| seroprevalence of hepatitis b virus and hepatitis c virus in monte negro in the brazilian western amazon region. | this study was carried out in monte negro (state of rondônia), a village in the brazilian western amazon region, where a university of são paulo medical school program for medical student training in rural assistance took place. it aimed to determine the prevalence of hepatitis b virus and hepatitis c virus, to investigate risk factors for infection, and to evaluate the state immunization program against hepatitis b virus in the region. | 2005 | 15838578 |
| [seroprevalence of hepatitis b and malaria infection in lábrea, brazilian western amazon: estimates of coinfection rates]. | 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 an ... | 2005 | 15895171 |
| [coinfection between hepatitis b virus and malaria: clinical, serologic and immunologic aspects]. | 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% ... | 2006 | 16501762 |
| phylogeny and molecular genetic parameters of different stages of hepatitis b virus infection in patients from the brazilian amazon. | a fragment of 600 bp of the gene which codes for the surface antigen of hepatitis b virus (hbv) was amplified and sequenced from patients who were born in five states of the brazilian amazon (amazonas, pará, acre, rondônia and tocantins). a total of 44 sequences were used for the estimation of molecular genetic parameters and phylogenetic analyses. compared with patients who were asymptomatic, those who had acute hepatitis and chronic liver disease had higher levels of genetic variability and hi ... | 2008 | 18288443 |
| 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 ... | 2008 | 18420172 |
| high prevalence of hepatitis b virus and hepatitis d virus in the western brazilian amazon. | severe cases of hepatitis caused by hepatitis b virus (hbv) or hepatitis d virus (hdv) are often seen in the brazilian amazon, but there is a paucity of epidemiologic studies on viral hepatitis in this area. thus, a cross-sectional study to investigate the prevalence of markers for hbv and hdv was performed. serum samples were collected after participants completed an epidemiologic questionnaire. markers for hbv and hdv were analyzed with an enzyme-linked immunosorbent assay. the hbv genotype wa ... | 2005 | 16222030 |
| [hepatitis b and c virus infection and the hepatocellular carcinoma in the east amazon, brazil]. | 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. ... | 2004 | 15586896 |
| [prevalence of hepatitis b virus genotypes and the occurrence of precore mutation a-1896 and to correlate them with the clinical presentation of chronic hepatitis, in a population group of the eastern amazon region]. | hepatitis b virus (hbv) infection presents itself with a variety of clinical manifestations. the present work aims to describe the prevalence of hbv genotypes and the occurrence of precore mutation a-1896 in a population group of the eastern amazon region of brazil and to correlate them with the clinical presentation of chronic hbv infection. 51 hbsag carriers (hbv-dna positive) were selected and divided into three groups: a (14 asymptomatic subjects), b (20 hbeag positive symptomatic patients) ... | 2004 | 15586894 |
| [hepatitis b and d virus infection within amerindians ethnic groups in the brazilian amazon: epidemiological aspects]. | 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 ... | 2004 | 15586891 |
| epidemiology of viruses causing chronic hepatitis among populations from the amazon basin and related ecosystems. | on the last twenty years, viral hepatitis has emerged as a serious problem in almost all the amerindian communities studied in the amazon basin and in other amazon-related ecological systems from the north and center of south america. studies performed on communities from bolivia, brazil, colombia, peru and venezuela have shown a high endemicity of the hepatitis b virus (hbv) infection all over the region, which is frequently associated to a high prevalence of infection by hepatitis d virus amon ... | 2004 | 14999325 |
| [prevalence of hepatitis b virus markers within household contacts in the state of 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 si ... | 2003 | 14576869 |
| [prevalence of and factors associated with hepatitis b virus markers in a rural population of central brazil]. | to carry out a survey of hepatitis b virus seroepidemiology in a municipality in central brazil, on the border of two large ecosystems, the cerrado (savanna) and the amazon river basin. | 2001 | 11820107 |
| hepatitis c virus prevalence among an immigrant community to the southern amazon, brazil. | a community-based random survey was conducted in a southern brazilian amazonian county aiming to investigate hepatitis c virus (hcv) infection prevalence and the association of demographic variables and lifestyle behaviours. seven hundred eighty individuals were serologically screened with a third generation enzyme-linked immunosorbent assay to detect anti-hcv antibodies between 1994/1995. positive samples were retested for confirmation with a line immunoassay (lia, inno-lia hcv ab iii). most of ... | 1999 | 10585644 |
| a polymerase chain reaction-based assay to identify genotype f of hepatitis b virus. | we have developed a polymerase chain reaction (pcr) assay which distinguishes genotype f from the other genotypes of hepatitis b virus (hbv). the method was used to characterize hbv strains isolated in urban areas of the brazilian amazon. dna was amplified in 54 of a total of 78 hbsag-positive serum samples, using universal, non-genotype-specific primers. only 4 (7.4%) were identified as genotype f by our genotype-specific pcr assay. this proportion is notably lower than that previously reported ... | 1999 | 10347767 |
| outbreak of hepatitis b virus in recent arrivals to the brazilian amazon. | an outbreak of acute hepatitis cases in a small community took place 6 months after the community's arrival to the brazilian amazon. an epidemiological investigation was performed and included residents aged more than two years. study subjects were interviewed and bled to test for hepatitis markers by enzyme immunoassays. around 80% of the village population was surveyed. the overall prevalence of hepatitis b virus (hbv) markers was 75.1% (281/374). the surface antigen of hbv (hbsag) and the igm ... | 1998 | 9700626 |
| hepatitis b epidemiology and cultural practices in amerindian populations of amazonia: the tupí-mondé and the xavánte from brazil. | hepatitis b infection and disease are highly endemic in south america. prevalences of positivity are particularly high in amazonia, and among amerindian peoples in particular. this paper reports the results of a seroepidemiological survey for hepatitis b virus (hbv) carried out among four amerindian populations from the brazilian amazon region: gavião, surui, zoro and navate. rates of positivity to hbv serological markers (hbsag, anti-hbs and or anti-hbc) are very high for the four groups, rangi ... | 1996 | 8783434 |
| epidemiological aspects of hepatitis b and d virus infection in the northern region of amazonas, brazil. | the state of amazonas in the brazilian amazon region is an area of high prevalence of hepatitis b and d virus (hbv and hdv) infection. the aim of this study was to identify epidemiological patterns and risk factors of hbv and hdv infections in barcelos, in the basin of the negro river. a random sample (798 in all) of the total population in the urban area and in 2 rural villages was surveyed. a standardized questionnaire was used and blood samples were tested by enzyme-linked immunosorbent assay ... | 1995 | 8560515 |
| a possible correlation between the host genetic background in the epidemiology of hepatitis b virus in the amazon region of brazil. | the amazon region of brazil is an area of great interest because of the large distribution of hepatitis b virus in specific western areas. seven urban communities and 24 indian groups were visited in a total of 4,244 persons. each individual was interviewed in order to obtain demographic and familial information. whole blood was collected for serology and genetic determinations. eleven genetic markers and three hbv markers were tested. among the most relevant results it was possible to show that ... | 1995 | 8551946 |
| [outbreak of malaria induced among users of injectable drugs]. | five cases of malaria were detected among cocaine users by the local health service in bauru, a city with a population of 260,000, located 324 km from s. paulo, brazil, during the first three weeks of july 1990. autochthonous malaria had not occurred in bauru since 1978, and all the five cases denied having recently traveled to endemic areas. an extensive epidemiologic survey conducted from july 19 to september 13 revealed that the 5 cases were in fact part of a malaria outbreak among endovenous ... | 1993 | 8310273 |
| prevalence of infection with hepatitis delta virus (hdv) among carriers of hepatitis b surface antigen in amazonas state, brazil. | serum samples were non-randomly obtained from apparently healthy inhabitants of 5 villages in the amazonas state, brazil. sera were tested by enzyme immunoassay for the presence of hepatitis b surface antigen (hbsag) and, if this was found, for antibody to hepatitis delta virus (hdv). of 574 people tested, 96 (16.7%) were reactive for hbsag and 33 of these (34.4%) for anti-hdv. the results were analysed according to sex, age and history of jaundice and showed a high prevalence of hepatitis b vir ... | 1988 | 3232188 |
| 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 f ... | 2012 | 22908032 |
| molecular epidemiology of hepatitis b and hepatitis delta viruses circulating in the western amazon region, north brazil. | hepatitis b virus (hbv) and hepatitis d virus (hdv) represent important public health problems in the western amazon region with reported cases of fulminant hepatitis. this cross sectional study describes hbv and hdv genotypes circulating in the brazilian amazon region. | 2014 | 24555665 |
| hiv and sexually transmitted infections at the borderlands: situational analysis of sexual health in the brazilian amazon. | the borderlands are considered areas of increased vulnerability to hiv and sexually transmitted infections (sti). the study aimed to determine the sti/hiv prevalence and risk factors in the triple-border area of the brazilian amazon. | 2012 | 22317841 |
| hepatitis d virus infection in the western brazilian amazon - far from a vanishing disease. | 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. | 2012 | 23295870 |
| hepatitis b infection is associated with asymptomatic malaria in the brazilian amazon. | areas that are endemic for malaria are also highly endemic for hepatitis b virus (hbv) infection. nevertheless, it is unknown whether hbv infection modifies the clinical presentation of malaria. this study aimed to address this question. | 2011 | 21625634 |
| [prevalence of infection for hiv, htlv, hbv and of syphilis and chlamydia in pregnant women in a tertiary health unit in the western brazilian amazon region]. | to estimate the prevalence infection of human immunodeficiency virus (hiv), human t-cell lymphotropic vírus (htlv), hepatitis b virus (hbv), chlamydia trachomatis (c. trachomatis) and syphilis in pregnant women, as well as risk factors associated with these infections, in fundação de medicina tropical do amazonas (fmtam). | 2010 | 20625686 |
| hepatitis b virus and hepatitis delta virus genotypes in outbreaks of fulminant hepatitis (labrea black fever) in the western brazilian amazon region. | the genotypes of hepatitis b (hbv) and delta (hdv) viruses circulating among fulminant hepatitis cases from the western amazon basin of brazil were characterized in this study. hbv and hdv isolates were obtained from liver samples from 14 patients who developed fulminant hepatitis and died during 1978-1989. hbv dna and hdv rna were detected in all samples. phylogenetic analyses of hdv sequences showed that they all clustered with previously characterized sequences of hdv genotype 3 (hdv-3). hbv ... | 2009 | 19605587 |
| [occult hepatitis b: prevalence and clinical characteristics in a population with high endemicity of hepatitis b infection in the western brazilian amazon region]. | 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 bioche ... | 2008 | 19142439 |
| 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 huma ... | 2006 | 17308694 |
| intrafamilial prevalence of hepatitis b virus in western brazilian amazon region: epidemiologic and biomolecular study. | hepatitis b is endemic in the amazon region. | 2006 | 16704537 |
| the hepatitis delta genotype 8 in northeast brazil: the north atlantic slave trade as the potential route for infection. | hepatitis delta virus (hdv) is not well known, even though hdv and hepatitis b virus (hbv) co-infection leads to severe forms of acute and chronic liver diseases. hdv is endemic in the western amazon region. recently, the hdv genotype 8 was found in chronic patients followed at the center for liver studies in the northeast brazil, maranhão. previous studies suggested that this genotype was introduced in maranhão during the slave trade. the presence of hdv in that study, which was done outside th ... | 2016 | 27515509 |
| high prevalence of hbv/a1 subgenotype in native south americans may be explained by recent economic developments in the amazon. | | 2016 | 27267305 |
| characterization of the genotypic profile of hepatitis delta virus: isolation of hdv genotype-1 in the western amazon region of brazil. | the hepatitis delta virus (hdv) is a hepatotropic subvirus that is dependent on the hepatitis b virus (hbv) and supplies the viral envelope containing the surface antigen of hepatitis b. viral genetic diversity is related to the geographical origin of the isolates, and there are at least eight genotypes that are referred to as hdv-1 through hdv-8. hdv-3 is responsible for epidemics of severe and fulminant hepatitis, which are common in northeastern south america. hdv-3 is prevalent in the brazil ... | 2015 | 26112316 |
| hepatitis b in rondônia (western amazon region, brazil): descriptive analysis and spatial distribution. | the amazon is one of the regions who have the highest rates of infection by the hepatitis b virus in the world. objectives this study aimed to evaluate the epidemiological data and spatial distribution of hepatitis b cases reported between 2002 and 2012 in the brazilian state of rondônia. | 2015 | 26017077 |
| full-genome sequences of hepatitis b virus subgenotype d3 isolates from the brazilian amazon region. | the brazilian amazon region is a highly endemic area for hepatitis b virus (hbv). however, little is known regarding the genetic variability of the strains circulating in this geographical region. here, we describe the first full-length genomes of hbv isolated in the brazilian amazon region; these genomes are also the first complete hbv subgenotype d3 genomes reported for brazil. the genomes of the five brazilian isolates were all 3,182 base pairs in length and the isolates were classified as be ... | 2015 | 25742278 |
| occult hepatitis b virus infection among blood donors from the brazilian amazon: implications for transfusion policy. | brazil requires the performance of both a test for hepatitis b surface antigen (hbsag) and a test for antibodies to the core of hepatitis b for blood donor screening. blood centres in regions of high hbv endemicity struggle to maintain adequate stocks in face of the high discard rates due to anti-hbc reactivity. we evaluated the potential infectivity of donations positive for anti-hbc in search of a rational approach for the handling of these collections. | 2014 | 24697276 |
| development of cost-effective real-time pcr test: to detect a wide range of hbv dna concentrations in the western amazon region of brazil. | currently there is a significant risk of infection with hepatitis b virus (hbv) during blood transfusion in high epidemic area. this is due to the pre-seroconversion window period, immunovariant viral strains and the presence of occult hbv infection (obi). the aim of this study was to develop an in-house real-time pcr-based method, which was both ultra-sensitive and efficient offering an alternative method for nucleic acid testing (nat). | 2014 | 24472141 |
| development of a reverse transcription quantitative real-time pcr-based system for rapid detection and quantitation of hepatitis delta virus in the western amazon region of brazil. | the hepatitis delta virus (hdv) is a pathogen that causes a severe and rapidly progressive disease of hepatocytes. the measurement of viral load in the peripheral blood of patients with hdv infections is important for diagnosis, treatment monitoring, and support for follow-up studies of viral replication during the course of the disease. this study reports the development of an assay capable of detecting and quantifying the abundance of hdv particles in serum samples, based on reverse-transcript ... | 2014 | 24316446 |
| evaluation of a histocompatibility antigen related to hepatitis b virus in patients with hepatocellular carcinoma in the western brazilian amazon. | hepatocellular carcinoma is an infection of variable incidence that can be caused by hepatitis b virus (hbv), which is endemic in the amazon region. the diagnosis of hbv can be performed through the use of serum markers such as the hepatitis b surface antigen. the chronic hbv can cause mutagenesis and carcinogenesis, being the susceptibility of infection due to allele human leukocyte antigen (hla). thus, we evaluated the clinical, molecular and laboratory profile (histocompatibility complex) of ... | 2013 | 23661457 |
| molecular epidemiology of hepatitis b virus among the indigenous population of the curuçá and itaquaí rivers, javari valley, state of amazonas, brazil. | 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. | 2012 | 22930043 |
| prevalence of hepatitis b virus infection and carriage after nineteen years of vaccination program in the western brazilian amazon. | 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. | 2012 | 22370822 |
| molecular characterization of the hepatitis b virus in autochthonous and endogenous populations in the western brazilian amazon. | 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. | 2012 | 22370821 |