) completed all three doses. Daily injectors, Hispanics, and those recruited in Harlem were less likely to complete the vaccination series. HBV vaccination acceptance among drug users seems likely in programmes that are convenient and offer remuneration; however, extended efforts are needed to improve series completion.     

吸毒人群中甲肝病毒感染及其影响因素

目的　了解吸毒人员中甲型肝炎病毒 (HAV)的感染状况及其影响因素 ,为防制甲肝提供科学依据。方法　采用现况研究 ,通过整群抽样 ,以问卷的方式收集吸毒人员有关资料并采集血标本。用酶联免疫吸附试验(ELISA法 ) ,检测血清中抗 -HAV。采用SPSS 10 0软件进行统计学分析。结果　 772名吸毒人员中检出阳性 5 14人 ,总感染率为 6 6 5 8% ;单因素分析 :不同地区 (χ2 =13 4 7,P <0 0 5 )、不同文化程度 (χ2 =7 36 ,P <0 0 5 )、不同婚姻状况 (χ2 =6 0 2 ,P <0 0 5 )甲肝病毒感染率有显著性差异。多因素分析 :吸毒人员中甲肝的感染与地区 ,文化程度 ,婚姻状况 ,与他人共用餐具等情况有关。结论　吸毒人群是甲型肝炎病毒感染的高危人群。甲型肝炎的影响因素有地区、文化程度、婚姻状况、与他人共用餐具等