[Hepatitis A and hepatitis B seroprevalence in 4 centers in Brazil]

Sociodemographic and spatiotemporal profiles of hepatitis-A in the state of Pará, Brazil, based on reported notified cases

Hepatitis-A virus is a worldwide healthcare problem, mainly affecting countries with poor sanitary and socioeconomic conditions. This communication evaluates the spatiotemporal variability of the disease's socioepidemiological profile in one of the endemic Brazilian regions (Pará State) prior to (2008-2013) and after (2014-2017) the launch of the national public vaccination programme. Hepatitis-A epidemiological reports concerning Pará State - Brazil - were used for this study including municipalitylevel data of the disease's reported positive notification cases (PNCs). The analyses involved socioepidemiological profiling and space-time scan statistics. A total of 5500 PNCs were reported in the study period. On average, PNCs decreased over time throughout the state, with strongest drops after 2015. The PNCs were specific for gender, race/ethnic origin and age group. The predominant gender and race/ethnic groups was male and brown, respectively. While children were the most susceptible age group prior to 2015, there was a shift towards older ages (young and adults) in later years. Those found to be the most affected by the disease, as shown by space-time scan statistics, were people in densely populated municipalities with unsatisfactory sanitary conditions and also less well covered by the public vaccination programme. Despite drops in the number of hepatitis-A PNCs, thanks to the national vaccination programme, the disease still persists in Pará State and elsewhere in Brazil. The present study reinforces the need of continuous prevention and control strategies for effective control and erradication of hepatitis-A.

Associations Between Environmental and Sociodemographic Data and Hepatitis-A Transmission in Pará State (Brazil)

Hepatitis-A is a waterborne infectious disease transmitted by the eponymous hepatitis-A virus (HAV). Due to the disease's sociodemographic and environmental characteristics, this study applied public census and remote sensing data to assess risk factors for hepatitis-A transmission. Municipality-level data were obtained for the state of Pará, Brazil. Generalized linear and nonlinear models were evaluated as alternative predictors for hepatitis-A transmission in Pará. The Histogram Gradient Boost (HGB) regression model was deemed the best choice ( R M S E = 2.36, and higherR 2  = 0.95) among the tested models. Partial dependence analysis and permutation feature importance analysis were used to investigate the partial dependence and the relative importance values of the independent variables in the disease transmission prediction model. Results indicated a complex relationship between the disease transmission and the sociodemographic and environmental characteristics of the study area. Population size, lack of sanitation, urban clustering, year of notification, insufficient public vaccination programs, household proximity to open-air dumpsites and storm-drains, and lack of access to healthcare facilities and hospitals were sociodemographic parameters related to HAV transmission. Turbidity and precipitation were the environmental parameters closest related to disease transmission. Based on HGB model, a hepatitis-A risk map was built for Pará state. The obtained risk map can be thought of as an auxiliary tool for public health strategies. This study reinforces the need to incorporate remote sensing data in epidemiological modelling and surveillance plans for the development of early prevention strategies for hepatitis-A.

Prevalence of hepatitis A in the capitals of the States of North, Southeast and South regions of Brazil: decrease in prevalence and some consequences

Hepatitis A virus (HAV) infection has been considered one of the leading causes of acute hepatitis. The aim of the present study was to estimate the prevalence of HAV among children and adolescents in a population-based study in the capitals of the States of the North, Southeast and South of Brazil and identify predictive factors for the infection. A multi-stage sampling was used to select subjects aged between 5-9 and 10-19 years. Individual and household levels aside from the level of variables in the areas were collected. The outcome was the total IgG antibodies to HAV levels detected using a commercial Enzyme Immuno Assay (EIA). The associations between HAV and the independent variables were assessed using the odds ratio. A multilevel analysis was performed by GLLAMM using the Stata software. The prevalence of HAV infection in the 5-9 and 10-19 age groups was 28.7% and 67.5%, respectively for the North, 20.6% and 37.7%, for the Southeast and 18.9% and 34.5% for the South Region. The prevalence of HAV increased according to age in all sites. Variables related to education at the individual level (North and South), family and area level (South and Southeast) and family income level (Southeast and South) were independently associated with HAV infection. This emphasizes the need for individualized strategies to prevent the infection.

Hepatitis A seroprevalence in public school children in Campos dos Goytacazes, Rio de Janeiro State, Brazil, prior to the introduction of the hepatitis A universal childhood vaccination

This cross-sectional study was carried out between August 2011 and July 2012 in the city of Campos dos Goytacazes in Rio de Janeiro State, Brazil. Dried blood spot samples were collected on filter paper from 919 individuals between the ages of 1 and 19 and were tested for antibodies against the hepatitis A virus (anti-HAV). The total prevalence was 20.7%, while 94.7% of children under the age of 5 were found to be susceptible to HAV infection. The prevalence of anti-HAV increased with age, reaching 33.3% among individuals aged between 15 and 19, thereby indicating that this municipality has a low level of endemicity for hepatitis A. Age, non-white skin color, accustomed to swimming in the river and more than five people living at home were the factors that were associated with an increase in the chance of a positive anti-HAV result. Mother's education level (secondary or tertiary) was considered a protective factor for HAV infection. The data obtained showed that a large proportion of the children from Campos dos Goytacazes were at risk of HAV infection, which should be minimized with the introduction of the vaccination program against hepatitis A that was launched in the municipality in 2011.

Epidemiological, serological and molecular aspects of hepatitis B and C in children and teenagers of municipal daycare facilities schools and schools in the city of Santos

OBJECTIVE

To estimate the prevalence of the serological markers anti-HBc, HBsAg and anti-HBs of hepatitis B and anti-HCV of hepatitis C among children and teenagers enrolled at daycare facilities, kindergartens and municipal elementary education network in the city of Santos, São Paulo, Brazil.

METHODS

A cross-sectional study was carried out from June 28 to December 14, 2007, in which 4,680 finger-prick blood samples were collected from children and teenagers. A survey questionnaire was applied to their family members. The sample was dimensioned using the software Epi Info version 6 with expected frequency of 1%, acceptable error of 0.5% and confidence interval of 95%. The serological tests were performed using the ELISA technique. The molecular analysis was performed using the technique of polymerase chain reaction in House.

RESULTS

Age of the studied population ranged from 7 months to 18 years and 1 month. The general prevalence of anti-HBc reagent was 0.1%, HBsAg was 0.02% and anti-HCV was 0.02%.

CONCLUSIONS

In children, the general prevalence of serological markers for hepatitis B and C in the city of Santos was low when compared with literature data.

Epidemiology of hepatitis B virus in the cities of the northern region of Espírito Santo, Brazil

The World Health Organization (WHO) estimates that approximately 2 billion people worldwide have already had contact with hepatitis B virus (HBV) and 373 million have become chronic carriers. Hepatitis B is a major cause of chronic hepatitis, cirrhosis and hepatocellular carcinoma, leading to a large number of deaths annually. Both viral factors and the host immune response have been implicated in the pathogenesis and clinical result of HBV infection. Many Brazilian cities, including the cities of the northern region of the state of Espírito Santo are located in regions with little health infrastructure. Our study performed an epidemiological analysis of cases of Hepatitis B in São Mateus, using methodology of Geographic Information System (GIS), aiming to raise the number of disease cases, establishing preventive measures to control the disease, improving the quality of life of people affected by this pathology. The city of São Mateus had the largest number of reported cases of hepatitis B northern region of Espírito Santo. The age group with the highest number of hepatitis B notifications was 20-49 years, mostly females. The major forms of contact with HBV in these cities were dental treatment, use of injectable medications, surgical procedures and multiple sexual partners.

Socioeconomic inequities and hepatitis A virus infection in Western Brazilian Amazonian children: spatial distribution and associated factors

BACKGROUND

Hepatitis A is still a neglected health problem in the world. The most affected areas are the ones with disadvantaged socioeconomic conditions. In Brazil, seroprevalence studies showed that 64.7 % of the general population has antibodies against HAV (hepatitis A virus), and the Amazon region has the highest seroprevalence in the country.

METHODS

In the present study the seroprevalence of total HAV antibodies in children between 1 and 5 years old residing in the urban area of Assis Brasil, Acre was measured and spatial distribution of several socioeconomic inequities was evaluated.

RESULTS

In the year of 2011, seroprevalence rate was 16.66 %. Factors associated with having a positive serology identified by multivariate analysis were being of indigenous ethnicity [adjusted Odds Ratio (aOR) = 3.27, CI 1.45-7.28], usage of water from the public system (aOR = 8.18, CI 1.07-62.53), living in a house not located in a street (aOR = 3.48, CI 1.54-7.87), and child age over 4 years old (aOR = 2.43, CI 1.23-4.79). The distribution of seropositive children was clustered in the eastern part of the city, where several socioeconomic inequities (lack of flushed toilets, lack of piped water inside the household and susceptibility of the household to flooding during rain, low maternal education, having wood or ground floor at home, and not owning a house, lack of piped water at home, and type of drinking water) also clustered.

CONCLUSIONS

The findings highlight that sanitation and water treatment still need improvement in the Brazilian Amazon, and that socioeconomic development is warranted in order to decrease this and other infectious diseases.

Hepatitis A seroprevalence in preschool children in Assis Brazil, Acre, Brazil, in 2003 and 2010

BACKGROUND

The Amazon region has the highest seroprevalence of hepatitis A virus (HAV) in Brazil.

METHODS

In the present study, the seroprevalence of total HAV antibodies in two groups, composed of 147 and 254 children between 1 and 5 years old in Assis Brasil, Acre, was measured in 2003 and 2010, respectively, and compared with socio-economic changes in the city.

RESULTS

In 2003, the HAV seroprevalence rate was 26.5%, while in 2010, it was 22.4%. There was an overall improvement in socio-economic and sanitary conditions, with the exception of open sewage. In 2003, factors associated with positive serology were child age (aOR [adjusted odds ratio] 1.84; 95% CI: 1.28-2.64), having a latrine or not having a toilet at home (aOR 4.73; 95% CI: 1.06-21.17) and the treatment of drinking water with chlorine (aOR 0.26; 95% CI: 0.07-0.92). In 2010, the main factors associated with positive serology were using rivers, streams and rainwater as sources of water for domestic purposes (aOR 24.36; 95% CI: 3.69-160.85); having a wooden or ground floor at home (OR 2.51; 95% CI: 1.11-5.69) and child age (aOR 2.33; 95% CI: 1.66-3.28).

CONCLUSIONS

In the Brazilian Amazon, sanitation and water treatment still require improvement and socio-economic development is warranted in order to decrease hepatitis A transmission.

Cross-Sectional Study of Hepatitis A Virus Infection in the Pantanal Population before Vaccine Implementation in Brazil: Usage of Non-Invasive Specimen Collection

Population-based prevalence studies are essential tools for screening of hepatitis A and provide important data on susceptible groups. However, surveillance in isolated communities is difficult because of the limited access to these areas and the need for blood sample collection. This study aimed to determine the anti-HAV prevalence using oral fluid samples to provide an alternative tool for epidemiological studies that might be useful for vaccination-related decisions. The study population was composed of 224 volunteers from South Pantanal, aged 3 to 86 years old. This study was performed using oral fluids, previously standardized for anti-HAV antibody detection, which were collected using a ChemBio device. Eluates were tested using modified commercial EIA to detect anti-HAV antibodies. The overall prevalence was 79.1%, corresponding to 178 reactive EIA tests out of 224 samples. The age stratified data revealed a prevalence of 47.8% between 0–10 years, 84% in 11–20 years and 91.9% in subjects older than 21 years. Results indicate that hepatitis A prevalence was higher in adolescents and adults, corroborating the literature reports. Thus, oral fluid samples could replace serum in HAV epidemiological studies in isolated communities as they are efficient at detecting anti-HAV antibodies.

Hepatitis A and E seroprevalence and associated risk factors: a community-based cross-sectional survey in rural Amazonia

BACKGROUND

Hepatitis A virus (HAV) and hepatitis E virus (HEV) are both transmitted by the faecal-oral route, and represent common causes of acute hepatitis in developing countries. The endemicity of HAV infection has shifted from high to moderate in Brazil. Human cases of HEV infection seem to be rare, although the virus has been detected in swine livestock and effluents of slaughterhouses. This study was to determine the epidemiology of hepatitis A and E in one of the largest agricultural settlements in the Amazon Basin of Brazil.

METHODS

Serum samples collected from 397 individuals aged between 5 and 90 years during a population-based cross-sectional survey were tested for anti-HAV and anti-HEV antibodies. Associated risk factors and spatial clustering of HAV and HEV seropositivity were also analyzed.

RESULTS

The overall rate of HAV seropositivity was 82.9% (95% confidence interval (CI), 79.2-86.6%). Multilevel logistic regression analysis identified increasing age (in years; odds ratio (OR), 1.097; 95% CI, 1.050-1.147; P < 0.001) and crowding (OR, 1.603; 95% CI, 1.054-2.440; P = 0.028) as significant risk factors for HAV seropositivity. Anti-HEV IgG was detected in 50/388 settlers (12.9%, 95% CI, 9.5-16.2%). Anti-HEV IgM was detected in 7/43 (16.3%) anti-IgG positive samples, and 4 of them had a confirmed result by immunoblot. Increasing age was the only significant determinant of HEV seropositivity (OR, 1.033; 95% CI, 1.016-1.050; P < 0.001). No significant spatial clustering of HAV and HEV seropositivity was detected in the area.

CONCLUSIONS

Both HAV and HEV are endemic, with differing rates of infection in children and adults in this rural setting of the Brazilian Amazon. Anti-HEV prevalence was considerably higher than those previously reported in Brazil. The detection of HEV- specific IgM antibodies in four asymptomatic individuals is highly suggestive of the circulation of HEV in this rural population.

Modelling the force of infection for hepatitis A in an urban population-based survey: a comparison of transmission patterns in Brazilian macro-regions

Background

This study aimed to identify the transmission pattern of hepatitis A (HA) infection based on a primary dataset from the Brazilian National Hepatitis Survey in a pre-vaccination context. The national survey conducted in urban areas disclosed two epidemiological scenarios with low and intermediate HA endemicity.

Methods

A catalytic model of HA transmission was built based on a national seroprevalence survey (2005 to 2009). The seroprevalence data from 7,062 individuals aged 5–69 years from all the Brazilian macro-regions were included. We built up three models: fully homogeneous mixing model, with constant contact pattern; the highly assortative model and the highly assortative model with the additional component accounting for contacts with infected food/water. Curves of prevalence, force of infection (FOI) and the number of new infections with 99% confidence intervals (CIs) were compared between the intermediate (North, Northeast, Midwest and Federal District) and low (South and Southeast) endemicity areas. A contour plot was also constructed.

Results

The anti- HAV IgG seroprevalence was 68.8% (95% CI, 64.8%–72.5%) and 33.7% (95% CI, 32.4%–35.1%) for the intermediate and low endemicity areas, respectively, according to the field data analysis. The models showed that a higher force of infection was identified in the 10- to 19-year-old age cohort (∼9,000 infected individuals per year per 100,000 susceptible persons) in the intermediate endemicity area, whereas a higher force of infection occurred in the 15- to 29-year-old age cohort (∼6,000 infected individuals per year per 100,000 susceptible persons) for the other macro-regions.

Conclusion

Our findings support the shift of Brazil toward intermediate and low endemicity levels with the shift of the risk of infection to older age groups. These estimates of HA force of infection stratified by age and endemicity levels are useful information to characterize the pre-vaccination scenario in Brazil.

Sex bias in infectious disease epidemiology: patterns and processes

BACKGROUND

Infectious disease incidence is often male-biased. Two main hypotheses have been proposed to explain this observation. The physiological hypothesis (PH) emphasizes differences in sex hormones and genetic architecture, while the behavioral hypothesis (BH) stresses gender-related differences in exposure. Surprisingly, the population-level predictions of these hypotheses are yet to be thoroughly tested in humans.

METHODS AND FINDINGS

For ten major pathogens, we tested PH and BH predictions about incidence and exposure-prevalence patterns. Compulsory-notification records (Brazil, 2006-2009) were used to estimate age-stratified ♂:♀ incidence rate ratios for the general population and across selected sociological contrasts. Exposure-prevalence odds ratios were derived from 82 published surveys. We estimated summary effect-size measures using random-effects models; our analyses encompass ∼0.5 million cases of disease or exposure. We found that, after puberty, disease incidence is male-biased in cutaneous and visceral leishmaniasis, schistosomiasis, pulmonary tuberculosis, leptospirosis, meningococcal meningitis, and hepatitis A. Severe dengue is female-biased, and no clear pattern is evident for typhoid fever. In leprosy, milder tuberculoid forms are female-biased, whereas more severe lepromatous forms are male-biased. For most diseases, male bias emerges also during infancy, when behavior is unbiased but sex steroid levels transiently rise. Behavioral factors likely modulate male-female differences in some diseases (the leishmaniases, tuberculosis, leptospirosis, or schistosomiasis) and age classes; however, average exposure-prevalence is significantly sex-biased only for Schistosoma and Leptospira.

CONCLUSIONS

Our results closely match some key PH predictions and contradict some crucial BH predictions, suggesting that gender-specific behavior plays an overall secondary role in generating sex bias. Physiological differences, including the crosstalk between sex hormones and immune effectors, thus emerge as the main candidate drivers of gender differences in infectious disease susceptibility.

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.

[Hepatitis B mortality in Brazil, 2000-2009]

This descriptive study focused on the mortality profile associated with hepatitis B virus (HBV) in Brazil as a whole and by region, based on data from the Mortality Information System (MIS). The study sample consisted of deaths from HBV recorded in the MIS from January 1, 2000, to December 31, 2009. The crude mortality rate remained constant in the country; the proportion of hepatocellular carcinoma with HBV as the associated cause was no greater than 7%. The standardized mortality rate was highest in the North of Brazil, and the proportional mortality rate was higher in males. In 2009, the potential years of life lost (PYLL) were highest in males in the 50-59-year age bracket and in females in the 40-49-year bracket. The largest increase in PYLL occurred in males 60 to 69 years of age. The study emphasizes the importance of scaling up preventive measures against HBV, in addition to expanding access to early diagnosis in order to reduce HBV mortality in the coming decades.

Epidemiological and serological aspects of hepatitis A among children and teenagers in the city of Santos: a cross-sectional study

CONTEXT AND OBJECTIVE

Viral hepatitis A is still a concern at public health level in Brazil and around the world, due both to the number of affected subjects and the possibility of complications in the acute forms. The Brazilian Ministry of Health estimates that at least 70% of this country's population has already had contact with the hepatitis A virus (HAV). The aim here was to discover the prevalence of serological markers for the hepatitis A virus among children and teenagers at daycare facilities, kindergartens and elementary schools in the city of Santos.

DESIGN AND SETTING

Cross-sectional study in kindergartens and elementary schools within the municipal education network in several regions of the city of Santos.

METHOD

Students' family members were surveyed using a questionnaire and 4,680 finger-prick blood samples were taken and assayed by means of the ELISA technique.

RESULTS

The general prevalence of anti-HAV IgG was 9.72% and, of these cases, 74.6% were reactive to anti-HAV IgM. There was higher prevalence of anti-HAV IgG among older children, females, children who played in streams, those whose homes were not connected to the sewage system, those whose parents had low education levels, those with low household income and those who did not live along the seashore. The prevalence of anti-HAV IgM peaked in the early years and subsequently fell, and it was lower on the hills and in the Northwestern Zone.

CONCLUSION

The general prevalence of serological markers for hepatitis A was low in Santos.

Seroprevalence of hepatitis A immunity among brazilian adult patients with liver cirrhosis: is HAV vaccination necessary?

BACKGROUND

Patients with chronic liver disease have a higher risk of fulminant hepatitis when infected with hepatitis A virus, and vaccination of these patients against such infection is recommended. In Brazil, mainly in the South and Southeast regions, the epidemiology of hepatitis A (HA) has shifted from high to intermediate endemicity, which would have implication on policy of HA vaccination for these populations.

OBJECTIVE

To verify the prevalence of HA immunity in adult patients with liver cirrhosis (LC), in Uberlândia MG, a city of Southeastern Brazil.

METHODS

Between December 2005 and December 2006, 106 patients with LC were consecutively evaluated. In addition, 75 individuals without LC or alcoholism were evaluated (control group - CG).

RESULTS

Total anti-HAV (ELISA methods) was positive in 104 (98.1%) patients with LC (82 men, 24 women; mean age, 53.3 ± 11.9 years) and in 74 (98.7%) individuals of the CG (55 men, 20 women; mean age, 47 ± 11.6 years), p > 0.05.

CONCLUSIONS

For patients with chronic liver disease, in the geographic regions and age groups evaluated, routine vaccination against hepatitis A is not recommended. Moreover, the serum determination of total anti-HAV, used to assess immunity, is five times cheaper than vaccination against hepatitis A and, for this reason, should precede vaccination.

Soroprevalência de anticorpos contra vírus herpes simples 1-2 no Brasil

OBJETIVO: Estimar a soroprevalência de anticorpos por vírus herpes simples (HSV-1 e HSV-2) e analisar fatores associados no Brasil. MÉTODOS: Estudo transversal realizado entre 1996 e 1997 em 1.090 indivíduos com idade entre um e 40 anos da população geral, em quatro diferentes regiões geográficas no Brasil. Foram analisadas amostras sangüíneas para detecção de anticorpos para HSV-1 e HSV-2 com teste tipo-específico Elisa. Foram descritas freqüências e proporções, comparadas entre grupos utilizando o teste de Fisher bilateral exato. Foi realizada análise de regressão logística para avaliar influência das variáveis sociodemográficas e histórico de DST, sobre a soroprevalência de HSV-1 e/ou HSV-2. RESULTADOS: As soroprevalências de anticorpos para HSV-1 e HSV-2, ajustadas por idade, foram 67,2% e 11,3% respectivamente, sem diferença quanto ao sexo e maiores na Região Norte. As soroprevalências aumentaram com a idade, e para HSV-2 o maior aumento ocorreu na adolescência e entre adultos jovens. Indivíduos soropositivos para HSV-1 apresentaram maior risco de serem positivos para HSV-2 (15,7%) quando comparados com os negativos para HSV-1 (4,7%). Na análise multivariada, o histórico de DST aumentou significativamente (OR=3,2) a probabilidade de soropositividade para HSV-2. CONCLUSÕES: As soroprevalências para HSV-1 e para HSV-2 variam com a idade e entre as regiões do Brasil. História pregressa de DST é importante fator de risco para aquisição de infecção por HSV-2.

Hepatic stellate cell activation and hepatic fibrosis in children with type 1 autoimmune hepatitis: an immunohistochemical study of paired liver biopsies before treatment and after clinical remission

OBJECTIVES

The activation of hepatic stellate cells (HSC) is considered the most important event in hepatic fibrogenesis. The precise mechanism of this process is unknown in autoimmune hepatitis (AIH), and more evidence is needed on the evolution of fibrosis. The aim of this study was to assess these aspects in children with type 1 AIH.

METHODS

We analyzed 16 liver biopsy samples from eight patients, paired before treatment and after clinical remission, performed an immunohistochemical study with anti-alpha actin smooth muscle antibody and graded fibrosis and inflammation on a scale of 0-4 (Batts and Ludwig scoring system).

RESULTS

There was no significant reduction in fibrosis scores after 24+/-18 months (2.5+/-0.93 vs. 2.0+/-0.53, P=0.2012). There was an important decrease in inflammation: portal (2.6+/-0.74 vs. 1.3+/-0.89, P=0.0277), periportal/periseptal (3.0+/-0.76 vs. 1.4+/-1.06, P=0.0277), and lobular (2.8+/-1.04 vs. 0.9+/-0.99, P=0.0179). Anti-alpha actin smooth muscle antibodies were expressed in the HSC of the initial biopsies (3491.93+/-2051.48 mum), showing a significant reduction after remission (377.91+/-439.47 microm) (P=0.0117).

CONCLUSION

HSC activation was demonstrated in the AIH of children. The reduction of this activation after clinical remission, which may precede a decrease in fibrosis, opens important perspectives in the follow-up of AIH.

[Knowledge of obstetricians about the vertical transmission of hepatitis B virus]

CONTEXT

Vertical transmission is responsible for 35%-40% of the new cases of hepatitis B worldwide and it is associated with an increased risk of chronic hepatitis B, cirrhosis and hepatocellular carcinoma.

OBJECTIVE

To describe obstetricians' knowledge on the recommended measures to the diagnosis of the infection by the hepatitis virus B in pregnant women and to prevent the transmission of this infection to the babies of infected mothers.

METHODS

Obstetricians registered at the 'Sociedade de Ginecologia e Obstetrícia da Bahia', Salvador, BA, Brazil were randomly selected and invited to answer a questionnaire with questions regarding their academic formation, workplace, contact with medical students and their practices about the hepatitis virus B. Individuals who were not currently working as obstetricians or were not living in the state of Bahia were excluded from the study. Data were analyzed with the EpiInfo software with a 95% confidence interval.

RESULTS

Three hundred and one obstetricians answered the questionnaire: 90.3% of them recognized that the hepatitis virus B could be transmitted vertically and 81.7% routinely screened their patients for hepatitis virus B infection during prenatal consultations; 66.0% considered HBsAg the best serological marker to be employed on the screening. Only 13.0% systematically recommended the vaccination against hepatitis virus B and the administration of immunoglobulin to the newborns of infected mothers in the first 12 hours of life. The frequency of correct answers about the vertical transmission of hepatitis virus B, the best serological marker for screening and the management of infected mothers and their newborns was higher among professionals who had the 'Título de Especialista em Ginecologia e Obstetrícia (TEGO)' than among the remaining ones (P = 0.018, P = 0.001 and P = 0.002, respectively).

CONCLUSION

We observed that the knowledge of the obstetricians about the diagnosis and management of hepatitis virus B infection during pregnancy is not adequate, reinforcing the need of continuous medical education programs on the infections that can be transmitted vertically.

Prevalence of hepatitis A virus infection: the paradoxical example of isolated communities in the western Brazilian Amazon region

This study evaluated the prevalence of hepatitis A virus infection in the rural area of Lábrea, in the western Brazilian Amazon region. Communities and households were selected randomly. Serum samples were analyzed by means of the immunoenzymatic method for the presence of total antibodies against HAV. The study included 1,499 individuals. The prevalence of anti-HAV was 74.6% (95% CI 72.3-76.8). Univariate analysis showed associations with age (chi-square for linear trend = 496.003, p < 0.001), presence of outside toilet (p < 0.001), history of hepatitis (p < 0.001) and family history of hepatitis (p = 0.05). After adjusting for age, HAV infection also showed an association with the number of people in the family (p = 0.03). The overall prevalence rates were high, but not more than 60% of the children under the age of ten years had already been infected. Very high prevalence was detected only within older cohorts, thus paradoxically defining this as a region with intermediate endemicity, even under the conditions of poverty encountered.

Should Brazilian patients with chronic hepatitis C virus infection be vaccinated against hepatitis A virus?

BACKGROUND AND AIM

Hepatitis A virus (HAV) superinfection is associated with a high risk of liver failure and death in patients with hepatitis C virus (HCV) infection. The aim of this study was to investigate the presence of serological and molecular HAV markers in a population of HCV-infected patients in order to determine a cost-effective strategy to vaccinate against HAV.

METHODS

The presence of total and immunoglobulin (Ig)M anti-HAV antibodies was investigated in 399 patients (median age, 50 years; range, 4-81) referred to the Public Health Central Laboratory of Pernambuco State who tested positive for anti-HCV antibodies and HCV RNA. HAV RNA was investigated by reverse transcription-nested polymerase chain reaction in these patients.

RESULTS

Three hundred and eighty-four (96%) patients were positive for anti-HAV total and negative for IgM anti-HAV antibodies (immune patients). Three patients had IgM (and total) anti-HAV antibodies, showing an acute infection, and two of them had HAV RNA detected in serum samples. HAV RNA was also found in another patient in the absence of detectable anti-HAV antibodies. By nucleotide sequencing, it was demonstrated that the HAV isolates infecting these patients belonged to subgenotype 1B.

CONCLUSION

This study provides valuable new data on anti-HAV prevalence among HCV carriers in Brazil. In the present study, we found a high proportion of patients with anti-HAV positivity, indicating that anti-HAV testing of HCV-infected patients is a cost-effective strategy and should be carried out before vaccination against HAV in these patients, particularly in regions such as our geographical area with high total anti-HAV prevalence.

Marcadores sorológicos do vírus da hepatite B em mulheres jovens atendidas pelo Programa de Saúde da Família em Vitória, Estado do Espírito Santo, 2006

O objetivo deste estudo foi determinar a freqüência dos marcadores sorológicos para hepatite B e de fatores de risco associados com a infecção pelo vírus B em mulheres jovens, residentes em Vitória, ES, onde a vacinação em recém-nascidos e em adolescentes foi iniciada em 1994 e 2000, respectivamente. Estudo populacional, por amostragem, realizado em três regiões de saúde de Vitória em 2006. Foi realizada entrevista e pesquisa de HBsAg, anti-HBc e anti-HBs. De 1.200 mulheres selecionadas, 1.029 (85,7%) participaram do estudo. A mediana de idade foi 23 anos (distância interquartil 20-26 anos) e 93,2% tinham mais de quatro anos de escolaridade. Quarenta e três (4,2%) mulheres (IC95% 2,97%-5,43%)] apresentaram anti-HBc total positivo e 9 (0,9%) (IC95% 0,4%-1,6%)] HBsAg. Houve 466 (45,3%) testes (IC95% 42,2%-48,4%)] anti-HBs positivos dos quais 427 eram anti-HBc e HBsAg negativas. A única variável independentemente associada com anti-HBc (+) foi renda mensal de até 4 salários mínimos [OR =2,6 (IC95% 1,06-6,29)]. Os dados mostram baixa prevalência do vírus B e de seus fatores de risco mais conhecidos. A prevalência do anti-HBs com anti-HBC e HBsAg negativos reflete a cobertura vacinal do Município neste grupo (43,7%). Não foi possível determinar fatores de risco significativos para a aquisição do vírus hepatite B nessa população.

Changing epidemiology of hepatitis A in Brazil: reassessing immunization policy

Recent studies have shown that the prevalence of antibody to hepatitis A virus (HAV) is decreasing in several Latin American countries. Brazil is a very large and heterogeneous country, showing striking regional differences. With regard to sanitary facilities, 81.7% of the districts in the south-eastern region have sewage systems, compared with only 5.8% in the northern region. Results of sero-epidemiological studies and reported hepatitis A outbreaks indicate a change in the epidemiological pattern of hepatitis A in the country. Individuals, especially those under the age of 10, are mostly unprotected from HAV infection, regardless of their socioeconomic status. During 2000-2005, approximately 14 000-21 000 cases of hepatitis A were reported annually in Brazil, a rate of 7.5-11 cases per 100 000 population. Nationwide, hepatitis A mortality rates declined progressively from 1980 to 2002. As fatal cases constitute a small, but predictable, portion of all acute hepatitis A cases, which are in turn part of the total number of HAV infections, these data suggest that there has been a decline in HAV circulation in all Brazilian regions over the last two decades. Taken together these facts point out that the epidemiological pattern of hepatitis A is changing in Brazil. Besides improvements in sanitary conditions in the poorest Brazilian regions, the introduction of hepatitis A vaccination of young children could be a strategy for controlling HAV infection in the country.

Hepatitis A acute liver failure: follow-up of paediatric patients in southern Brazil

We retrospectively analysed 33 children and adolescents who had been hospitalized in a liver transplant unit within the previous 10 years for acute liver failure (ALF). The patients' age varied between 2 months and 15 years of age (median 6.2 +/- 5.3), and 21 (63%) were male. Thirteen patients (39%) were immunoglobulin-M anti-hepatitis A virus (HAV) sero-positive. Eleven cases (33%) had an undetermined aetiology. The 13 children with HAV ALF were between 17 months and 15.6 years of age (median 5.8 +/- 4.6) and eight were male (61.5%). All were on a list for urgent liver transplant. Of these, five (38%) died while waiting for a liver. Only one patient recovered spontaneously. Seven patients received a liver transplant; three died in the immediate postoperative period and one died 45 days after transplant. Three children are alive 1, 2 and 5 years after transplant. We conclude that HAV was the most frequent cause of ALF, which had high mortality even when a liver transplant was possible. The results support universal HAV vaccination in this area.

A population-based survey of the prevalence of HIV, syphilis, hepatitis B and hepatitis C infections, and associated risk factors among young women in Vitória, Brazil

OBJECTIVE

To estimate the prevalence of HIV, hepatitis B (HBV) and C (HCV), and syphilis infections and associated risk exposures in a population-based sample of young women in Vitória, Brazil.

METHODS

From March to December 2006, a cross-sectional sample of women aged 18-29 years was recruited into a single stage, population-based study. Serological markers of HIV, HBV, HCV, and syphilis infections and associated risk exposures were assessed.

RESULTS

Of 1,200 eligible women, 1,029 (85.8%) enrolled. Median age was 23 (interquartile range 20-26) years; 32.2% had < or = 8 years of education. The survey weighted prevalence estimates were: HIV, 0.6% [(95% CI), 0.1%, 1.1%]; anti-HBc, 4.2% (3.0%, 5.4%); HBsAg, 0.9% (0.4%, 1.6%); anti-HCV, 0.6% (0.1%, 1.1%), and syphilis 1.2% (0.5%, 1.9%). Overall, 6.1% had at least one positive serological marker for any of the tested infections. A majority (87.9%) was sexually active, of whom 12.1% reported a previously diagnosed sexually transmitted infection (STI) and 1.4% a history of commercial sex work. Variables independently associated with any positive serological test included: older age (> or = 25 vs. < 25 years), low monthly income (< or = 4x vs. > 4x minimum wage), previously diagnosed STI, > or = 1 sexual partner, and any illicit drug use.

CONCLUSIONS

These are the first population-based estimates of the prevalence of exposure to these infectious diseases and related risks in young women, a population for whom there is a scarcity of data in Brazil.

[Prevalence of hepatitis B and D serological markers in the Parakanã, Apyterewa Indian Reservation, Pará State, Brazil]

In order to study the prevalence of hepatitis B (HBV) and D (HDV) viruses in the Parakanã Indians and to evaluate the impact of hepatitis B vaccination beginning there in 1995, 258 serum samples were analyzed in the year 2004 for hepatitis B and D serological markers using immunoenzymatic techniques; the results showed a moderate endemic pattern, with a total prevalence of HBV infection of 55.7% and 5.4% of virus carriers in the Apyterewa village and 49.5% with 1.1% of HBV carriers in the Xingu village; 31.4% of anti-HBs+ as an isolated marker in both villages and no detection of positive serological tests for HDV among HBV carriers. The laboratory analysis thus showed the presence of chronic HBV carriers, absence of HDV carriers, and an emerging vaccine profile among susceptibles, confirming the effectiveness and need to maintain vaccination, especially in the first year of life, and the need to implement effective epidemiological surveillance for early detection of HDV infection among HBV carriers.

Residual infectious disease risk in screened blood transfusion from a high-prevalence population: Santa Catarina, Brazil

BACKGROUND

Infectious disease testing has improved but viral infection transmission through transfusion continues to occur. Residual risk, however, is now so low in some countries that it can only be estimated by mathematical modeling. With hierarchical Bayesian methods, this study estimates the residual risk of transfusion-transmitted infections in Santa Catarina, Brazil.

STUDY DESIGN AND METHODS

Data from the six state blood collection services covering Santa Catarina between 1998 and 2002 were used. Information was obtained on donor profiles, screening and confirmatory test results, and records of all allogeneic blood donations for repeat donors. Residual risk estimates of hepatitis B virus (HBV), human immunodeficiency virus (HIV), hepatitis C virus (HCV), and human T-cell leukemia virus (HTLV) were separately derived from posterior distributions of incidence rates and preseroconversion window-period lengths.

RESULTS

Estimated risks of a donation infectious for HBV and HIV entering the blood supply are 1:10,700 (95% confidence interval [CI], 1:4900-1:28,200) and 1:26,200 (95% CI, 1:14,800-1:64,100) donations, respectively. Estimated risks for HCV and HTLV were 1:19,300 (95% CI, 1:10,400-1:44,800) and 1:116,300 (95% CI, 1:40,200-1:1,000,000) donations, respectively. HBV risk is 1.8 times greater than HCV risk, 2.4 times greater than HIV risk, and 10.8 times that of HTLV. Actual risks would be lower due to immune recipients and subinfectious levels of undetected viremia.

CONCLUSION

The major factor contributing to risk differences between Santa Catarina and countries with similar testing regimes is the much higher source population diseases prevalence. Payoff for nucleic acid testing would be low, thus additional investment in safety should be based on studies of the cost-effectiveness of different strategies to reduce overall transmission.

Análise de fatores associados à não aceitação da vacina contra hepatite B em adolescentes escolares de baixa renda

Para avaliar os fatores de predição da não adesão à vacina contra o vírus da hepatite B (VHB) em adolescentes escolares de baixa renda da Região Metropolitana de Goiânia, Goiás, 304 indivíduos suscetíveis ao VHB, matriculados em duas escolas, foram entrevistados e a vacina contra hepatite foi oferecida. Somente 195 (64%) adolescentes aceitaram a primeira dose da vacina. Por outro lado, 182/195 (93,3%) receberam o esquema completo. Verificou-se que fatores escolares exerceram um papel na aceitação da vacina, uma vez que a escola B e turno noturno foram independentemente associados à não adesão à vacina. Os achados deste estudo ratificam a baixa aceitação da vacina contra hepatite B em adolescentes e evidenciam a necessidade de programas de educação em saúde para sensibilização desse grupo em relação à vacinação, e reforçam a importância de estratégias de imunização na escola para o cumprimento do esquema completo da vacina contra o VHB nesta população-alvo.

Molecular epidemiology of hepatitis A virus in Brazilian Amazon

BACKGROUND

Hepatitis A virus (HAV) is highly endemic in the Amazon. However, few data are available regarding HAV genotypes circulating in this region of the world. The aim of the present study was to characterize genetically HAV isolates circulating in the Brazilian part of the Amazon.

METHODS

Blood samples were collected from 134 IgM anti-HAV positive patients (sporadic cases). Viral RNA was extracted and the virion protein (VP)1/2A junction region of the HAV genome was successfully amplified by reverse transcription-polymerase chain reaction for 81 samples (60.4%). Nucleotide sequences (210 bp) of the 81 isolates were determined.

RESULTS

All HAV samples were from genotype I, with 78 (96.3%) belonging to subgenotype IA and three (3.7%) to subgenotype IB. By phylogenetic analysis, it was shown that 72/78 of the subgenotype IA isolates formed a cluster separated from the other South American HAV isolates previously characterized.

CONCLUSION

The present study provides valuable new data on the genetic relatedness of HAV from the Amazon. Subgenotype IB circulates in the Brazilian Amazon but the predominant genotype is 1A, similar to what occurs in most South American countries.

Prevalence of serological markers of hepatitis B virus in pregnant women from Paraná State, Brazil

The prevalence of hepatitis B virus (HBV) in Brazil increases from South to North but moderate to elevated prevalence has been detected in the Southwest of Paraná State. The prevalence of serological markers of HBV was evaluated in 3188 pregnant women from different counties in Paraná State and relevant epidemiological features were described. The prevalence of HBV markers in pregnant women for the state as a whole was 18.5% (95% CI = 17.2-19.9), ranging from 7.2% in Curitiba to 38.5% in Francisco Beltrão. The endemicity of HBV marker prevalence in pregnant women was intermediate in Cascavel, Foz do Iguaçu, and Francisco Beltrão, and low in Curitiba, Londrina, Maringá, and Paranaguá. Multiple logistic regression showed that HBV marker prevalence increased with age, was higher among black women, among women of Italian and German descent, and among women who had family members in neighboring Rio Grande do Sul State. Univariate analysis showed that HBV marker prevalence was also higher among women with no education or only primary education, with a lower family income and whose families originated from the South Region of Brazil. Pregnant women not having positive HBV markers (anti-HBc, HBsAg or anti-HBs detected by ELISA) corresponded to 73.7% of the population studied, implying that HBV vaccination needs to be reinforced in Paraná State. The highest prevalence was found in three counties that received the largest number of families from Santa Catarina and Rio Grande do Sul, where most immigrants were of German or Italian ascendance. This finding probably indicates that immigrants that came to this area brought HBV infection to Southwestern Paraná State.

Seroepidemiology of hepatitis B virus infection and high rate of response to hepatitis B virus Butang®vaccine in adolescents from low income families in Central Brazil

In order to evaluate the seroepidemiology and response to Butang vaccine in adolescents from low income families in Central Brazil, blood samples of 664 adolescents were tested for hepatitis B surface antigen (HBsAg), hepatitis B core antibody (anti-HBc), and hepatitis B surface antibody (anti-HBs) markers, and multiple logistical regression analysis was carried out to determine variables associated with hepatitis B virus (HBV) infection markers. further, three 20 microg Butang vaccine doses were offered to all susceptible individuals (n = 304). Among those who accepted them (n = 182), the seroresponse was evaluated in 170 individuals by quantitative anti-HBs. an overall hbv prevalence of 5.9% was found: four adolescents were HBsAg positive, 24 were anti-HBc, anti-HBs-reactive, and 11 were anti-HBc only. The analyse of risk factors showed that age 16-19 years, place of birth outside Goiás, school B and body piercing were statistically associated with HBV infection markers (p < 0.05). All 170 adolescents responded to Butang, and a geometric mean titer (gmt) of 4344 mUI/ml was obtained. these results reinforce the importance of hepatitis b vaccine in adolescents despite of the hbv regional endemicity, and suggest that three doses of 20 microg of the Butang should guarantee protective anti-hbs levels to individuals at a critical time for hepatitis b acquiring such as latter adolescence and adulthood.

Anti-hepatitis A virus frequency in adolescents at an outpatient clinic in São Paulo, Brazil

The prevalence of hepatitis A virus (HAV) antibodies was assessed in adolescents (age ranging from 10.4 to 19.9 years) at an Adolescent Outpatient Clinic in São Paulo, Brazil. Anti-HAV was detected in 137 (54.2%) out of 253 individuals. When separated into two age groups, anti-HAV frequency was higher in the 15 to 19 year-old group (64%) in comparison to the 10 to 14 year-old group (46%) (Chi-square test: p = 0.004). These results suggest that adolescents in São Paulo are at risk of hepatitis A infection and are probably contracting HAV infection during this age period.

Epidemiology of hepatitis A and E virus infection in Brazil

This review has the objective to discuss the epidemiological aspects of the enterically transmitted hepatitis A and E in Brazil. The prevalence of hepatitis A varies greatly in different Brazilian regions, from 56% in South and Southeast to 93% in North region (Manaus, Amazon). Such differences are also found in different socioeconomic levels among age groups. A significantly higher prevalence was seen in the low socioeconomic group between 1-30 years. This difference is most striking in the first 10 years of age (23.5% vs 60.0%, high/middle vs low, respectively). Despite the improvements in sanitary conditions, hepatitis A is still endemic and outbreaks may occur. As an increasing proportion of the population is becoming susceptible to hepatitis A virus infection and as adult individuals may present more severe forms of the disease, the authors conclude that the implement of hepatitis A vaccination should be considered. Some Brazilian data have shown that the genotype found in our country were IA and IB. Isolates from this study were closely related genetically (or even identical) to isolates originating in other South American countries and overseas, providing firm evidence for epidemiological links between persons who travel to endemic areas. In spite of favorable environmental conditions, outbreaks of hepatitis E have never been reported in Brazil. Nevertheless, reports have demonstrated the evidence of anti-hepatitis E virus antibodies in some Brazilian regions. The seroprevalence of IgG anti-hepatitis E virus among normal populations shows positivities of 6.1% in gold-miners, 3.3% in general population, 2.0-7.5% in blood donors, 1.0% in pregnant women, and 4.5% in children, with no differences among regions. In populations at risk the prevalence of anti-hepatits E virus varies greatly. Among patients with acute non-A, non-B, non-C hepatitis 2.1% was detected in the Southeast to 29% in the Northeast, in 10.6% of acute non-A, non-B, non-C hepatitis relatives in the Amazon basin, in 12% of acute sporadic non-A non-B hepatitis patients in the Northeast, a co-infection with acute hepatitis A in 25 to 38% in the Northeast, in 14 to 18% among prostitutes and women considered at risk for human immunodeficiency virus in the Southeast, and in 12% of the intravenous drug users in the Southeast.

Experiments with mathematical models to simulate hepatitis A population dynamics under different levels of endemicity

Heterogeneous access to sanitation services is a characteristic of communities in Brazil. This heterogeneity leads to different patterns of hepatitis A endemicity: areas with low infection rates have higher probability of outbreaks, and areas with higher infection rates have high prevalence and low risk of outbreaks. Here we develop a mathematical model to study the effect of variable exposure to infection on the epidemiological dynamics of hepatitis A. Differential equations were used to simulate population dynamics and were numerically solved using the software Stella. The model uses parameters from serological surveys in the Greater Metropolitan Rio de Janeiro, in areas with different sanitation conditions. Computer simulation experiments show that the range of infection rates observed in these communities are characteristic of high and low levels of hepatitis A endemicity. We also found that the functional relationship between sanitation and exposure to infection is an important component of the model. The analysis of the public health impact of partial sanitation requires a better understanding of this relationship.

Prevalence of anti-hepatits A antibodies in children of different socioeconomic conditions in Vila Velha, ES

This report describes the prevalence of anti-HAV antibodies in children from elementary school in the Municipality of Vila Velha, ES, Brazil. Anti-HAV antibodies were investigated by ELISA method in the serum of 606 children (four to fourteen years old) from three elementary schools, located in neighborhoods with varying household monthly income levels: São José School, 200 children, household income higher than US$700; São Torquato School, 273 children, US$200 to 300; and Cobi School, 133 children, less than US$200. From each children data on age, gender, skin color, sanitary conditions, frequency of contact with sea or river water and family history of hepatitis were recorded. Anti-HAV antibodies were present in 38.6% of all children, 9% in São José School, 49.1% in São Torquato School and 61.7% in Cobi School. Logistic regression analysis demonstrated a positive correlation of positive anti-HAV test with age, non white color of the skin, absence of sewage treatment and domestic water filter, and a past history of hepatitis. The prevalence of anti-HAV antibodies in school children in Vila Velha, ES, was lower than that observed in the same age group in North and Northeast Brazil and was significantly higher in children from families with low socioeconomic status. In addition the results indicate a changing epidemiologic pattern of hepatitis A in our country, with an increasing number of children and adolescents with high risk for HAV infection, mainly in high socioeconomic class. A consideration must be given to the feasibility of vaccination programs for children and adolescents in our country.

The effects of socioeconomic development on worldwide hepatitis A virus seroprevalence patterns

BACKGROUND

Hepatitis A virus (HAV) infection confers long-term immunity, so mathematical analysis of age-specific seroprevalence in populations can reveal changes in the infection rate over time. HAV transmission is related to access to clean drinking water, personal hygiene and public sanitation.

METHODS

We used an SIR (susceptible-infectious-recovered) compartmental model with age structure to fit a time-dependent logistic function for HAV force of infection for 157 published age-seroprevalence data sets. We then fit linear regression models for socioeconomic variables and infection rate.

RESULTS

The proportion of the population with access to clean drinking water, the value of the human development index (HDI), and per capita gross domestic product (GDP) are all inverse predictors of HAV infection rates. Declining infection rates were observed in 65.6% of the surveys. Discussion This work demonstrates the utility of HAV seroprevalence studies to reveal patterns of change in force of infection and to assess the association between socioeconomic risk factors and transmission rates.

Hepatitis B vaccine efficacy in patients with chronic liver disease by hepatitis C virus

BACKGROUND

Considering the immunosuppression of patients with chronic liver disease, their response to vaccination is discussed in literature.

AIMS

To evaluate the response of hepatitis B vaccine in patients with chronic hepatitis C virus infection.

METHODS

This is a prospective study in which 85 patients with chronic hepatitis C virus infection (46.8 +/- 9.4 years, 44.7% males) and 46 healthy adults (36.7 +/- 11.1 years; 39.1% males) were evaluated. Confirmation of hepatitis C virus was obtained by the technique of polymerase chain reaction. Viral load was determined by the branched DNA method in 74 patients, and genotype was determined by sequencing in 73 patients. All patients and healthy adults received three doses of Engerix B vaccine IM (at 0, 30 and 180 days). Serological responses to the vaccine were divided into three categories: seroprotection, when anti-HBs was > or =100 mUI/mL; seroconversion, when anti-HBs was 10-99 mUI/mL, and non-reagent, when anti-HBs was <10 mUI/mL.

RESULTS

The response of hepatitis B vaccine as determined 1 month following dose 3 was seroprotection in 37.7%, seroconversion in 17.6% and non-reagent in 44.7% among patients and 84.8%, 13.0%, 2.2%, respectively in healthy adults. The number of non-reagent responses was significantly higher among those patients with chronic liver disease. Sixty-five patients with chronic hepatitis were compared to 20 compensated cirrhotic patients in concern to the response to vaccine, but no difference was found. The response to vaccine in patients with genotypes 2 or 3 (n = 40) was better than in those with genotype 1 (n = 33). Response was not related to serum HCV-RNA concentration.

CONCLUSION

The number of non-responders was higher in patients with chronic hepatitis C virus infection, irrespective of histological status and viral load. It is suggested that such patients should receive a double dose of vaccine, particularly the ones with genotype 1.

Infecção pelo vírus da hepatite C na região Amazônica brasileira

O artigo avalia informações científicas disponíveis sobre a prevalência e características clínicas da infecção pelo virus da hepatite C na Amazônia Brasileira, uma área sabidamente endêmica para infecção pelos vírus das hepatites A, B e D. Toda a informação foi obtida através de extensa revisão bibliográfica de artigos originais e de revisão e de resumos publicados em periódicos conceituados ou em eventos científicos. Na Região Amazônica, a taxa de prevalência de infecção por VHC na população geral varia de 1,1 a 2,4%. Entre doadores de sangue as taxas de prevalência variam de 0,8% a 5,9%. O Estado do Pará (Amazônia oriental) e do Acre (Amazônia ocidental) apresentam as maiores taxas, 2% e 5,9%, respectivamente. Com relação à prevalência da infecção pelo VHC em grupos de risco, observa-se alta prevalência entre hemodiálisados (48,1% - 51,9%), profissionais de saúde (3,2%), contactantes de portadores do VHC (10%) e pacientes com lichen plannus (7,5%). Existe uma predominância significativa do genótipo 1, com maior freqüência do subtipo 1b. A infecção pelo VHC é similar em homens e mulheres e a maioria dos infectados têm mais de 39 anos de idade. A principal via de infecção é a parenteral e os principais fatores de risco são transfusão sangüínea e procedimentos cirúrgicos. O VHC raramente é responsável por hepatite aguda grave nesta região. Por outro lado, de todas as hepatites crônicas, 22,6% são atribuídas ao VHC na Amazônia Ocidental e 25% na Amazônia Oriental. Na Amazônia Brasileira, a infecção pelo VHC parece ter o mesmo comportamento da infecção em outras partes do mundo.

Infecção pelo vírus da hepatite A em área indígena da Amazônia oriental brasileira

A hepatite viral A representa importante problema de saúde pública em todo o mundo, estando relacionada às condições sócioeconômicas e de higiene da população. Na Amazônia brasileira, estudos soroepidemiológicos em populações indígenas tem demonstrado alta endemicidade relacionada à infecção. Objetivando avaliar a prevalência da infecção pelo vírus da hepatite A em aldeia xicrin, no município de Altamira-Pará-Brasil, cuja investigação foi desencadeada por óbito de criança indígena, que evoluiu clinicamente em nove dias, com quadro ictero-hemorrágico, sem realização de exame sorológico, foram analisadas 352 amostras de sangue através de testes sorológicos dos marcadores virais das hepatites A, B, C e D, por técnica imunoenzimática, que indicaram uma prevalência de 98% de anticorpos contra a hepatite A e destes, 30,5% com infecção recente, caracterizando em base laboratorial, o surto de infecção pelo vírus da hepatite A e levantando a possibilidade de estar associado com o óbito ocorrido na aldeia.

[Hepatitis A]

Hepatitis A infection is known since the ancient Chinese, Greek and Roman civilizations but the first documented report was published in the eighteenth century. The hepatovirus belongs to the Picornaviridae family, and carries a single strand RNA. There are 7 genotypes. Antibodies of the IgM and IgA classes, during natural infections, appear early in the serum, together with the first clinical manifestations of the disease, but they may also appear at the end of the first week of infection. There is a spectrum of clinical presentation: asymptomatic infection, symptomatic without jaundice and symptomatic jaundiced. A rare fatal form of hepatitis has been described. Diagnosis of the hepatitis A infection is confirmed by the finding of IgM anti-HAV antibodies, routinely performed using an ELISA test. Treatment is supportive. Intramuscular anti-A gamma globulin is used for passive immune prophylaxis, and there is an efficient vaccine for active immune prophylaxis.

The biological meaning of anti-HBC positive result in blood donors: relation to HBV-DNA and to other serological markers

In order to assess the potential risk of anti-HBc-positive blood donors for post-transfusional hepatitis and to investigate whether other HBV serological markers are capable of identifying the presence of the virus, 1000 first-time blood donors were enrolled between June and July 1997. These donors were screened using routine Brazilian blood center tests (HIV 1 and 2, HTLV 1 and 2, Chagas disease, Syphilis, HCV, HBsAg, anti-HBc and ALT ). The 120 (12%) found to be anti-HBc-positive underwent further tests: HBe, anti-HBe, anti-HBs and HBV-DNA by PCR. Ten cases were HBsAg positive and all were HBV-DNA positive by PCR. Three HBsAg-negative donors were HBV-DNA-positive. Two HBV-DNA-positive donors were also anti-HBs-positive. All the HBV-positive donors had at least one HBV marker other than anti-HBc. Anti-HBc is an important cause of blood rejection. Testing for HBsAg alone is not fully protective and anti-HBc remains necessary as a screening test. The presence of anti-HBs is not always indicative of absence of the virus. The addition of other HBV serological markers could represent an alternative in predicting the presence of the virus when compared with PCR. It is recommended that other studies should be carried out to confirm this finding.

[Prevalence of hepatitis A and E virus infection in school children of an Amazonian municipality in Mato Grosso State]

The prevalence of antibodies to hepatitis A anti-HAV total and E viruses anti-HEV IgG was assessed in 487 children ranging from 2 to 9 years old who were students of nurseries and public schools in a county of the Amazonian region, in Mato Grosso State, Brazil. The anti-HAV and anti-HEV prevalence were 86.4% (CI 95% 83 - 89.3) and 4.5% (CI95% 2.9 - 6.9), respectively. The anti-HAV prevalence was high in all ages, suggesting that this is an area of high endemicity for HAV infection. There was no association between the anti-HAV markers and gender, socioeconomic level, parental educational level, hygienic conditions, number or density of residents per room or schools in which they studied. Anti-HEV prevalence was low and similar to that found among adults in another Brazilian regions.

A two-dose combined vaccine against hepatitis A and hepatitis B in healthy children and adolescents compared to the corresponding monovalent vaccines

BACKGROUND

Immunization against hepatitis A and B has been available for some time, protecting against both infections. With a view to achieving further reduction in the number of interventions and increasing convenience of the vaccinee, we investigated the reactogenicity and immunogenicity of a combined hepatitis A and B vaccine in healthy 4- to 20-year-old subjects at a 0, 6-month schedule.

METHODS

Two hundred forty-eight study subjects were allocated to two study groups and received either two doses of the combined hepatitis A and B vaccine (68% of subjects) or the corresponding monovalent hepatitis A and hepatitis B vaccines (32% of subjects) concomitantly in opposite arms. Reactogenicity was assessed via diary cards after each vaccination. Serum samples were analyzed at months 1, 2, 6, and 7.

RESULTS

All vaccines were well tolerated and very few symptoms were scored as severe. All but one subject seroconverted for anti-hepatitis A virus (anti-HAV) antibodies (98.6%) and 100% of subjects seroconverted for anti-hepatitis B (HBs) antibodies, with respective seroprotection rates of 98.7% for the combined vaccine group and 95.9% for the concomitant vaccine group (p >0.05), respectively. Geometric mean titers were higher in the group receiving the combined vaccine: 6,635 mIU/mL vs. 2,728 mIU/mL (p = 0.0001) for anti-HAV and 3,362 mIU/mL vs. 1,724 mIU/mL (p = 0.0205) for anti-HBs, respectively. Younger subjects had a stronger immune response compared to older subjects.

CONCLUSIONS

The combined hepatitis A and B vaccine was well tolerated at this two-dose schedule. The combined vaccine had higher immunogenicity, probably explained by a adjuvant effect of the antigens. Vaccination programs requiring fewer injections will most likely have a positive impact on compliance rate and comfort of the vaccinee.