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.

Serological evidence of hantavirus infection in rural and urban regions in the state of Amazonas, Brazil.

Hantavirus disease is caused by the hantavirus, which is an RNA virus belonging to the family Bunyaviridae. Hantavirus disease is an anthropozoonotic infection transmitted through the inhalation of aerosols from the excreta of hantavirus-infected rodents. In the county of Itacoatiara in the state of Amazonas (AM), Brazil, the first human cases of hantavirus pulmonary and cardiovascular syndrome were described in July 2004. These first cases were followed by two fatal cases, one in the municipality of Maués in 2005 and another in Itacoatiara in 2007. In this study, we investigated the antibody levels to hantavirus in a population of 1,731 individuals from four different counties of AM. Sera were tested by IgG/IgM- enzyme-linked immune-sorbent assay using a recombinant nucleocapsid protein of the Araraquara hantavirus as an antigen. Ten sera were IgG positive to hantavirus (0.6%). Among the positive sera, 0.8% (1/122), 0.4% (1/256), 0.2% (1/556) and 0.9% (7/797) were from Atalaia do Norte, Careiro Castanho, Itacoatiara and Lábrea, respectively. None of the sera in this survey were IgM-positive. Because these counties are distributed in different areas of AM, we can assume that infected individuals are found throughout the entire state, which suggests that hantavirus disease could be a local emerging health problem.

Low prevalence of hepatitis B virus, hepatitis D virus and hepatitis C virus among patients with human immunodeficiency virus or acquired immunodeficiency syndrome in the Brazilian Amazon basin.

Comorbidities in human immunodeficiency virus infection are of great interest due to their association with unfavorable outcomes and failure of antiretroviral therapy. This study evaluated the prevalence of coinfection by human immunodeficiency virus and viral hepatitis in an endemic area for hepatitis B in the Western Amazon basin. Serological markers for hepatitis B virus, hepatitis C virus and hepatitis D virus were tested in a consecutive sample of all patients referred for treatment of human immunodeficiency virus or acquired immunodeficiency syndrome. The variables sex, age, origin and exposure category were obtained from medical records and from the sexually transmitted diseases and acquired immunodeficiency syndrome surveillance database. Among 704 subjects, the prevalence of chronic hepatitis B carriage was 6.4% and past infection 40.2%. The presence of hepatitis B was associated with birth in hyperendemic areas of the Amazon basin, male sex and illegal drug use. The overall prevalence of hepatitis C was 5% and was associated with illegal drug use. The prevalence of hepatitis B and C among human immunodeficiency virus or acquired immunodeficiency syndrome patients in the Western Amazon basin was lower than seen elsewhere and is probably associated with the local epidemiology of these viruses and the degree of overlap of their shared risk factors. An opportunity presents itself to evaluate the prevention of hepatitis C through harm reduction policies and hepatitis B through vaccination programs among human immunodeficiency virus or acquired immunodeficiency syndrome patients.

[Coinfection between hepatitis B virus and malaria: clinical, serologic and immunologic aspects]. / Co-infecção humana pelo plasmódio e o vírus da hepatite B: aspectos clínicos, sorológicos e imunológicos.

The Amazon region is known for a high prevalence of hepatitis B infection, and accounts for more than 90% of malaria cases in Brazil. It has been suggested that the occurrence of coinfections may be important, and may influence the natural history of both diseases. This study evaluated 545 patients with acute malaria, in Coari, Western Brazilian Amazon. 333 (61.1%) presented Plasmodium vivax malaria, 193 (35.4%) Plasmodium falciparum and 19 (3.5%) mixed infections. The HBsAg prevalence was 4.2% and total anti-HBc 49.7%. Patients with HBV serological markers presented no clinical differences than those with malaria only, nor showed any association with classic signs of hepatic disorder. Although showing no statistical significance, HBsAg reactive subjects presented lower parasitic load and higher antibody titers, suggesting the possibility that the immune response in a coinfected individual is differentiated and leads to a variation in the parasite load and antibody production.

[Seroprevalence of hepatitis B and malaria infection in Lábrea, Brazilian western Amazon: estimates of coinfection rates]. / Soroprevalência da infecção pelo vírus da hepatite B e pelo plasmódio em Lábrea, Amazonas: estimativa da ocorrência de prováveis coinfecções.

The Amazon region is known for the high occurrence of hepatitis B virus (HBV) infection, and accounts for more than 98% of malaria cases in Brazil. Despite the controversy, it has been proposed that when associated they may lead to important effects in the natural history of both infections. This study estimates the prevalence of coinfection within general population of an endemic region of HBV and malaria in the Brazilian Amazon. The prevalence of HBsAg was 3.3% (95% CI 2.1%-5.1%,) and total anti-HBc 49.9% (95% CI 45.9%-53.8%). The prevalence of antibodies against Plasmodium vivax and Plasmodium falciparum antigens was 51.4% (311/605) (95% CI 47.3%-55.4%). Related to the simultaneous presence of malaria antibodies and HBV serological markers, in 1.8% (11/605), (95% CI 1.0%-3.3%), the presence of HBsAg was also demonstrated, mean age 26 years (p <0.001). This study points to similarities in the distribution of these diseases, such as the occurrence mainly among young adults. The events may occur in different times. Also shown differences such as the low risk of malaria in the group up to fifteen years, where HBV circulates with moderate intensity. The prevalence of HBV and malaria coinfection is in fact less than the rates of HBsAg carriage, showing a heterogeneous pattern related to the clinical spectrum of HBV infection.

[Hepatitis B and D virus infection within Amerindians ethnic groups in the Brazilian Amazon: epidemiological aspects]. / Infecção pelos vírus das hepatites B e D entre grupos indígenas da Amazônia Brasileira: aspectos epidemiológicos.

Several studies describe very high prevalence rates of infection and disease of hepatitis B and D within Native American population. This is a review of what has been described among Amerindians of Brazilian Amazon. Some groups show low prevalence rates of HBsAg, whereas, others of the same region reveal high endemic pattern, even among individuals less then 10 years of age. HDV is only found in groups of Amazonas province. Transmission may occur by interfamilial dissemination or sexual contact among young adults. Socio-cultural, genetic, and ecological factors are described as determinants of this unique pattern. Nevertheless, the origin of these two viruses is yet to be disclosed. Amerindians population and their genetic memory are a live experiment, which demands a broad investigation, weighting with modern tools, as molecular biology, the influence of historical, genetic, medical and anthropological factors.

[Prevalence of hepatitis B virus markers within household contacts in the State of Amazonas]. / Prevalência de marcadores para o vírus da hepatite B em contatos domiciliares no Estado do Amazonas.

The aim of our investigation was to evaluate, with a prevalence study, the modes of transmission of Hepatitis B virus (HBV), within infected subjects and their household contacts in the State of Amazon, western Brazilian Amazon. We studied 97 index cases and 258 household contacts. Out of the 258 household contacts of HBV, 51.6% had serological markers of a past infection, 12.0% signs of active infection, suggesting that the virus circulates within household members. The high prevalence among siblings (23.6%) demonstrates the importance of personal contact in the transmission of this virus. Another indirect indicator of intra-familial transmission was the high prevalence of HBV markers within contacts of a fulminant hepatitis. The vertical transmission of HBV in our region may or may not occur, but if it does it as a rare event. Our results demonstrate the importance of the presence of HBV, and demand other investigations to clarify the inter-familial transmission of these viruses in our region.

Clinical and virological descriptive study in the 2011 outbreak of dengue in the Amazonas, Brazil.

BACKGROUND: Dengue is a vector-borne disease in the tropical and subtropical region of the world and is transmitted by the mosquito Aedes aegypti. In the state of Amazonas, Brazil during the 2011 outbreak of dengue all the four Dengue virus (DENV) serotypes circulating simultaneously were observed. The aim of the study was to describe the clinical epidemiology of dengue in Manaus, the capital city of the state of the Amazonas, where all the four DENV serotypes were co-circulating simultaneously. METHODOLOGY: Patients with acute febrile illness during the 2011 outbreak of dengue, enrolled at the Fundação de Medicina Tropical Dr. Heitor Viera Dourado (FMT-HVD), a referral centre for tropical and infectious diseases in Manaus, were invited to participate in a clinical and virological descriptive study. Sera from 677 patients were analyzed by RT-nested-PCRs for flaviviruses (DENV 1-4, Saint Louis encephalitis virus-SLEV, Bussuquara virus-BSQV and Ilheus virus-ILHV), alphavirus (Mayaro virus-MAYV) and orthobunyavirus (Oropouche virus-OROV). PRINCIPAL FINDINGS: Only dengue viruses were detected in 260 patients (38.4%). Thirteen patients were co-infected with more than one DENV serotype and six (46.1%) of them had a more severe clinical presentation of the disease. Nucleotide sequencing showed that DENV-1 belonged to genotype V, DENV-2 to the Asian/American genotype, DENV-3 to genotype III and DENV-4 to genotype II. CONCLUSIONS: Co-infection with more than one DENV serotype was observed. This finding should be warning signs to health authorities in situations of the large dispersal of serotypes that are occurring in the world.

Borderline tuberculoid leprosy and type 1 leprosy reaction in a hepatitis C patient during treatment with interferon and ribavirin.

Hepatitis C is an inflammatory disease of the liver caused by a single-stranded RNA virus belonging to the Hepacivirus genus in the Flaviviridae family, called the hepatitis C virus. After initial infection, 70% to 85% of the patients develop chronic hepatitis C with hepatic fibrosis. In addition to specific liver changes, various extrahepatic manifestations have been associated with the hepatitis C virus infection or with medications used to treat the condition. We report the case of a patient with chronic hepatitis C who presented with the signs and symptoms of borderline tuberculoid leprosy and type 1 reaction four months after the start of treatment with a pegylated interferon/ribavirin combination.

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.

Molecular characterization of the hepatitis B virus in autochthonous and endogenous populations in the Western Brazilian Amazon.

INTRODUCTION: Hepatitis B virus (HBV) infection is a serious public health issue worldwide. Hepatitis B virus is classified into eight genotypes, varying from A to H, with distinct geographical distributions. In Brazil, the most frequent genotypes are A, D, and F. METHODS: This study aimed to characterize the HBV genotypes in cases of hepatitis B virus and hepatitis D virus (HDV) co-infections in an endemic area in the Western Brazilian Amazon. We analyzed 86 serum samples reactive for HBsAg from indigenous and non-indigenous populations obtained from previous serological surveys. RESULTS: Of the 86 reactive serum samples, 39 were found to be HBV-DNA-positive by semi-nested PCR. The genotypes were established by sequencing the amplified S gene region. We obtained 20 sequences classified into three genotypes: A, D, and F. Genotype A was the most frequent (60%), followed by D (35%) and F (5%). CONCLUSIONS: The distribution of the HBV genotypes reflected the pattern of historical occupation of the region.

Prevalence of hepatitis B virus infection and carriage after nineteen years of vaccination program in the Western Brazilian Amazon.

INTRODUCTION: Reductions in the prevalence of hepatitis B virus (HBV) infection and carriage, decreases in liver cancer incidence, and changes in patterns of liver dysfunctions are described after hepatitis B vaccination. METHODS: We conducted a population-based seroprevalence study aimed at estimating the HBV prevalence and risk of infection in the rural area of Lábrea following nineteen years of HBV vaccination. RESULTS: Half of the subjects showed total anti-HBc of 52.1% (95% CI 49.6-54.7). The HBsAg prevalence was 6.2% (95% CI 5.1-7.6). Multivariate analysis showed an inverse association between HBV infection and vaccination (OR 0.62; 95% CI 0.44-0.87). HBsAg remained independently associated with past hepatitis (OR 2.44; 95% CI 1.52-3.89) and inversely to vaccination (OR 0.43; 95% CI 0.27-0.69). The prevalence of HBeAg among HBsAg-positive individuals was 20.4% (95% CI 12.8-30.1), with the positive subjects having a median age of 11 years (1-46) p=0.0003. CONCLUSIONS: We demonstrate that HBV infection is still an important public health issue and that HBV vaccination could have had better impact on HBV epidemiology. If we extrapolate these findings to other rural areas in the Brazilian Amazon, we can predict that the sources of chronic infected patients remain a challenge. Future studies are needed regarding clinical aspects, molecular epidemiology, surveillance of acute cases, and risk groups.

Hepatitis D virus infection in the Western Brazilian Amazon - far from a vanishing disease.

INTRODUCTION: A decline in hepatitis D virus (HDV) occurrence was described in Europe and Asia. We estimated HDV prevalence in the Brazilian Amazon following hepatitis B vaccination. METHODS: This is a cross-sectional survey of HDV measured by total antibodies to HDV (anti-HD T). RESULTS: HDV prevalence was 41.9% whiting HBsAg carries and was associated with age (PR = 1.96; 95% CI 1.12-3.42; p = 0.01), hepatitis B virus (HBV) infection (PR = 4.38; 95% CI 3.12-6.13; p < 0.001), and clinical hepatitis (PR =1.44; 95% CI 1.03-2.00; p = 0.03). Risk factors were related to HDV biology, clinical or demographic aspects such as underlying HBV infection, clinical hepatitis and age. CONCLUSIONS: Our study demonstrated that HDV infection continues to be an important health issue in the Brazilian Amazon and that the implementation of the HBV vaccination in rural Lábrea had little or no impact on the spread of HDV. This shows that HDV has not yet disappeared from HBV hyperendemic areas and reminding that it is far from being a vanishing disease in the Amazon basin.

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.

Borderline tuberculoid leprosy and type 1 leprosy reaction in a hepatitis C patient during treatment with interferon and ribavirin / Hanseniase boderline tuberculoide e reacao hansenica do tipo 1 em paciente com hepatite C durante tratamento com interferon e ribavirina

Hepatitis C is an inflammatory disease of the liver caused by a single-stranded RNA virus belonging to the Hepacivirus genus in the Flaviviridae family, called the hepatitis C virus. After initial infection, 70% to 85% of the patients develop chronic hepatitis C with hepatic fibrosis. In addition to specific liver changes, various extrahepatic manifestations have been associated with the hepatitis C virus infection or with medications used to treat the condition. We report the case of a patient with chronic hepatitis C who presented with the signs and symptoms of borderline tuberculoid leprosy and type 1 reaction four months after the start of treatment with a pegylated interferon/ribavirin combination.

A hepatite C é uma doença inflamatória fígado causada por um vírus RNA de fita simples, pertencente ao gênero Hepacivirus e à família Flaviviridae, denominado de vírus da hepatite C. Após infecção inicial 70 a 85% dos pacientes infectados evoluem para hepatite C crônica, com fibrose progressiva. Além das alterações hepáticas específicas, várias manifestações extra-hepáticas têm sido relacionadas à infecção pelo vírus da hepatite C ou às medicações utilizadas no seu tratamento. Nesse trabalho, apresenta-se caso de paciente portador de hepatite C crônica, que manifestou um quadro hanseníase boderline tuberculóide e reação hansênica do tipo I, quatro meses após início do tratamento com interferon peguilado associado à ribavirina.

[Occult hepatitis B: prevalence and clinical characteristics in a population with high endemicity of hepatitis B infection in the western Brazilian Amazon region]. / Hepatite crônica B oculta: prevalência e aspectos clínicos em população de elevada endemicidade de infecção pelo vírus da hepatite B na Amazônia Ocidental Brasileira.

A persistent form of the hepatitis B virus called occult chronic hepatitis B has recently been described. Its prevalence and physiopathology are unknown. The aim of this study was to evaluate the occurrence of this clinical entity among patients in the Brazilian Amazon region. Out of 51 anti-HBc total-positive patients who were tested using the polymerase chain reaction, 17% were positive. We did not find any associations with classical risk factors for hepatitis B virus infection or with biochemical tests, hematological tests or histological patterns. However, the jaundiced and HIV-positive patients showed a statistical association with the presence of hepatitis B virus-DNA. The results demonstrated that occult hepatitis B occurred among our patients, but at prevalence rates lower than expected for this region. We believe that despite the small sample size, the occurrence might have been found to be greater if we had used primers for the S, C and X regions of the hepatitis B virus genome, thereby increasing the sensitivity of the test.

Molecular characterization of the hepatitis B virus in autochthonous and endogenous populations in the Western Brazilian Amazon / Caracterização molecular do vírus da hepatite B em população autóctone e população endógena do município de Lábrea, na Amazônia ocidental brasileira

INTRODUCTION: Hepatitis B virus (HBV) infection is a serious public health issue worldwide. Hepatitis B virus is classified into eight genotypes, varying from A to H, with distinct geographical distributions. In Brazil, the most frequent genotypes are A, D, and F. METHODS: This study aimed to characterize the HBV genotypes in cases of hepatitis B virus and hepatitis D virus (HDV) co-infections in an endemic area in the Western Brazilian Amazon. We analyzed 86 serum samples reactive for HBsAg from indigenous and non-indigenous populations obtained from previous serological surveys. RESULTS: Of the 86 reactive serum samples, 39 were found to be HBV-DNA-positive by semi-nested PCR. The genotypes were established by sequencing the amplified S gene region. We obtained 20 sequences classified into three genotypes: A, D, and F. Genotype A was the most frequent (60 percent), followed by D (35 percent) and F (5 percent). CONCLUSIONS: The distribution of the HBV genotypes reflected the pattern of historical occupation of the region.

INTRODUÇÃO: A infecção pelo vírus da hepatite B (VHB) é um importante problema de saúde pública no mundo. O VHB é classificado em oito genótipos diferentes, A-H, com distinta distribuição geográfica. No Brasil, os genótipos mais frequentes são o A, D e F. MÉTODOS: Objetivo deste estudo foi caracterizar os genótipos do VHB, em região endêmica de infecção pelos vírus da hepatite B e hepatite D (VHD), na Amazônia Ocidental Brasileira. Foram analisadas 86 amostras sororreativas para o HBsAg de indivíduos indígenas e não-indígenas, obtidas de inquéritos sorológicos realizados no município de Lábrea, Estado do Amazonas. RESULTADOS: Das 86 amostras sororreativas, 39 foram VHB-DNA positivas pela semi-nested PCR. Os genótipos foram estabelecidos pelo sequenciamento da região do gene S amplificado. Foram obtidas 20 sequências, classificadas em três genótipos A, D e F; sendo o genótipo A o mais frequente (60 por cento), seguido do D (35 por cento) e F (5 por cento). CONCLUSÕES: O perfil de distribuição dos genótipos encontrados do VHB reflete o padrão de ocupação histórica da região.

Prevalence of hepatitis B virus infection and carriage after nineteen years of vaccination program in the Western Brazilian Amazon / Prevalência da infecção e de portadores do vírus da hepatite B, após 19 anos do programa de vacinação na Amazônia ocidental Brasileira

INTRODUCTION: Reductions in the prevalence of hepatitis B virus (HBV) infection and carriage, decreases in liver cancer incidence, and changes in patterns of liver dysfunctions are described after hepatitis B vaccination. METHODS: We conducted a population-based seroprevalence study aimed at estimating the HBV prevalence and risk of infection in the rural area of Lábrea following nineteen years of HBV vaccination. RESULTS: Half of the subjects showed total anti-HBc of 52.1 percent (95 percent CI 49.6-54.7). The HBsAg prevalence was 6.2 percent (95 percent CI 5.1-7.6). Multivariate analysis showed an inverse association between HBV infection and vaccination (OR 0.62; 95 percent CI 0.44-0.87). HBsAg remained independently associated with past hepatitis (OR 2.44; 95 percent CI 1.52-3.89) and inversely to vaccination (OR 0.43; 95 percent CI 0.27-0.69). The prevalence of HBeAg among HBsAg-positive individuals was 20.4 percent (95 percent CI 12.8-30.1), with the positive subjects having a median age of 11 years (1-46) p=0.0003. CONCLUSIONS: We demonstrate that HBV infection is still an important public health issue and that HBV vaccination could have had better impact on HBV epidemiology. If we extrapolate these findings to other rural areas in the Brazilian Amazon, we can predict that the sources of chronic infected patients remain a challenge. Future studies are needed regarding clinical aspects, molecular epidemiology, surveillance of acute cases, and risk groups.

INTRODUÇÃO: Reduções nas taxas de prevalência de infecção pelo vírus da hepatite B (VHB) e de portadores, incidência de câncer de fígado e mudança nos padrões de doenças hepáticas são descritos, depois da introdução da vacinação contra hepatite B. MÉTODOS: Foi conduzido um estudo de soro prevalência de base populacional, com o objetivo de estimar a prevalência do VHB e fatores de risco de infecção na área rural de Lábrea, depois de 19 anos de introdução da vacinação contra hepatite B. RESULTADOS: Metade dos indivíduos investigados mostrou reatividade ao anti-HBc total, 52,1 por cento (IC 95 por cento 49,6-54,7). A prevalência do HBsAg foi 6,2 por cento (IC 95 por cento 5,1-7,6). Análises multivariadas mostrou associação inversa da infecção pelo VHB e vacinação (OR 0,62; IC 95 por cento 0<44-0,87). A presença do HBsAg permaneceu independentemente associada com o passado de hepatite (OR 2,44; IC 95 por cento 1,52-3,89) e inversamente associado a história de vacinação (OR 0,43; IC 95 por cento 0,27-0,69). A prevalência do HBeAg, entre os HBsAg positivos foi 20,4 por cento (IC95 por cento 12,8-30,1), tendo em média os indivíduos positivos 11 anos de idade (1-46) p=0,0003. CONCLUSÕES: Foi demonstrado que o VHB é ainda um importante problema de saúde publica, e que a vacinação contra o VHB poderia ter tido um impacto maior na epidemiologia do VHB na região. Se esses achados forem extrapolados para outras regiões rurais da Amazônia brasileira, podemos predizer que a fonte de pacientes crônicos é ainda um desafio a ser vencido. Estudos futuros devem focar os aspectos clínicos, a epidemiologia molecular, vigilância de casos agudos e grupos de risco.

Hepatitis D virus infection in the Western Brazilian Amazon - far from a vanishing disease / Infecção pelo vírus da hepatite D na Amazônia brasileira - longe de uma doença em declínio

INTRODUCTION: A decline in hepatitis D virus (HDV) occurrence was described in Europe and Asia. We estimated HDV prevalence in the Brazilian Amazon following hepatitis B vaccination. METHODS: This is a cross-sectional survey of HDV measured by total antibodies to HDV (anti-HD T). RESULTS: HDV prevalence was 41.9% whiting HBsAg carries and was associated with age (PR = 1.96; 95% CI 1.12-3.42; p = 0.01), hepatitis B virus (HBV) infection (PR = 4.38; 95% CI 3.12-6.13; p < 0.001), and clinical hepatitis (PR =1.44; 95% CI 1.03-2.00; p = 0.03). Risk factors were related to HDV biology, clinical or demographic aspects such as underlying HBV infection, clinical hepatitis and age. CONCLUSIONS: Our study demonstrated that HDV infection continues to be an important health issue in the Brazilian Amazon and that the implementation of the HBV vaccination in rural Lábrea had little or no impact on the spread of HDV. This shows that HDV has not yet disappeared from HBV hyperendemic areas and reminding that it is far from being a vanishing disease in the Amazon basin.

INTRODUÇÃO: É descrito declínio na ocorrência do vírus da hepatite D (VHD) na Europa e Ásia. Estimamos a prevalência de infecção pelo VHD na Amazônia Ocidental, após a introdução da vacinação contra hepatite B. MÉTODOS: Este é um estudo de corte transversal da prevalência do VHD medido pela ocorrência de anticorpos totais (anti-HD T). RESULTADOS: A prevalência do VHD encontrada foi 41,9% entre os portadores do HBsAg, e esteve associado à idade (RP = 1,96; IC 95% 1,12-3,42; p = 0,01), infecção pelo HBV (RP = 4,38; IC 95% 3,12-6,13; p < 0,001) e história clínica de hepatite (RP =1,44; IC 95% 1,03-2,00; p = 0,03). Fatores de risco mostraram-se associados à biologia do HDV, aspectos clínicos e demográficos como infecção prévia pelo VHB e idade. CONCLUSÕES: O estudo demonstra que a infecção pelo VHD continua sendo um importante problema de saúde pública na região, e que a implantação da vacinação contra o VHB na área rural de Lábrea teve um impacto pouco significativo no controle do VHD, percebe-se que este ainda não desapareceu de áreas hiperendêmicas do VHB, e está longe de poder ser classificado como uma doença em declínio na bacia Amazônica.

Serological evidence of hantavirus infection in rural and urban regions in the state of Amazonas, Brazil

Hantavirus disease is caused by the hantavirus, which is an RNA virus belonging to the family Bunyaviridae. Hantavirus disease is an anthropozoonotic infection transmitted through the inhalation of aerosols from the excreta of hantavirus-infected rodents. In the county of Itacoatiara in the state of Amazonas (AM), Brazil, the first human cases of hantavirus pulmonary and cardiovascular syndrome were described in July 2004. These first cases were followed by two fatal cases, one in the municipality of Maués in 2005 and another in Itacoatiara in 2007. In this study, we investigated the antibody levels to hantavirus in a population of 1,731 individuals from four different counties of AM. Sera were tested by IgG/IgM- enzyme-linked immune-sorbent assay using a recombinant nucleocapsid protein of the Araraquara hantavirus as an antigen. Ten sera were IgG positive to hantavirus (0.6 percent). Among the positive sera, 0.8 percent (1/122), 0.4 percent (1/256), 0.2 percent (1/556) and 0.9 percent (7/797) were from Atalaia do Norte, Careiro Castanho, Itacoatiara and Lábrea, respectively. None of the sera in this survey were IgM-positive. Because these counties are distributed in different areas of AM, we can assume that infected individuals are found throughout the entire state, which suggests that hantavirus disease could be a local emerging health problem.