Prevalence and epidemiological characteristics of human immunodeficiency virus-1 infection in an iron mining area with intense migratory flow in Pará State, Brazilian amazon, 2005-2014.

Acquired immunodeficiency syndrome (AIDS) caused by human immunodeficiency virus (HIV) is a major global public health problem. The aim of this study is to determine the prevalence of HIV-1 infection in four municipalities of Pará State (Marabá, Parauapebas, Curionópolis, and Canaã dos Carajás), in northern, Brazil. The municipalities are located in the Carajás Complex iron mining area. The employment opportunities result in extensive migratory flow of people. A total of 4771 serum samples were obtained from 2005 to 2014 and were sent to Evandro Chagas Institute, Belém-Pará, where they were tested by enzyme-linked immunosorbent assay, with reactive samples confirmed by Western blot analysis. The samples were from individuals from 23 Brazilian states and the Federal District, mainly Maranhão (39.53%) and other municipalities of Pará (34.25%). The total positivity rate was 0.48% (23/4771). The rate was 0.47% (14/2975) in males and 0.50% (9/1796) in females. Of these, 0.33% (14/4275) were from asymptomatic individuals whose serum were collected during the serological survey, 1.81% (9/497) were from cases featuring clinical symptoms including fever/diarrhea/jaundice, which were included in febrile, diarrheal, and icteric syndromes analyzed during the study. The findings indicated the presence of HIV-1 infection in the general population studied. The majority of cases (60.9%, 14 of 23 positive cases) were asymptomatic.

Identification of two sublineages of genotype G2 rotavirus among diarrheic children in Parauapebas, Southern Pará State, Brazil.

On a world scale, group A human rotaviruses are the most common cause of severe acute gastroenteritis during infancy and childhood, including five (G1, G2, G3, G4, and G9) epidemiologically important genotypes. Among these, G2 denotes a different genogroup which appears to have a cyclic pattern of occurrence and yet little information is available about its genetic variability. The aim of this report was to characterize the emergence of G2 genotype in Paraupebas, Southern Pará State, Brazil, some of which detected after introduction of rotavirus vaccine. A total of 241 fecal specimens from young children with acute gastroenteritis were collected from the "Yutaka Takeda Hospital," a Municipality Hospital, and at the Parauapebas' Health Unit, Pará, from January to September 2006 and during March to November 2008. All samples were tested for rotavirus using immunochromatography, polyacrylamide gel electrophoresis (PAGE), and RT-PCR, yielding an overall positivity of 12.45% (30/241). Rotavirus G2P[4] was identified in 27 of 30 samples (90%), followed by G1P[8] (2/30, 6.67%) and G9P[8] (1/30, 3.33%). Phylogenetic analysis was performed in 15 of the G2 strains, all of which grouped into lineage II. Four of these strains clustered into sublineage II-a (year 2006) and 11 into one possible new sublineage named II-c (year 2008, except SAL-1920-C). The recent re-emergence of G2 genotype associated with lineage II in Brazil warrants the continuous monitoring of circulating rotavirus strains following the nationwide universal use of rotavirus vaccine.

Hepatitis D and B virus genotypes in chronically infected patients from the Eastern Amazon Basin.

Hepatitis D virus (HDV) is a defective hepatotropic virus whose infectivity is dependent on hepatitis B virus (HBV). HDV super- or co-infection leads to an increased risk of fulminant hepatitis or progression to severe chronic liver disease in HBV infected patients. The Brazilian Amazon Basin has been reported to be endemic for HBV and HDV, especially in the Western Amazon Basin. In this region, HDV infection is frequently associated with acute fulminant hepatitis with characteristic histologic features. HDV is classified into seven major clades (HDV-1 to HDV-7) and HBV is subdivided into eight genotypes (A-H). HDV and HBV genotypes have been shown to have a distinct geographic distribution. The aim of this study was to determine the HBV and HDV genotypes harbored by chronically infected patients from the Eastern Amazon Basin, Brazil. We studied 17 serum samples from HBV and HDV chronically infected patients admitted to a large public hospital (Santa Casa de Misericórdia) at Belém, state of Pará, Brazil, between 1994 and 2002. HDV-3 and HBV genotype A (subtype adw2) have been identified in all cases, in contrast to previous studies from other regions of the Amazon, where HBV genotype F has been found co-infecting patients that harbored HDV-3. The HDV-3/HBV-A co-infection suggests that there is not a specific interaction between HBV and HDV genotypes, and co-infection might merely reflect the most frequent genotypes found in a particular geographic area. The analysis of the carboxy-terminal region of the large hepatitis D antigen (L-HDAg), which interacts with the hepatitis B surface antigen (HBsAg) and is essential for HDV assembly, showed some diversity between the different isolates from the Eastern Amazon. This diversity is not observed among HDV-3 sequences from other South American regions.

Reemergence of Oropouche fever, northern Brazil.

Oropouche fever has reemerged in Parauapebas and Porto de Moz municipalities, Pará State, Brazil. Serologic analysis (immunoglobulin M-ELISA) and virus isolation confirmed Oropouche virus (OROV) in both municipalities. Nucleotide sequencing of 2 OROV isolates from each location indicated genotypes I (Parauapebas) and II (Porto de Moz) in Brazil.

Bat-transmitted human rabies outbreaks, Brazilian Amazon.

We describe 2 bat-transmitted outbreaks in remote, rural areas of Portel and Viseu Municipalities, Pará State, northern Brazil. Central nervous system specimens were taken after patients' deaths and underwent immunofluorescent assay and histopathologic examination for rabies antigens; also, specimens were injected intracerebrally into suckling mice in an attempt to isolate the virus. Strains obtained were antigenically and genetically characterized. Twenty-one persons died due to paralytic rabies in the 2 municipalities. Ten rabies virus strains were isolated from human specimens; 2 other cases were diagnosed by histopathologic examination. Isolates were antigenically characterized as Desmodus rotundus variant 3 (AgV3). DNA sequencing of 6 strains showed that they were genetically close to D. rotundus-related strains isolated in Brazil. The genetic results were similar to those obtained by using monoclonal antibodies and support the conclusion that the isolates studied belong to the same rabies cycle, the virus variants found in the vampire bat D. rotundus.

Bat-transmitted Human Rabies Outbreaks, Brazilian Amazon

We describe 2 bat-transmitted outbreaks in remote, rural areas of Portel and Viseu Municipalities, Pará State, northern Brazil. Central nervous system specimens were taken after patients' deaths and underwent immunofluorescent assay and histopathologic examination for rabies antigens; also, specimens were injected intracerebrally into suckling mice in an attempt to isolate the virus. Strains obtained were antigenically and genetically characterized. Twenty-one persons died due to paralytic rabies in the 2 municipalities. Ten rabies virus strains were isolated from human specimens; 2 other cases were diagnosed by histopathologic examination. Isolates were antigenically characterized as Desmodus rotundus variant 3 (AgV3). DNA sequencing of 6 strains showed that they were genetically close to D. rotundus–related strains isolated in Brazil. The genetic results were similar to those obtained by using monoclonal antibodies and support the conclusion that the isolates studied belong to the same rabies cycle, the virus variants found in the vampire bat D. rotundus.

[The evolution of knowledge about viral hepatitis in Amazon region: from epidemiology and etiology to the prophilaxy]. / A evolução do conhecimento sobre as hepatites virais na região amazônica: da epidemiologia e etiologia à prevenção.

Since the 1950 years a disease similar to yellow fever but thought to be a new disease with unknown etiology has been described to health and researcher authorities. This disease occurs in Jurua, Purus and Madeira Rivers valleys. It is feared by local people by its high lethality. It is clinically a hepato-encephalopathy (Average survival time of 5-6 days) About 90% of sick people with typical symptoms go to death. The disease is popularly known as black fever of Lábrea and by pathologist as Lábrea hepatites after the city where the first cases were observed. The specific histopatologic picture of vesicular degeneration of hepatocytes like spider cells motivate the local pathologist to think as a new disease: Lábrea hepatitis. The finding of HBsAg and marker of hepatites D virus (HDV) in the serum motivate the researchers to think the disease as a superinfection of HDV in chronic carriers of HBV. In absence of a specific vaccine against HDV, the vaccine against HBV, must be given soon after the birth is the recommended prevention.

[Hepatitis B and C virus infection and the hepatocellular carcinoma in the East Amazon, Brazil]. / Infecções pelos vírus das hepatites B e C e o carcinoma hepatocelular na Amazônia oriental.

In order to contribute to a better understanding of the possible role of hepatits B and C in the etiopathogenis of HCC in the East Amazon, there were studied 36 patients in Belém/PA. Serological hepatitis markers were evaluated and polymerase chain reaction assays were used to detect HBV-DNA and HCV-RNA. Alcohol abuse was observed in 33.3% and cirrhosis in 83.3%. In 88.9% of the sample, one or more hepatitis B markers were positive. Also, 8.3% those patients had anti-HCV simultaneously positive. The HBsAg serological test was positive in 58.3%; anti-HBc in 86%; anti-HBe in 85.7%; anti-HBe in 9.5%; IgM anti-HBc in 57.1%. The HBV DNA was found in 37.7% and in 65% of the HBsAg positive. The HCV RNA was detected in 8.5% and in 100% of the patients positive to anti-HCV. The AFP was above the normal value in 88.9% of patients, with levels up to 400ng/ml in 75% of them. In conclusion, hepatitis B virus infection seems to be important in the etiology of HCC and improving measures such immunization and screening in the risk population should be emphasyzed.

Multicenter study on the immunogenicity and safety of two recombinant vaccines against hepatitis B

The immunogenicity and safety of a new recombinant hepatitis B vaccine from the Instituto Butantan (Butang®) were evaluated in a multicenter, double-blind, prospective equivalence study in three centers in Brazil. Engerix B® was the standard vaccine. A total of 3937 subjects were recruited and 2754 (70 percent) met all protocol criteria at the end of the study. All the subjects were considered healthy and denied having received hepatitis B vaccine before the study. Study subjects who adhered to the protocol were newborn infants (566), children 1 to 10 years old (484), adolescents from 11 to 19 years (740), adults from 20 to 30 years (568), and adults from 31 to 40 years (396). Vaccine was administered in three doses on the schedule 0, 1, and 6 months (newborn infants, adolescents, and adults) or 0, 1, and 7 months (children). Vaccine dose was intramuscular 10 æg (infants, children, and adolescents) or 20 æg (adults). Percent seroprotection (assumed when anti-HBs titers were > 10mIU/ml) and geometric mean titer (mIU/ml) were: newborn infants, 93.7 percent and 351.1 (Butang®) and 97.5 percent and 1530.6 (Engerix B®); children, 100 percent and 3600.0 (Butang®) and 97.7 percent and 2753.1 (Engerix B®); adolescents, 95.1 percent and 746.3 (Butang®) and 96 percent and 1284.3 (Engerix B®); adults 20-30 years old, 91.8 percent and 453.5 (Butang®) and 95.5 percent and 1369.0 (Engerix B®); and adults 31-40 years old, 79.8 percent and 122.7 (Butang®) and 92.4 percent and 686.2 (Engerix B®). There were no severe adverse events following either vaccine. The study concluded that Butang® was equivalent to Engerix B® in children, and less immunogenic but acceptable for use in newborn infants, adolescents, and young adults.

Multicenter study on the immunogenicity and safety of two recombinant vaccines against hepatitis B.

The immunogenicity and safety of a new recombinant hepatitis B vaccine from the Instituto Butantan (Butang) were evaluated in a multicenter, double-blind, prospective equivalence study in three centers in Brazil. Engerix B was the standard vaccine. A total of 3937 subjects were recruited and 2754 (70%) met all protocol criteria at the end of the study. All the subjects were considered healthy and denied having received hepatitis B vaccine before the study. Study subjects who adhered to the protocol were newborn infants (566), children 1 to 10 years old (484), adolescents from 11 to 19 years (740), adults from 20 to 30 years (568), and adults from 31 to 40 years (396). Vaccine was administered in three doses on the schedule 0, 1, and 6 months (newborn infants, adolescents, and adults) or 0, 1, and 7 months (children). Vaccine dose was intramuscular 10 microg (infants, children, and adolescents) or 20 microg (adults). Percent seroprotection (assumed when anti-HBs titers were > 10 mIU/ml) and geometric mean titer (mIU/ml) were: newborn infants, 93.7% and 351.1 (Butang) and 97.5% and 1530.6 (Engerix B); children, 100% and 3600.0 (Butang) and 97.7% and 2753.1 (Engerix B); adolescents, 95.1% and 746.3 (Butang) and 96% and 1284.3 (Engerix B); adults 20-30 years old, 91.8% and 453.5 (Butang) and 95.5% and 1369.0 (Engerix B); and adults 31-40 years old, 79.8% and 122.7 (Butang) and 92.4% and 686.2 (Engerix B). There were no severe adverse events following either vaccine. The study concluded that Butang was equivalent to Engerix B in children, and less immunogenic but acceptable for use in newborn infants, adolescents, and young adults.

A evolução do conhecimento sobre as hepatites virais na região amazônica: da epidemiologia e etiologia à prevenção / The evolution of knowledge about viral hepatitis in Amazon region: from epidemiology and etiology to the prophilaxy

Desde os anos cinqüenta uma doença similar a febre amarela, porém considerada como nova doença, ocorre em áreas dos vales dos Rios Juruá, Purus e Madeira. Temida pelos residentes locais pela alta letalidade, sendo clinicamente uma hepato-encefalopatia de evolução fulminante (média de 5 a 6 dias). Dos que apresentam manifestações neurológicas 90% evoluem a óbito. A doença é popularmente conhecida como febre negra de Lábrea e pelos patologistas como hepatite de Lábrea pela histopatologia hepática mostrar o aspecto vacuolar dos hepatócitos, daí considerarem-na uma nova doença. Incide principalmente em crianças e adolescentes do sexo masculino. O achado do HBsAg e de marcadores de vírus da hepatite D no soro e fígado dos pacientes, levaram os pesquisadores a considerarem a febre negra de Lábrea como uma superinfecção ou coinfecção do HDV. Na falta de vacina específica contra o HDV, a vacinação contra hepatite B aplicada após o nascimento é a prevenção recomendada.

Since the 1950 years a disease similar to yellow fever but thought to be a new disease with unknown etiology has been described to health and researcher authorities. This disease occurs in Jurua, Purus and Madeira Rivers valleys. It´is feared by local people by its high lethality. It´is clinically a hepato-encephalopathy (Average survival time of 5-6 days) About 90% of sick people with typical symptoms go to death. The disease is popularly known as black fever of Lábrea and by pathologist as Lábrea hepatites after the city where the first cases were observed. The specifc histopatologic picture of vesicular degeneration of hepatocytes like spider cells motivate the local pathologist to think as a new disease: Lábrea hepatitis. The finding of HBsAg and marker of hepatites D vírus (HDV) in the serum motivate the researchers to think the disease as a superinfection of HDV in chronic carriers of HBV. In absence of a specific vaccine against HDV, the vaccine against HBV, must be given soon after the birth is the recommended prevention.

Infecções pelos vírus das hepatites B e C e o carcinoma hepatocelular na Amazônia oriental / Hepatitis B and C virus infection and the hepatocellular carcinoma in the east Amazon, Brazil

Com o objetivo de contribuir para um melhor conhecimento do envolvimento das infecções pelos vírus das hepatites B e C, na etioepidemiologia do CHC na Amazônia Oriental, estudou-se 36 pacientes em Belém-PA. Foram avaliados marcadores sorológicos e a pesquisa do HBV-DNA e HCV-RNA pela reação em cadeia da polimerase. Observou-se etilismo em 33,3% e cirrose em 83,3%. Marcadores sorológicos das infecções pelo HBV e HCV foram encontrados respectivamente em 88,9% e 8,3%. O HBsAg foi encontrado em 58,3%; anti-HBc em 86%; anti-HBe em 85,7; HBeAg em 9,5%; anti-HBc IgM em 57,1%. O HBV-DNA foi detectado em 37,7% e em 65% dos HBsAg positivos; o HCV-RNA em 8,5% e em 100% dos anti-HCV positivos. AFP esteve alterada em 88,9% e acima de 400ng/ml em 75% dos casos. Conclui-se que a infecção pelo HBV parece ter importância na etiologia do CHC e ressalta-se a importância de implementar programas de vacinação e detecção precoce do tumor.

In order to contribute to a better understanding of the possible role of hepatits B and C in the etiopathogenis of HCC in the East Amazon, there were studied 36 patients in Belém/PA. Serological hepatitis markers were evaluated and polymerase chain reaction assays were used to detect HBV-DNA and HCV-RNA. Alcohol abuse was observed in 33.3% and cirrhosis in 83.3%. In 88.9% of the sample, one or more hepatitis B markers were positive. Also, 8.3% those patients had anti-HCV simultaneously positive. The HBsAg serological test was positive in 58.3%; anti-HBc in 86%; anti-HBe in 85.7%; anti-HBe in 9.5%; IgM anti-HBc in 57.1%. The HBV DNA was found in 37.7% and in 65% of the HBsAg positive. The HCV RNA was detected in 8.5% and in 100% of' the patients positive to anti-HCV. The AFP was above the normal value in 88.9% of patients, with levels up to 400ng/ml in 75% of them. In conclusion, hepatitis B virus infection seems to be important in the etiology of HCC and improving measures such immunization and screening in the risk population should be emphasyzed.

Estudo multicêntrico de imunogenicidade e reatogenicidade de vacinas contra hepatite B: informe preliminar / Multicenter study on immunogenicity and reactogenicity of vaccines against hepatitis B: a preliminary report

O Instituto Butantan desenvolveu uma vacina recombinante contra a hepatitie B (Butang). Visando subsidiar o Programa Nacional de Imunizações (PNI)do Ministério da Saúde quanto à incorporação do produto na rotina de vacinação, foi realizado um ensaio clínico com o objetivo de determinar a imunogenicidade e segurança da vacina Butang em indivíduos menores de 41 anos de idade

Hepatitis B virus surface antigen (HBsAg) and antibody (anti-HBs) forming immune complexes in fulminant hepatits

Este trabalho relata um padräo sorológico näo usual para o HBV e a presença de imunocomplexos HBsAg/anti-HBs em amostras de soro provenientes de dois pacientes com hepatite fulminante procedentes da Amazônia Ocidental Brasileira. O diagnóstico foi estabelecido por meio de testes sorológicos e pela demonstraçäo de complexos antígeno/anticorpo por técnicas de microscopia eletrônica de transmissäo. A concomitante superinfecçäo pelo vírus da hepatite Delta também é discutida

Transfusion-transmited virus (TTV) in Brazil: preliminary report

TTV e um virus DNA recentemente descoberto no Japao a partir de um paciente portador de hepatite pos-transfusional de origem desconhecida. Neste estudo, avaliamos a presenca deste virus em pacientes com hepatopatias cronicas dos estados de Sao Paulo e do Para, representando duas regioes geograficamente diferentes. O DNA do TTV foi encontrado em 21/105 (20 por cento) e 9/20 (45 por cento) dos casos de Sao Paulo e do Para, respectivamente. O sequenciamento do DNA amplificado confirmou a presenca dos genotipos 1a e 2a, bem como de outros genotipos ainda nao descritos ate o momento. Em conclusao, TTV esta presente em casos de hepatopatias cronicas do Sudeste e do Norte do Brasil. por outro lado, maiores estudos ainda sao necessarios antes de se estabelecer relacao causal entre o TTV e a hepatite em seres humanos

Hepatite pelo vírus C (HCV) em crianças e adolescentes hemofílicos / Hepatitis C virus (HCV) in children and adolescent hemophiliacs

Objetivo: Avaliar a soroprevalência de infecçäo pelo HCV entre hemofílicos no Estado do Pará e a possível relaçäo com nível sérico de enzimas hepáticas, tipo de hemofilia, idade, gravidade, combinaçäo e tipo de tratamento e data de início de tratamento como hemoderivados. Métodos: Estudo epidemiológico com corte transversal, analisando 62 pacientes hemofílicos do Centro de Hemoterapia do Pará (HEMOPA), nascidos a partir de 01/01/80, através de revisäo de prontuário, exame físico e exames laboratoriais: Anti-HCV (ELISA 3ª geraçäo). Reaçäo de cadeia de polimerase - PCR - (HCV-RNA) e dosagem de nível séricos de trasaminases (ALT e AST). A análise estatística dos dados foi feita aplicando os testes do qui-quadrado e o teste exato de Fisher, considerando-se significantes os resultados de p<_ 0,05. Resultados: Dos 62 pacientes analisados, 48,4 por cento (n=30) eram soropositivos para o HCV. Dentre estes pacientes, 43,3 por cento (n=13) apresentavam viremia com detecçäo de RNA viral pela técnica de PCR. A infecçäo pelo HCV se relacionou com data de início de tratamento anterior a 1993 (p= 0,0005); com o tipo hemofilia, sendo o tipo A mais freqüente (p= 0,028); com gravidade, sendo mais freqüente na forma moderada (p= 0,026); e com faixa etária, sendo mais freqüente acima dos 5 anos de idade (p= 0,025). Conclusöes: A infecçäo pelo HCV entre hemofílico no Estado do Pará é elevada (48,4 por cento) e se relacionou com início do tratamento anterior a 1993...

Epidemiología dos vírus das hepatites B, C e D na tribo indígena parakana, amazonia oriental brasileira / Epidemiology of hepatitis B, C and D viruses among the parakana tribe in the eastern brazilian amazon region

Este estudo visa a establecer a prevalencia das infecçoes pelos vírus das hepatites B, C e D (HBV, HCV e HDV) e discutir a transmissao dos mesmos na tribo indígena parakaná, do Estado do Pará, Brasil. Os primeiros contatos desta tribo com membros da sociedade brasileira ocorreram nas décadas de 1970 e 1980. Em outubro de 1992, a tribo era composta por 350 indivíduos 222 vivendo na aldeia Paranatinga e 128 na aldeia Maroxewara. Examinaram-se amostras de soro de 96,9 por cento dessa populaçao pelos métodos inmunoenzimáticos para mercadores das infecçoes pelos vírus acima citados. Examinaram-se também 106 amostras de soro, coletadas dos parakanas na década de 70. Os resultados do estudo atual demonstram prevalencia total de 84,7 por cento de infecçao pelo HBV na aldeia Paranatinga, onde havia 14,4 por cento portadores. Na aldeia Maroxewara registrou-se apenas 17,7 por cento de prevalencia total da infecçao, nao sendo detectados portadores do vírus entre os examinados. A pesquisa de marcadores de infecçao pelo HDV foi negativa entre os portadores do HBV. A prevalencia de infecçao pelo HCV, confirmadas por imunoblot, foi de 1,4 e 1,6 por cento nas aldeias de Paranatinga e Maroxewara, respectivamente. Dentre as informaçoes fornecidas pelo presente estudo destacam-se: a caracterizaçao da transmissao horizontal do HBV em idade precoce na aldeia Paranatinga, a diferença de prevalencia de infectados pelo HBV entre as duas aldeias de uma mesma tribo (geograficamente próximas), a detecçao de infecçap pelo HCV nas duas aldeias, a baixa prevalencia de infecçao pelo HBV e a ausencia de infecça pelo HCV nos primeiros anos de contato da tribo parakaná

Epidemiología dos vírus das hepatites B, C e D na tribo indígena parakana, amazonia oriental brasileira / Epidemiology of hepatitis B, C and D viruses among the parakana tribe in the eastern brazilian amazon region

Este estudo visa a establecer a prevalencia das infecçoes pelos vírus das hepatites B, C e D (HBV, HCV e HDV) e discutir a transmissao dos mesmos na tribo indígena parakaná, do Estado do Pará, Brasil. Os primeiros contatos desta tribo com membros da sociedade brasileira ocorreram nas décadas de 1970 e 1980. Em outubro de 1992, a tribo era composta por 350 indivíduos 222 vivendo na aldeia Paranatinga e 128 na aldeia Maroxewara. Examinaram-se amostras de soro de 96,9 por cento dessa populaçao pelos métodos inmunoenzimáticos para mercadores das infecçoes pelos vírus acima citados. Examinaram-se também 106 amostras de soro, coletadas dos parakanas na década de 70. Os resultados do estudo atual demonstram prevalencia total de 84,7 por cento de infecçao pelo HBV na aldeia Paranatinga, onde havia 14,4 por cento portadores. Na aldeia Maroxewara registrou-se apenas 17,7 por cento de prevalencia total da infecçao, nao sendo detectados portadores do vírus entre os examinados. A pesquisa de marcadores de infecçao pelo HDV foi negativa entre os portadores do HBV. A prevalencia de infecçao pelo HCV, confirmadas por imunoblot, foi de 1,4 e 1,6 por cento nas aldeias de Paranatinga e Maroxewara, respectivamente. Dentre as informaçoes fornecidas pelo presente estudo destacam-se: a caracterizaçao da transmissao horizontal do HBV em idade precoce na aldeia Paranatinga, a diferença de prevalencia de infectados pelo HBV entre as duas aldeias de uma mesma tribo (geograficamente próximas), a detecçao de infecçap pelo HCV nas duas aldeias, a baixa prevalencia de infecçao pelo HBV e a ausencia de infecça pelo HCV nos primeiros anos de contato da tribo parakaná