Intrafamilial prevalence of hepatitis B virus in Western Brazilian Amazon region: epidemiologic and biomolecular study

Hepatitis B virus (HBV) serological patterns among the HBsAg negative hospital attendees screened for immunization

The Hepatitis B virus (HBV) is a highly infectious virus and is endemic in Uganda. It is one of the major etiological agents for liver diseases including liver cancer. In this work, we evaluated the prevalence of the HBV serological markers and the associated socio-demographic factors among hepatitis B surface antigen (HBsAg) seronegative persons screened during routine immunization against the virus in eastern Uganda. Data on the socio-demographic characteristics were collected using a structured questionnaire, while that on the serological markers were obtained from serum samples and evaluated by using the 5-panel HBV One Step Hepatitis B Virus Combo Test Device (Fastep^R, HBV-P43M). The following markers were evaluated by the panel: HBsAg, HBsAb, HBcAb, and HBeAb. Data were analyzed using SPSS (version 26), and multinomial logistic regression was used to elicit the adjusted odds ratio. All the analysis were performed at a 95% confidence limit, and a P value ≤ 0.05 was considered significant. The 424 participants included in this study were mainly female (62.3%), married (55.4%) and aged 30 years and above (54.2%). The seropositivity of the HBsAb, HBeAb, HBcAb marker prevalence rates was 48(11.3%), 73(17.2%) and 45(10.6%) respectively. The majority of the participants (327, 77.1%) did not present with any marker. Married paricipants were significantly associated with reduced HBsAb seropositvity rate, whereas young people aged 18–29 years were associated the with increased odds of HBsAb seropositivity (p < 0.05). Male participants were significantly associated with the HBeAb and HBcAb seropositivity (p < 0.05). Similarly, contact with an HBV infected person was significantly associated with HBeAb and HBcAb seropositivity (p < 0.05). Further still, blood transfusion was significantly associated with the increased risk of HBcAb seropositivity (P < 0.05). This study has revealed a prevalence of HBV serological markers among the HBsAg seronegative persons in this community and an increased risk of transmission of the virus in the community. Our findings have key consequences pertaining the interventions that are pertinent in the control and prevention of the spread of the virus among apparently health persons.

Hepatitis B virus genotypes and subgenotypes and the natural history and epidemiology of hepatitis B

INTRODUCTION AND OBJECTIVES

Espírito Santo state is considered a region with a higher frequency of hepatitis B virus infection. This study characterized demographic, epidemiological, laboratory, virological and clinical aspects of 587 chronic HBV carriers followed up at the University of Espírito Santo Hospital.

MATERIALS AND METHODS

Demographic, epidemiological, laboratory and clinical data were extracted from medical records during the entire follow-up period. Classification of the evolutionary phases of chronic hepatitis B was defined as immunotolerant; inactive carrier; chronic active hepatitis HBeAg (+)  and HBeAg (-). Characterization of HBV genotypes/subgenotypes was performed by sequencing of overlapping surface antigens and HBV DNA polymerase genes. Phylogenetic relationships were determined using BEAST 1.8.3 software.

RESULTS

and Conclusions: Genotypes found were A (132/65.3%) [A1 = 129 (63.9%) and A2 = 3 (1.5%)], D (66/32.7%) [D3 = 56 (27.7%), D4 = 8 (4.0%) and D2 = 2 (1.0%)] and F (4/2.0%) - all F2a. Subgenotypes A1 or D3 were not associated with age, sex, HIV/HCV co-infection, viral load, antiviral usage, HBeAg status or clinical stages of chronic hepatitis B. Mother -to-child-transmission (MTCT) was associated with the subgenotype A1 and intrafamilial transmission with subgenotype D3. Subgenotype A1 was more frequent than D3 among individuals born outside ES compared to those born in ES.

CONCLUSIONS

The most predominant clinical phases were HBeAg (-), inactive carrier and chronic active hepatitis HBeAg (-). Subgenotypes A1 and D3 were most frequent and were associated were MTCT and intrafamilial transmission of HBV, respectively.

Levels of hepatitis B antibody titers are affected by age and doses gap time in children from a high endemic area of the western Amazon

Background

Despite completion of the vaccine schedule for hepatitis B virus (HBV), children may display levels of HBV surface antibodies (anti-HBs) that are considered inadequate for sufficient protection (<10 IU/L).

Aims

Our aim was to investigate if age and gap time between HBV vaccine doses may negatively affect the levels of anti-HBs in children, and if these relationships are modified by sex.

Methods

In a high-endemic HBV region of the western Brazilian Amazon we enrolled children who had completed the HBV vaccine schedule. All children underwent analysis of anti-HBs and a clinical examination.

Results

We included 522 children (mean age 4.3 ± 0.8 years; 50% male). Median anti-HBs was 28.4 [interquartile range (IQR) 5.4 to 128.6] IU/L and 32% had anti-HBs <10 IU/L. The median gap time from last to preceding dose was 2.4 [IQR 2.1 to 3.3] months. Levels of anti-HBs decreased with higher age (-42% per year increase [95%CI -56% to -24%], p<0.001), but not with longer gap time (+23% per month increase [95%CI -16% to +62%], p = 0.249). After adjusting for relevant confounders, gap time became significant (p = 0.032) and age remained a significant predictor of anti-HBs (p<0.001).

Conclusion

One third of assessed children displayed anti-HBs <10 IU/L. Levels of anti-HBs decreased with higher age and increased with longer gap time between the last two doses.

Together let us confront it: An outbreak investigation of hepatitis B in Pathanamthitta district, Kerala

INTRODUCTION

Hepatitis B is a potentially life-threatening liver infection caused by the Hepatitis B virus (HBV). The established routes of transmission are from mother to infant, sexual contact, and exposure to blood or body fluids. Though HBV is preventable by vaccine and robust infection control practices, outbreaks of HBV infection do occur in India. However, the state of Kerala with its health parameters, one among the best in the country, cannot afford to have continuing outbreaks. An unusual increase in the reported cases of Hepatitis B in a rural area of Pathanamthitta district of Kerala, called for an outbreak investigation.

AIMS

To describe the epidemiological features, to determine the risk factors associated with HBV transmission, and to suggest measures to prevent future transmission.

METHODS

A community-based case-control study (1:2) was undertaken. A total of 162 participants (54 cases and 108 age, gender, and neighborhood matched controls) took part in the study. Focus group discussions were conducted with subject experts to develop an interview schedule assessing 40 risk factors. It was further reviewed by the University of Sydney. Data was collected by trained Junior Health Inspectors and Junior Public Health Nurses of the Primary Health Centers. Data was analyzed using SPSS v. 20. Proportions were compared by Univariate analysis, sub-group analysis, and logistic regression. Population Attributable Risk (PAR) was also calculated.

RESULTS AND CONCLUSION

More than 90% of the infections were IgM anti-HBc positive, suggesting a recent infection. Interventions during hospitalization [OR: 7.98 (95% CI - 2.17--29.4)], family history of Hepatitis B [OR. 4.14 (95%CI - 1.73--9.9)], and laboratory investigations [OR: 3.99 (1.72--9.31)] were found to be significant risk factors. PAR was highest for laboratory interventions (32%). Vaccinating household contacts and strict enforcement of infection control practices could substantially reduce the burden of this fatal disease.

A protocol of hepatic volume measurement using magnetic resonance imaging in individuals from the Eastern Brazilian Amazon population

Determination of hepatic volume is an important preoperative procedure and is done through imaging exams or standard liver volume (SLV) formulas developed based on the biotype of each population. In the absence of a specific SLV formula for the Brazilian Eastern Amazon population, the measurement of liver volume is made with reference values from other populations. The aim of study was to compare the hepatic volume in healthy residents from the Brazilian Eastern Amazon population obtained with magnetic resonance imaging (MRI) and recommended SLV formulas validated to other populations. This was a Observational, cross-sectional study. Anthropometric data of 42 healthy individuals aged 18–60 years of both sexes was collected to measure the liver volume through SLV formulas calculations and MRI. MRI shows similarity with the Western European SLV liver volume values and significant differences with the Japan SLV formula, mainly for women, with a moderate-to-weak correlation with the MRI measurements. There was a strong correlation between weight and body surface area in male patients analysed with measurements of the liver volume by the MRI and SLV formulas. The SLV formula based on the Western European population could be used in the absence of a specific formula for individuals living in the Amazon region. The results suggest that liver measurement formulas should take into consideration the sex of individuals, as well as the development of a specific SLV formula for the Eastern Amazon population and the conduction of similar studies in other Brazilian regions.

HBV epidemiology and genetic diversity in an area of high prevalence of hepatitis B in southern Brazil

Background

Hepatitis B virus (HBV) infection is a major public health problem in Brazil. HBV endemicity is usually moderate to low according to geographic regions, and high prevalence of this virus has been reported in people of some specific Brazilian counties, including those with a strong influence of Italian colonization in southern Brazil. Analysis of HBV diversity and identification of the main risk factors to HBV infection are necessary to understand hepatitis B epidemiology in these high prevalence regions in southern Brazil.

Objective

To investigate epidemiological characteristics and HBV genotypes and subgenotypes circulating in a specific city with high HBV prevalence.

Methods

A cross-sectional study was performed with 102 HBV chronically infected individuals, recruited in reference outpatient clinics for viral hepatitis in a city of high HBV prevalence (Bento Gonçalves) in Rio Grande do Sul state, Brazil between July and December 2010. Socio-demographic, clinical and behavior-related variables were collected in a structured questionnaire. HBV serological markers (HBsAg, anti-HBc), viral load, genotypes/subgenotypes and drug resistance were evaluated and comparatively analyzed among all patients.

Results

The HBV infected subjects had a mean age of 44.9 (±12.2) years, with 86 patients (84.3%) reporting to have a family history of HBV infection, 51 (50.0%) to share personal objects, and were predominantly of Italian descendants (61; 64.9%). There was a predominance of genotype D (49/54; 90.7%), but genotype A was also detected (5/54; 9.3%). Subgenotypes D1 (1; 4.7%), D2 (3; 14.3%), and D3 (17; 81.0%) were identified. LAM-resistant mutation (rtM204I) and ADV-resistant mutations (rtA181V) were detected in only one patient each.

Conclusions

These results demonstrate a pivotal role of intrafamilial transmission for HBV spreading in this population. Furthermore, there is a high prevalence of HBV genotype D in this region.

Risk factors for hepatitis B transmission in South Brazil

BACKGROUND

Hepatitis B virus (HBV) infection is a major public health problem in Brazil. Several risk factors are involved in HBV infection and their identification by a rational and essential approach is required to prevent the transmission of this infection in Brazil.

OBJECTIVES

To evaluate risk factors associated with HBV infection in South Brazil.

METHODS

A total of 260 patients with HBV and 260 controls from Caxias do Sul (state of Rio Grande do Sul, Brazil) participated in this study. All participants were given a standard questionnaire to yield the sociodemographic information and to identify HBV risk factors. HBV infection was detected by HBsAg test in all participants.

FINDINGS

HBV infection in these cases was strongly associated with history of a family member HBV-infected, mainly mother [odds ratio (OR) = 4.86; 95% confidence intervals (CI): 1.69-13.91], father (OR = 5.28; 95% CI: 1.58-17.71), and/or siblings (OR = 22.16; 95% CI: 9.39-52.25); sharing personal objects (OR = 1.40; 95% CI: 1.37-2.38); and having history of blood transfusion (OR = 2.05; 95% CI: 1.10-2.84).

CONCLUSIONS

HBV infection was strongly associated with having a family member infected with hepatitis B, sharing personal objects, and having history of blood transfusion.

Nationwide overview of the distribution of hepatitis B virus genotypes in Brazil: a 1000-sample multicentre study

The influence of hepatitis B virus (HBV) genotypes in the natural history of the disease and its response to antiviral treatment have been addressed in many studies. In Brazil, studies on HBV genotype circulation have been restricted to specific population groups and states. Here, we have conducted a nationwide multicentre study with an unprecedented sample size representing all Brazilian regions in an effort to better understand the viral variants of HBV circulating among chronic carriers. Seven HBV genotypes were found circulating in Brazil. Overall, HBV/A was the most prevalent, identified in 589 (58.7 %) samples, followed by HBV/D (23.4 %) and HBV/F (11.3 %). Genotypes E, G, C and B were found in a minor proportion. The distribution of the genotypes differed markedly from the north to the south of the country. While HBV/A was the most prevalent in the North (71.6 %) and Northeast (65.0 %) regions, HBV/D was found in 78.9 % of the specimens analysed in the South region. HBV/F was the second most prevalent genotype in the Northeast region (23.5 %). It was detected in low proportions (7 to 10 %) in the North, Central-West and Southeast regions, and in only one sample in the South region. HBV/E was detected in all regions except in the South, while monoinfection with HBV/G was found countrywide, with the exception of Central-West states. Our sampling covered 24 of the 26 Brazilian states and the Federal District and is the first report of genotype distribution in seven states. This nationwide study provides the most complete overview of HBV genotype distribution in Brazil to date and reflects the origin and plurality of the Brazilian population.

High prevalence of HBV/A1 subgenotype in native south Americans may be explained by recent economic developments in the Amazon

Native American populations present the highest prevalence of Hepatitis B Virus (HBV) infection in the Americas, which may be associated to severe disease outcomes. Ten HBV genotypes (A–J) have been described, displaying a remarkable geographic structure, which most likely reflects historic patterns of human migrations. In this study, we characterize the HBV strains circulating in a historical sample of Native South Americans to characterize the historical viral dynamics in this population. The sample consisted of 1070 individuals belonging to 38 populations collected between 1965 and 1997. Presence of HBV DNA was checked by quantitative real-time PCR, and determination of HBV genotypes and subgenotypes was performed through sequencing and phylogenetic analysis of a fragment including part of HBsAg and Pol coding regions (S/Pol). A Bayesian Skyline Plot analysis was performed to compare the viral population dynamics of HBV/A1 strains found in Native Americans and in the general Brazilian population. A total of 109 individuals were positive for HBV DNA (~ 10%), and 70 samples were successfully sequenced and genotyped. Subgenotype A1 (HBV/A1), related to African populations and the African slave trade, was the most prevalent (66–94%). The Skyline Plot analysis showed a marked population expansion of HBV/A1 in Native Americans occurring more recently (1945–1965) than in the general Brazilian population. Our results suggest that historic processes that contributed to formation of HBV/A1 circulating in Native American are related with more recent migratory waves towards the Amazon basin, which generated a different viral dynamics in this region.

Hepatitis B in Rondônia (Western amazon region, Brazil): descriptive analysis and spatial distribution

BACKGROUND

The Amazon is one of the regions who have the highest rates of infection by the hepatitis B virus in the world. Objectives This study aimed to evaluate the epidemiological data and spatial distribution of hepatitis B cases reported between 2002 and 2012 in the Brazilian State of Rondônia.

METHODS

Social and clinical data of these individuals were studied through the Information System for Notifiable Diseases (SINAN), including the following variables: gender, age group, vaccination, contact with a known patient with HBV, exposure to risk factors, source of infection, and clinical status.

RESULTS

There were 7,132 cases reported in Rondônia, with an average incidence rate of 42/100,000 inhabitants per year. The municipalities with the highest incidence rates were Monte Negro (187.6/100,000 inhabitants) and Ariquemes (157.2/100,000 inhabitants). The 20-39 year-old age group had the highest number of cases (n = 3,834), and 69.9% of patients were likely infected via sexual contact. Regarding the clinical disease status, most of the patients (80.7%) were in the chronic phase.

CONCLUSIONS

There was a recent 402% increase in the diagnosis of hepatitis B, which is likely owing to the improvements in the public diagnostic system. This highlights the need for public policies to prevent and control the disease.

Occurrence and spatial distribution of hepatitis C in a Western Brazilian Amazon state

CONTEXT

Hepatitis C causes a major impact on public health due to the high prevalence in the population.

OBJECTIVES

Evaluate the epidemiological data of hepatitis C in the State of Rondônia, Brazil.

METHODS

Data from hepatitis C were analyzed during the period 2002 to 2012, assigned by the Agency for Sanitary Vigilance of the State of Rondônia. The variables studied were: year of diagnosis, gender, age, associated disease, exposure to risk factors and clinical presentation.

RESULTS

Eight hundred fifty-nine cases were reported during the study period. Of this total, 542 (63.1%) cases were male. In relation to age group, the one with the highest number of cases was between 40-59 years (54%), followed by 20-39 years (33.5%). In relation to sexually transmitted diseases (STDs) association, 1.8% of patients had HIV and 2.1% other type of sexually transmitted disease. About exposure to risk factors, 288 (28.1%) individuals were exposed to a surgical procedure. Was also analyzed the clinical form of the disease, 9.9% are in acute disease and 91.1% in the chronic phase.

CONCLUSIONS

In the State of Rondônia, hepatitis C had a mean annual incidence of 5.1 cases/100,000 inhabitants, similar to the national rate.

Chronic HDV/HBV co-infection: predictors of disease stage---a case series of HDV-3 patients

BACKGROUND & AIMS

Chronic HDV/HBV co-infection is perhaps the most intriguing amongst all viral hepatitis. Only few studies focus deeply on this topic, particularly with patients infected with HDV-3. This study aimed to identify predictors of advanced disease, examining a cross-sectional data of 64 patients.

METHODS

Histological grading was used to characterize the disease stages and viral loads were tested as predictors of necroinflammatory activity and fibrosis.

RESULTS

We identified three HDV/HBV co-infection patterns: patients with predominant HDV replication (56.3%), patients with similar viral loads of both viruses (40.6%), and patients with predominant HBV replication (3.1%). Mean HDV-RNA showed a positive trend regarding inflammatory activity and grade of fibrosis. HDV viral load correlated positively with serum levels of liver enzymes and inversely with platelets count. HBV viral load showed no correlation with any of the above parameters. Advanced fibrosis was associated with age, splenomegaly, and HDV viral load of more than 2 log10. Multiple logistic regression confirmed the independent effect of HDV viral predominance. Advanced necroinflammatory activity was independently associated with HDV viral load and splenomegaly.

CONCLUSIONS

HDV may possibly play an important and direct role in the establishment of necroinflammatory activity and fibrosis. Data show an indigenous HDV genotype, HDV-3, similar to those described in the Amazon region.

Inactıve hepatitis B surface antigen carriers and intrafamilial tramsmission: results of a 10-year study

Background/Aims

The aims of the present study were to determine the outcomes of inactive hepatitis B virus (HBV) surface antigen (HBsAg) carriers over a 10-year study period and to elucidate the HBV serological profile of their family members.

Methods

We retrospectively analyzed the medical files of inactive HBsAg carriers followed up at the Department of Infectious Diseases of Kocatepe University Medical Faculty Hospital between March 2001 and January 2011.

Results

In total, 438 inactive HBsAg carriers were enrolled in this trial. The follow-up period was 33.7±22.5 months (mean±SD). Anti-hepatitis-B surface antibody seroconversion occurred in 0.7% of cases, while chronic hepatitis B was found in 0.5%. The anti-hepatitis-D virus (HDV) status was evaluated in 400 patients and anti-hepatitis C virus (HCV) in 430. It was found that 1% and 0.2% were positive for anti-HDV and anti-HCV, respectively. HBV serology was investigated in at least 1 family member of 334/438 (76.3%) patients. The HBsAg positivity rate was 34.6% in 625 family members of 334 patients. A comparison of the HBsAg positivity rates in terms of HBV DNA levels in index cases revealed that HBsAg seropositivity rates were higher in family members of HBV DNA-negative patients than in family members of HBV DNA-positive cases (P=0.0001).

Conclusions

The HBsAg positivity rate was higher in family members of inactive HBsAg carriers than in the general population; these family members therefore have a higher risk of HBV transmission. Furthermore, despite negative HBV DNA levels, transmission risk was not reduced in these patients, and horizontal transmission seems to be independent of the HBV DNA value.

Intrafamilial spread of hepatitis B virus in Guilan Province-North of Iran

The aim of the present study was to determine the intrafamilial spread of HBV in the family members of patients with Hepatitis B in Guilan Province, North of Iran. In a descriptive-comparative study, 156 patients with Hepatitis B, 415 family members of the index cases and 599 age and gender matched people as a control group were enrolled. Blood samples were taken from the participants and were checked for HBs Ag, HBC Ab, HBs Ab, and HBV DNA. Totally 44 (10.6%) of family members and only 1 (0.2%) of control group were HBs Ag positive (P=0.0001, OR=70.92). The overall prevalence in members of the original family was 5.3% (1.2% of the mothers, 2.2% of the brothers, 1.9% of the sisters), in sexual partners it was 1.4%, in offsprings it was 2.4% and in other households it was 1.4%. The mean age of HBs Ag positive family members was 35.3 ± 12.9 years old. Among them 27 (61.4%) were female. Only 8 (18.2%) of all HBsAg-positive reported previous HBV vaccination but just one person had the vaccine titer checked. The present survey indicates that there is a significant difference in the prevalence of Hepatitis B in the general population and family members of Hepatitis B patients and this is an evidence for horizontal transmission of HBV in household contacts.

Seroprevalence and risk factors of hepatitis B and hepatitis C virus infections in uttarakhand, India

BACKGROUND AND AIMS

Hepatitis B virus (HBV) and hepatitis C virus (HCV) infections are a serious global public health problem affecting billions of people. A population based serological survey was conducted in Uttarakhand, India to determine the prevalence and risk factors of HBV and HCV infections.

METHODS

A cross-sectional study was conducted to achieve the primary objective of estimating the prevalence of HBsAg and anti-HCV seropositivity and to estimate the potential risk factors.

RESULTS

A total of 495 volunteers completed the study questionnaire and underwent blood tests for HBsAg and anti-HCV serology. Of these, 339 (68.5%) were males and 156 (31.5%) were females. The mean age of the volunteers was 31 ± 4 years. The overall infection rate was 4.4% (n = 22) in the studied population. The seroprevalence of HBsAg was found to be 2.8% (n = 14) and of anti-HCV antibodies 1.8% (n = 9), whereas dual infection i.e. HBV and HCV infection was seen in 0.2% (n = 1). The overall analysis of risk factors of our data showed that persons who have received multiple blood transfusions, history of hepatitis among family members, visits to unregistered medical practitioners and uneducated people are at more risk for acquiring hepatitis B and hepatitis C infection.

CONCLUSIONS

The results indicate an intermediate level of endemicity of HBV and HCV infection in this geographical area of Uttarakhand. Some independent risk factors like blood transfusion, intra familial transmission, and visit to unregistered practitioners were identified.

Intra-familial Transmission of Hepatitis B virus Infection in Zahedan

BACKGROUND

The household transmission of hepatitis B virus (HBV) is a major health problem. The prevalence rate of this infection is reported about 11% to 57% among family members of HBsAg carriers.

OBJECTIVES

This study was conducted to evaluate serological determinants of chronic hepatitis B infection, especially HBsAg positivity, among family members of asymptomatic HBsAg positive carriers in Zahedan (Southeast of Iran).

PATIENTS AND METHODS

In a cross-sectional study, data were collected from the total number of 454 HBsAg positive cases and 1817 members of their family by trained interviewers and a validated questionnaire. In addition, blood samples were obtained and titrated to detect serologic markers of hepatitis B. All subjects were recruited following informed consent to the study.

RESULTS

In total, 454 chronic HBsAg carriers (66% male) with mean age of 36 ± 10 years and 1817 of their family members were included in the study. The prevalence rate of HBsAg and HBcAb positivity among household members were 19.3% (n = 351) and 51% (n = 573), respectively. The frequency of HBV markers was different by age groups. The highest prevalence rate of HBsAg (34.9%) and HBcAb (31.9%) positivity were found in the age group of 21-30 years old. Importantly, the mothers of index cases had the highest prevalence of HBsAg positivity compared to their spouses who had the lowest proportion (53.2% vs. 8.4%, P < 0.001).

CONCLUSIONS

In family members, HBsAg positivity was four times greater than the general indigenous population. Considering the importance of close contacts for transmission, it was more prevalent in mothers of index cases compared to their spouses, suggesting more efficient mother-to-child than sexually transmission of HBV. It was also more prevalent in those having a history of hepatitis B in their maternal family compared to those with paternal one, probably due to more efficient transmission from infected mothers to children. The lower prevalence of HBsAg positivity in lower age groups could be attributed to vaccination of Iranian infants since 1993 and the screening of HBsAg positive mothers during the last two decades.

Molecular epidemiology of hepatitis B virus among the indigenous population of the Curuçá and Itaquaí Rivers, Javari Valley, State of Amazonas, Brazil

INTRODUCTION

Hepatitis B virus (HBV) infection is one of the most serious public health problems in the world. In Brazil, HBV endemicity is heterogeneous, with the highest disease prevalence in the North region.

METHODS

A total of 180 samples were analyzed and subjected to polymerase chain reaction (PCR) and semi-nested PCR of the HBV S-gene, with the aim of determining the prevalence of HBV-DNA (deoxyribonucleic acid) in indigenous groups inhabiting the areas near the Curuçá and Itaquaí Rivers in the Javari Valley, State of Amazonas, Brazil.

RESULTS

The prevalence of the HBV-DNA S-gene was 51.1% (92/180). The analysis found 18 of 49 (36.7%) samples from the Marubo tribe, 68 of 125 (54.4%) from the Kanamary, and 6 of 6 (100%) from other ethnic groups to be PCR positive. There was no statistically significant difference in gender at 5% (p=0.889). Indigenous people with positive PCR for HBV-DNA had a lower median age (p<0.001) of 23 years. There was no statistical difference found in relation to sources of contamination or clinical aspects with the PCR results, except for fever (p<0.001). The high prevalence of HBV-DNA of 75% (15/20) in pregnant women (p=0.009) demonstrates an association with vertical transmission.

CONCLUSIONS

The results confirm the high prevalence of HBV-DNA in the Javari Valley, making it important to devise strategies for control and more effective prevention in combating the spread of HBV.

Epidemiology and molecular characterization of hepatitis B virus infection in isolated villages in the Western Brazilian Amazon

Individuals from three isolated, rural communities in the western Brazilian Amazon were evaluated for serological markers of hepatitis B virus (HBV) infection, HBV genotype, and the presence of risk factors for infection and transmission. Of the 225 individuals studied, 79.1% had serological evidence of HBV infection; 10.2% individuals were chronic carriers for HBV surface antigen (HBsAg-positive). Analysis of risk factors indicates that HBV is transmitted mainly horizontally within the family from a chronic "active" carrier for hepatitis B "e" antigen (HBeAg-positive), though a strong possibility of vertical transmission remains. The predominance of HBV genotype F, with a higher genomic similarity between the isolates, indicated a relatively recent introduction of HBV, from a common source, to the area. This study sheds light on the HBV epidemiology in the Brazilian Amazon region and highlights the need for greater emphasis on HBV control and immunization programs.

Deficient knowledge on hepatitis B infection in pregnant women and prevalence of hepatitis B surface antigen carriage in an endemic area: a review

Hepatitis B infection is a major global health problem. Vertical transmission is the commonest route of spreading hepatitis B virus (HBV) in many endemic areas. In order to control such transmission in Hong Kong, neonatal immunization programme was implemented for more than two decades. A declining prevalence of HBV infection was expected. However, the prevalence remained unabated at around 10% in recent studies. We suspect that one of the explanations of this persistent high prevalence is deficient knowledge on infection with the HBV and its prevention. Our paper gives an overview of the knowledge on HBV infection among Chinese population in both high and low endemic areas and discusses the potential factors that influenced the knowledge on as well as the implication of the sources of information for HBV infection, which was not addressed in previous studies.

Clinical, demographic and epidemiological characteristics of patients with hepatitis B followed at a university hospital in southeastern Brazil: predominance of HBeAg negative cases

INTRODUCTION

Hepatitis B is common in Brazil, although there are regional differences regarding the degree of endemicity, the most frequent forms of transmission and the presence of different evolutive stages of chronic disease. The present study aimed to determine the clinical, demographic and epidemiological characteristics of patients chronically infected with hepatitis B virus (HBV) residing in the Ribeirão Preto region, southeastern Brazil.

METHODS

A total of 529 medical records of individuals with HBV monoinfection were reviewed.

RESULTS

More than 60% of the subjects were males, with a mean age of 38 years-old. The HBeAg-negative serological pattern was verified in 84.4% of the patients, among whom the risk of vertical/intrafamily transmission was 43.2% (p = 0.02). The consumption of alcohol in amounts exceeding 20 g a day was observed in 21.3% of the subjects and was more frequent among men (33%) (p < 0.001). Among patients with cirrhosis, 54.1% were alcohol abusers (p = 0.04), all of them males. The presence of cirrhosis was more frequent in the HBeAg-positive group (24.4%) than in the HBeAg-negative group (10.2%) (p < 0.001).

CONCLUSIONS

High proportions of HBV-infected subjects with an HBeAg-negative pattern were observed, with a higher risk of vertical/intrafamily transmission. Alcohol abuse was associated with male subjects and with cirrhosis of the liver in this group. A tendency toward an increase in the number of HBeAg-negative cases was observed over time.

The prevalence of HBV infection in the cohort of IDPs of war against terrorism in Malakand Division of Northern Pakistan

BACKGROUND

Hepatitis B is an important public health problem in the Pakistani population and is the major cause of chronic hepatitis, cirrhosis, fibrosis and hepatocellular carcinoma. High prevalence of HBV infections has been observed especially in areas of low economic status. In spite of effective immunization programs, no significant change has been observed in the epidemiology of HBV in the rural areas of Pakistan (~67.5% of the total population) mainly due to lack of interest from government authorities and poor hygienic measures. The current study was aimed at estimating the prevalence and risk factors associated with HBV infection within internally displaced persons (IDPs) due to war against terrorism in the Malakand Division of Northern Pakistan.

METHODS

Blood samples from 950 IDPs suspected with HBV infection (including both males and females) were collected and processed with commercial ELISA kits for HBsAg, Anti HBs, HBeAg, Anti HBe antibodies. The samples positive by ELISA were confirmed for HBV DNA by real-time PCR analysis.

RESULTS

The overall prevalence of HBV observed was 21.05% of which 78.5% were males and 21.5% were females. Most confirmed HBV patients belong to the Malakand and Dir (lower) district. High-risk of infection was found in the older subjects 29.13% (46-60 years), while a lower incidence (11.97%) was observed in children aged <15 years. Lack of awareness, socioecomic conditions, sexual activities and sharing of razor blades, syringes and tattooing needles were the most common risk factors of HBV infection observed during the cohort of patients.

CONCLUSION

The present study, revealed for the first time a high degree of prevalence of HBV infection in rural areas of Northern Pakistan. The noticed prevalence is gender- and age-dependent that might be due to their high exposures to the common risk factors. To avoid the transmission of HBV infection proper awareness about the possible risk factors and extension of immunization to the rural areas are recommended.

Hepatitis B genotype G and high frequency of lamivudine-resistance mutations among human immunodeficiency virus/hepatitis B virus co-infected patients in Brazil

In this study, we evaluated the hepatitis B virus (HBV) genotype distribution and HBV genomic mutations among a group of human immunodeficiency virus-HBV co-infected patients from an AIDS outpatient clinic in São Paulo. HBV serological markers were detected by commercially available enzyme immunoassay kits. HBV DNA was detected using in-house nested polymerase chain reaction and quantified by Cobas Amplicor. HBV genotypes and mutations in the basal core promoter (BCP)/pre-core/core regions and surface/polymerase genes were determined by sequencing. Among the 59 patients included in this study, 55 reported prior use of lamivudine (LAM) or tenofovir. HBV DNA was detected in 16/22 patients, with a genotype distribution of A (n = 12,75%), G (n = 2,13%), D (n = 1,6%) and F (n = 1,6%). The sequence data of the two patients infected with genotype G strongly suggested co-infection with genotype A. In 10 patients with viremia, LAM-resistance mutations in the polymerase gene (rtL180M + rtM204V and rtV173L + rtL180M + rtM204V) were found, accompanied by changes in the envelope gene (sI195M, sW196L and sI195M/sE164D). Mutations in the BCP and pre-core regions were identified in four patients. In conclusion, genotype G, which is rarely seen in Brazil, was observed in the group of patients included in our study. A high prevalence of mutations associated with LAM-resistance and mutations associated with anti-HBs resistance were also found among these patients.

High frequency of lamivudine resistance mutations in Brazilian patients co-infected with HIV and hepatitis B

This study analyzed the genotype distribution and frequency of lamivudine (LAM) and tenofovir (TDF) resistance mutations in a group of patients co-infected with HIV and hepatitis B virus (HBV). A cross-sectional study of 847 patients with HIV was conducted. Patients provided blood samples for HBsAg detection. The load of HBV was determined using an "in-house" real-time polymerase chain reaction. HBV genotypes/subgenotypes, antiviral resistance, basal core promoter (BCP), and precore mutations were detected by DNA sequencing. Twenty-eight patients with co-infection were identified. The distribution of HBV genotypes among these patients was A (n = 9; 50%), D (n = 4; 22.2%), G (n = 3; 16.7%), and F (n = 2; 11.1%). Eighteen patients were treated with LAM and six patients were treated with LAM plus TDF. The length of exposure to LAM and TDF varied from 4 to 216 months. LAM resistance substitutions (rtL180M + rtM204V) were detected in 10 (50%) of the 20 patients with viremia. This pattern and an accompanying rtV173L mutation was found in four patients. Three patients with the triple polymerase substitution pattern (rtV173L + rtL180M + rtM204V) had associated changes in the envelope gene (sE164D + sI195M). Mutations in the BCP region (A1762T, G1764A) and in the precore region (G1896A, G1899A) were also found. No putative TDF resistance substitution was detected. The data suggest that prolonged LAM use is associated with the emergence of particular changes in the HBV genome, including substitutions that may elicit a vaccine escape phenotype. No putative TDF resistance change was detected after prolonged use of TDF.

[Hepatitis B vaccination: a major player in the control of primary liver cancer]

In worst cases, chronic hepatitis B ultimately leads to primary liver cancer. Populations the more at risk to develop hepatocellular carcinoma (HCC), i.e. patients infected perinatally, reside essentially in Asia. A quarter of century after its introduction in medical practice, data coming from Eastern Asia demonstrate a strong impact of the vaccine on HCC incidence. Strikingly, universal immunization of Taiwanese newborns reduced fourfold pediatric HCC incidence. However, residual cases still appear though among children infected at birth by HBe antigen-carrying mothers. Epidemiologic models indicate that the continuation of universal vaccination policy will reduce chronic hepatitis B endemicity 50-fold in three generations. Recently, mutant forms of HBV potentially escaping to vaccine appeared as a potential consequence of large-scale vaccination. Finally, lack of early immunization of newborns in developing countries still represents a major limitation to the progresses against liver cancer.

Hepatitis B and hepatitis C in Pakistan: prevalence and risk factors

BACKGROUND

Pakistan carries one of the world's highest burdens of chronic hepatitis and mortality due to liver failure and hepatocellular carcinomas. However, national level estimates of the prevalence of and risk factors for hepatitis B and hepatitis C are currently not available.

METHODS

We reviewed the medical and public health literature over a 13-year period (January 1994-September 2007) to estimate the prevalence of active hepatitis B and chronic hepatitis C in Pakistan, analyzing data separately for the general and high-risk populations and for each of the four provinces. We included 84 publications with 139 studies (42 studies had two or more sub-studies).

RESULTS

Methodological differences in studies made it inappropriate to conduct a formal meta-analysis to determine accurate national prevalence estimates, but we estimated the likely range of prevalence in different population sub-groups. A weighted average of hepatitis B antigen prevalence in pediatric populations was 2.4% (range 1.7-5.5%) and for hepatitis C antibody was 2.1% (range 0.4-5.4%). A weighted average of hepatitis B antigen prevalence among healthy adults (blood donors and non-donors) was 2.4% (range 1.4-11.0%) and for hepatitis C antibody was 3.0% (range 0.3-31.9%). Rates in the high-risk subgroups were far higher.

CONCLUSIONS

Data suggest a moderate to high prevalence of hepatitis B and hepatitis C in different areas of Pakistan. The published literature on the modes of transmission of hepatitis B and hepatitis C in Pakistan implicate contaminated needle use in medical care and drug abuse and unsafe blood and blood product transfusion as the major causal factors.

Intra-familial spread of hepatitis B virus infection in eastern Turkey

Hepatitis B virus (HBV) infection is a worldwide health problem. The aim of the present study was not only to determine the prevalence of HBsAg in children of HBV-infected parents but also to identify all HBSAg-positive family members to protect as many children, in the present and future, as possible. The study was carried out with the participation of 2113 family members (1205 children, 453 mothers, and 455 fathers) at Sivas SSK Hospital, Turkey. They were screened for HBV markers using standard enzyme immunoassay between September 2001 and March 2005. The prevalence of any HBV markers and HBsAg among family members of index cases was 50.5% and 30.5% respectively. HBsAg carrier rate was higher among fathers (61%) than mothers (47%), (P<0.05). The children of mother index cases had higher rates of HBsAg compared with the children of father index cases (P<0.01). Our results suggest that intra-familial childhood horizontal transmission (especially mother-to-child) is important for HBV transmission in the Turkish community, and highlights the need for screening of adult siblings and mothers of adult HBsAg carriers in addition to their spouses and children.