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1.
Arq. gastroenterol ; 52(3): 200-203, July-Sep. 2015. tab, ilus
Artigo em Inglês | LILACS | ID: lil-762867

RESUMO

BackgroundRural populations present an elevated risk of exposure to hepatitis A virus.ObjectiveThe objective of this study was to estimate the prevalence and risk factors associated with hepatitis A virus infection among residents of rural settlement projects of southwest Goiás, Central Brazil.MethodsA total of 466 residents were interviewed and tested for the detection of anti- hepatitis A virus antibodies by ELISA.ResultsThe global prevalence of anti- hepatitis A virus was 82.2%. In individuals aged 5-9 years and 10-19 years, the prevalence was 15% and 58.8%, respectively. Persons in the 10-19 age group, with a history of life in encampments, with more than five people per residence consuming well water, were predictors for exposure to hepatitis A virus.ConclusionOur results suggest that the hepatitis A virus endemicity in rural settlements in southwest Goiás similar to that found in the urban population of the Midwest Region, confirming the implementation of universal hepatitis A vaccination in children.


ContextoPopulações rurais apresentam um risco elevado de exposição ao vírus da hepatite A.ObjetivoO objetivo deste estudo foi estimar a prevalência e fatores de risco associados à infecção pelo vírus da hepatite A em assentados da região Sudoeste de Goiás, Brasil Central.MétodosUm total de 466 assentados foi entrevistado e testado para detecção de anticorpos anti vírus da hepatite A por ELISA.ResultadosA prevalência global de anti vírus da hepatite A foi de 82,2%. Em indivíduos de 5-9 anos e 10-19 anos, a prevalência foi de 15% e 58,8%, respectivamente. Faixa etária de 10-19 anos, antecedentes de vida em acampamento, mais de cinco pessoas por domicílio e consumir água de poços foram preditores de exposição ao vírus da hepatite.ConclusãoNossos resultados sugerem que a endemicidade do vírus da hepatite em assentamentos rurais do Sudoeste de Goiás é semelhante a encontrada na população urbana da Região Centro-Oeste, ratificando a implementação da vacinação universal contra hepatite A em crianças.


Assuntos
Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Adulto Jovem , Doenças Endêmicas , Hepatite A/epidemiologia , Distribuição por Idade , Brasil/epidemiologia , Vírus da Hepatite A Humana , Hepatite A/virologia , Prevalência , Fatores de Risco , População Rural/estatística & dados numéricos , Inquéritos e Questionários
2.
Rio de Janeiro; s.n; 2013. xvi,108 p. ilus, graf, tab, mapas.
Tese em Português | LILACS | ID: lil-746872

RESUMO

A hepatite A é uma doença hepática aguda, causada pelo vírus da hepatite A (HAV), um vírus de RNA da família Picornaviridae com transmissão fecal-oral. Atualmente, o Brasil apresenta um padrão de endemicidade intermediária da doença. Normalmente, a doença possui curso autolimitado e é benigna, porém existem formas graves que podem causar insuficiência hepática aguda em 0,01 porcento dos casos. Além de medidas sanitárias, outro método importante de prevenção é a utilização de vacinas inativadas, esta porém só é utilizada na imunização de grupos de risco. É conhecido o elevado risco de infecção pelo HAV em comunidades nativas no mundo, no entanto, poucos trabalhos abordam este tema em comunidades indígenas do Brasil. O objetivo deste estudo foi avaliar a prevalência de hepatite A em aldeias e povoados pertencentes a reserva Apinajé, Tocantinópolis/TO. Foram analisadas 799 amostras sorológicas para anti-HAV total, sendo 358 indígenas e 441 dos povoados locais, em onze comunidades geograficamente separadas. Para tal, utilizou-se o Kit imunoenzimático comercial da marca Diasorin®. A prevalência total de anti-HAV na população estudada foi de 85,5 porcento . A localidade que apresentou maior prevalência foi a Aldeia Girassol (95,5 porcento). Observou-se o aumento da prevalência de anti-HAV com o envelhecimento da população, sendo menor a prevalência (32,7 porcento ) observada no grupo etário mais jovem (0-2 anos) e maior prevalência (100 porcento ) acima dos 40 anos de idade. Observa-se que, entre os indígenas, 84,87 porcento possuem anti-HAV reagente e nos povoados 85,97 porcento , não havendo diferença ao comparar estas prevalências.


Observamos que 39 porcento das crianças até 12 anos estão sob risco de adquirir a doença, e até os 5 anos este número sobe para 59 porcento , logo, a população média suscetível à hepatite A é baixa por situar-se entre a faixa de 5 à 14 anos. A reserva Apinajé apresenta prevalência intermediária de anti- HAV, tanto nas aldeias quanto nos povoados. Em relação a tendência de soroconversão de hepatite A, nas aldeias isto ocorre com maior frequência durante a transição da fase pré-escolar para escolar, enquanto que nos povoados este risco se dá entre a fase escolar e a adolescência. A prevalência encontrada em crianças e adolescentes reforça a possibilidade da implementação da vacina contra hepatite A no calendário infantil.


Hepatitis A is an acute liver disease caused by hepatitis A virus (HAV), an RNA virusof the Picornaviridae's family of fecal-oral transmission. Currently Brazil has a pattern ofintermediate endemicity of the disease. Usually the disease is self-limited and has a benigncourse, but there are severe forms that can cause acute liver failure in 0.01 percent of cases. Besidesto sanitary actions, another important method of prevention is to use inactivated vaccines, butthis is only used to immunize risk groups in Brazil. In native communities, the risk of HAVinfection is high around the world, however, few works address this issue in indigenouscommunities in Brazil. The objective of this study was to evaluate the prevalence of hepatitisA in villages and towns belonging to Apinajé reservation, Tocantinópolis/TO. For this purpose,799 serum samples were analyzed for anti-HAV total being 358 from indigenous villages and441 from local town in eleven geographically separated communities. It was used thecommercial immunoenzymatic kit DiaSorin® brand. The overall prevalence of anti-HAV inthe population studied was 85.5 percent . The locality with the highest prevalence was the GirassolVillage (95.5 percent ). We observed increased prevalence of anti-HAV with an ascending aging ofpopulation, and the lowest prevalence (32.7 percent ) in the younger age group (0-2 years) and a higherprevalence (100 percent ) over 40 years of age.


It is observed that among the indigenous people84.87 percent have anti-HAV reagent and in the towns 85.97 percent , with no difference when comparingthese prevalences. We observed that 39 percent of children under 12 years are bound to acquire thedisease, and up to 5 years, this prevalence rises to 59 percent , so the average population susceptibleto hepatitis A is low as it is between the ranges of 5 to 14 years old. The reserve Apinajé hasintermediate prevalence of anti-HAV, both in villages and in the town. Regarding the trend ofseroconversion of hepatitis A in the villages that occurs most frequently during the transitionfrom preschool to school phase, while in the villages this risk occurs between middle childhoodand adolescence. The prevalence in children and adolescents strengthens implementation ofhepatitis A vaccine included in the childhood schedule could minimize the risks associated withthe disease.


Assuntos
Saúde de Populações Indígenas , Hepatite A/diagnóstico , Hepatite A/epidemiologia , Hepatite A/virologia
3.
Arq. bras. med. vet. zootec ; 64(4): 887-890, Aug. 2012. tab
Artigo em Inglês | LILACS | ID: lil-647689

RESUMO

The objective of this study was to determine the prevalence of Hepatitis A Virus (HAV) in sea food samples in the Isfahan and Shahrekord townships in Iran. From September 2010 to April 2011, a total of 300 samples of fresh fish, shrimp, crab and lobster were obtained from randomly selected retail stores in the Isfahan and Shahrekord townships in Iran. The samples were tested for the presence of HAV using a reverse transcriptase- polymerase chain reaction method. Out of the total number of samples examined, 8 (2.7%) were found to be positive for HAV. This virus was detected in 5% and 1.7% of fresh fish and shrimp, respectively. This study shows the importance of sea food as potential sources of HAV infection in people in Iran.


O objetivo deste estudo foi determinar a prevalência do vírus Hepatitis A (HAV) em amostras de frutos do mar nas cidades de Isfahan e Shahrekord no Iran. De setembro de 2010 a Abril de 2011 um total de 300 amostras de peixe fresco, camarão, caranguejo e lagosta foram obtidas de lojas de varejo aleatoriamente escolhidas nas cidades de Isfahan e Shahrekord no Iran. As amostras foram testadas para presença de HAV usando o método de reação em cadeia em transcriptase reversa. Do total de amostras examinadas, 8 (2.7%) foram positivas para HAV. Este vírus foi detectado em 5% e 1.7% de peixe fresco e camarão, respectivamente. Este estudo mostrou a importância de frutos do mar como fontes potenciais de infecção HAV em pessoas no Iran.


Assuntos
Animais , Frutos do Mar/virologia , Hepatite A/veterinária , Hepatite A/virologia , Infecções/veterinária , Reação em Cadeia da Polimerase Via Transcriptase Reversa/veterinária
4.
Rev. GASTROHNUP ; 12(2, Supl.1): S8-S13, mayo-ago. 2010. tab
Artigo em Inglês | LILACS | ID: lil-645157

RESUMO

La Hepatitis A (HVA), también llamada hepatitis infecciosa, transmitida por alimentos, epidémica,ictericia catarral o epidémica, entre otros, es una enfermedad producida por un agente viral que se trasmite por vía fecal oral y generalmente su curso es autolimitado, aunque, puede progresar ahepatitis fulminante ocasionando la muerte a una proporción pequeña de los infectados. Pertenece al géner o Hepatovir us de la Familia Picornaviridae. La HVA, tiene una distribución universal, aunque con grandes diferencias geográficas en cuanto a su prevalencia, ocurre en forma esporádica y epidémica en todo el mundo, con una tendencia a presentarse en ciclos. La HVA, tiene un periodo de incubación prolongado, entre 15 a 50 días, con un promedio de 29 días, lo que hace difícil relacionar los síntomas con algún alimento o bebida ingerida. El diagnostico de la HVA, se basa en la detección de anticuerpos contra el VHA tipo IgM e IgG. El tratamiento básicamente es de soporte, sintomático y en casos de falla hepática, el trasplante es la única opción. La inmunoglobulina confiere inmunidad pasiva a corto plazo mientras la vacuna provee una protección activa a largo plazo.


Hepatitis A (HVA), also called infectious hepatitis, foodborne, epidemic, or epidemic or catarrhaljaundice, among others, is a disease caused by a viral agent that spreads through fecal-oral routeand usually self-limited course, although fulminant hepatitis can progress to causing death to a small proportion of those infected. Is a Hepatovirus genus of the Picornaviridae Family. The HVA, has a worldwide distribution, but with large geographical differences in its prevalence, occurs in sporadic and epidemic worldwide, with a tendency to occur in cycles. The HVA, has a long incubation period between 15 to 50 days, with an average of 29 days, making it difficult to correlate symptoms with food or drink intake. The diagnosis of HVA was based on the detection of antibodies against HAV IgM and IgG.


Assuntos
Humanos , Masculino , Feminino , Criança , Hepatite A/classificação , Hepatite A/complicações , Hepatite A/diagnóstico , Hepatite A/epidemiologia , Hepatite A/mortalidade , Hepatite A/prevenção & controle , Hepatite A/virologia , Vacinas contra Hepatite A/administração & dosagem , Vacinas contra Hepatite A/classificação , Vacinas contra Hepatite A , Hepatovirus/classificação , Hepatovirus/crescimento & desenvolvimento , Vacinas contra Hepatite A/farmacocinética , Vacinas contra Hepatite A/farmacologia , Vacinas contra Hepatite A
5.
Braz. j. infect. dis ; 13(5): 323-329, Oct. 2009. tab, ilus
Artigo em Inglês | LILACS | ID: lil-544983

RESUMO

Fulminant hepatic failure (FHF) is characterized by massive hepatocellular injury, whose physiopathology is still unclear. Hepatitis B (HBV) is probably the most common viral cause of FHF, while hepatitis A (HAV) virus seem occurs less frequently. However, the host and viral factors that determine the outcome of these infections are poorly understood. In the present study, viral load and genotyping determining regions of HAV and HBV genomes were sequenced. Eight FHF patients and one patient with severe acute hepatitis (SAH) were included. Liver and blood samples were collected during liver transplantation or necropsy procedures. HAV-RNA and HBV-DNA were extracted from serum, biopsy and paraffin liver. Nucleotide sequencing of HAV-RNA was performed from VP1/2A and HBV-DNA from PreS/S region. The amplified samples were quantified by Real-Time PCR. The cases of HAV infection were due to subgenotype IA. The cases of HBV infection were due to genotype A2 and D4. The case of HAV/HBV coinfection was infected by genotype IA and D3. Hepatitis A and B infection were associated with genotypes most prevalent in Brazil. In hepatitis A infection the mean of period evolution was 13 days. In hepatitis B, FHF patients infected by genotype D have a shorter period of evolution than FHF patients infected by genotype A (mean 15 v. 53 days). There was no association with genotype-determining region with the severity of hepatitis, however nucleotide differences and high viral load could be observed among FHF.


Assuntos
Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Vírus da Hepatite A Humana/genética , Hepatite A/virologia , Vírus da Hepatite B/genética , Hepatite B/virologia , Falência Hepática Aguda/virologia , Doença Aguda , Sequência de Bases , Brasil , DNA Viral/análise , Genótipo , Vírus da Hepatite A Humana/imunologia , Hepatite A/complicações , Vírus da Hepatite B/imunologia , Hepatite B/complicações , Dados de Sequência Molecular , Mutação , Filogenia , Reação em Cadeia da Polimerase , RNA Viral/análise , Carga Viral
6.
Mem. Inst. Oswaldo Cruz ; 103(8): 831-835, Dec. 2008. ilus, tab
Artigo em Inglês | LILACS | ID: lil-502305

RESUMO

Hepatitis A virus (HAV) infection is a public health problem worldwide and the virus has been classified into six genotypes. In Brazil, the only genotype that has been found is genotype I, predominately from subgenotype IA. Here, the HAV genotypes were analyzed of 18 isolates circulating between 1996-2001 in Goiânia, state of Goiás, Brazil. Viral RNA was extracted from 18 serum samples and amplified (RT-PCR/nested-PCR), followed by the genomic sequencing of the VP1/2A junction region of the HAV genome. Sequences of 168 nucleotides were compared and analyzed using the BLAST N, Clustal X and PAUP v. 4.10b programs. All samples were classified as genotype I, with 10 belonging to subgenotype IA and eight to subgenotype IB. The subgenotype IA isolates showed greater diversity than the subgenotype IB isolates at the nucleotide level. Elevated identity values were found between isolates obtained in this study and those from other regions of the world, including Brazil, highlighting the high conservation among different isolates of this virus. However, changes in the HAV subgenotype circulation could also be observed during the evaluated period.


Assuntos
Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Adulto Jovem , Vírus da Hepatite A/genética , Hepatite A/virologia , RNA Viral/genética , Sequência de Bases , Brasil , Vírus da Hepatite A/isolamento & purificação , Dados de Sequência Molecular , Filogenia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Adulto Jovem
7.
Mem. Inst. Oswaldo Cruz ; 103(3): 254-258, May 2008. ilus, graf, mapas, tab
Artigo em Inglês | LILACS | ID: lil-485214

RESUMO

From December 1999 to December 2001, many cases of hepatitis A were notified in the county of Belford Roxo involving individuals aged 0 to 79 years. Serum samples were collected to evaluate the prevalence of anti-hepatitis A virus (HAV) antibodies, to detect HAV-RNA and to correlate with possible risk factors of HAV infection. Serum samples were screened by commercial IgM and total anti-HAV antibody ELISA and HAV-RNA was isolated and subsequently amplified by reverse transcription-polymerase chain reaction (RT-PCR) at VP1/2A region, sequenced and analyzed. Total anti-HAV prevalence was 87.9 percent (203/231) and IgM anti-HAV prevalence was 38.7 percent (89/231). Multivariate analysis showed that individuals under 20 years old are risks groups to acquire the infection suggesting that hygienic habits of young subjects are the principal factor of transmission and so they could be the target for vaccine programs. HAV-RNA was amplified from 29 (32.5 percent) IgM anti-HAV positive patients and 26 samples were sequenced and classified into subgenotypes IB (8 isolates) and IA (18 isolates). Isolates classified into subgenotype IB were identical representing one distinct strain. We could observe both subgenotypes circulating during the study which suggests different sources of infection. Prophylactic measures as vaccination strategies added to improvements in hygienic and sanitary conditions would be highly effective to reduction of infection.


Assuntos
Adolescente , Adulto , Idoso , Criança , Pré-Escolar , Feminino , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Surtos de Doenças , Anticorpos Anti-Hepatite A/sangue , Vírus da Hepatite A Humana/classificação , Hepatite A/virologia , Imunoglobulina M/sangue , RNA Viral/análise , Doença Aguda , Brasil/epidemiologia , Ensaio de Imunoadsorção Enzimática , Genótipo , Vírus da Hepatite A Humana/genética , Vírus da Hepatite A Humana/imunologia , Hepatite A/epidemiologia , Filogenia , Prevalência , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Fatores de Risco
8.
The Korean Journal of Laboratory Medicine ; : 371-377, 2008.
Artigo em Coreano | WPRIM | ID: wpr-39343

RESUMO

BACKGROUND: In previous studies, most hepatitis A virus (HAV) isolates had been genotype IA in Korea. Recently, a small number of different genotypes were reported with an upsurge of acute hepatitis by HAV. We investigated the distribution of HAV genotypes. METHODS: RNA was extracted from anti-HAV IgM positive sera which were collected from March 2007 to February 2008 at a tertiary care hospital in Northeastern Seoul, Korea. Nested reverse transcription (RT)-PCR and direct sequencing for VP1/P2A region of the HAV were performed. RESULTS: A total of 699 cases with suspected acute hepatitis were tested for anti-HAV IgM, and positive results were obtained in 56 sera (8.0%), which were collected 2 to 15 days (median, 7 days)after the onset of symptoms. Of the 56 seropositive samples, 52 (92.9%) were positive for HAV RNA, among which 28 isolates (53.8%) belonged to genotype IA and the remaining 24 (46.2%) belonged to genotype IIIA. Both IA and IIIA genotypes were isolated from 6-7 neighboring administrative districts throughout the year without geographic or seasonal restrictions. CONCLUSIONS: Co-circulation of two distinct HAV genotypes (IA and IIIA) was observed from the northeastern Seoul for the year studied.


Assuntos
Adolescente , Adulto , Criança , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto Jovem , Sequência de Aminoácidos , Genótipo , Hepatite A/virologia , Vírus da Hepatite A Humana/classificação , Imunoglobulina M/sangue , Coreia (Geográfico) , Dados de Sequência Molecular , Filogenia , RNA Viral/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de DNA , Proteínas Estruturais Virais/genética
9.
Acta gastroenterol. latinoam ; 36(4): 182-189, dic. 2006. tab, graf
Artigo em Espanhol | LILACS | ID: lil-459130

RESUMO

La infección por el virus de hepatitis A (HAV) es endémica en Argentina. El uso de técnicas moleculares permitió extender la detección del RNA del HAV en sueroy heces en pacientes con diferentes presentaciones clínicas. Comparamos la sensibilidad del protocolo de RT-PCR que usamos con cebadores dirigidos a distintas regiones del genoma, resultando la detección de la región VP3 C terminal la más sensible. Se obtuvieron prospectivamente muestras de suero y materia fecal de 20 niños con hepatitis aguda autolimitada por HAV. El RNA del HAV fue detectado en 18/20 niños en muestras basales y en 19/20 sumando una muestra posterior. El RNA del HAV fue detectable en 9/20 acientes hasta 30 días en suero; en materia fecal en 2/20 hasta 60 días y en 1/20 hasta 90 días. La secuencia genómica para la región VP1/2A en 8 muestras demostró que todas pertenecían al subgenotipo IA, aunque eran diferentes entre sí. Solo en 1/11 niños con falla hepatica fulminante fue posible la detección del RNA del HAV utilizando la región VP3 C terminal y el genotipo fue I. La reciente introducción de la vacunación universal en niños de 1 año de edad en Argentina podría disminuir drásticamente la circulación del virus, emergiendo nuevas fuentes de infección y permitiendo la introducción de nuevos genotipos. Las técnicas moleculares aplicadas al estudio de la historia natural de la infección y a la vigilancia epidemiológica contribuyenal control y la toma de decisiones eficientes en políticas de Salud Pública.


Hepatitis A virus (HAV) infection is endemic in Argentina. Molecular tools have allowed HAV RNA detection to be extent to sera and feces from patients with different clinical backgrounds. We compare the sensitivity of the RT-PCR protocol we follow using primers targeting different genomic regions and VP3 C terminal was the most sensitive. Sequential sera and fecal samples were obtained from 20 children with acute self limited Hepatitis A. HAV RNA was detectable in 18/20 children if sera and stool specimens were collected at the onset of symptoms and in 19/20 if a later sample was considered. HAV RNA was detectable in serum from 9/20 patients until day 30 and in feces from 2 patients until day 60 and until day 90 in one. Genomic sequences from VP1/2A region in 8 samples showed they all belong to subgenotype IA although they were different between them. HAV RNA was detectable only in 1/11 sera from children with acute liverfailure when VP3 C terminal fragment was searched and it belonged to genotype I. Universal vaccination in one year old children was recently implemented in Argentinaand it will dramatically enable the decrease of the viral circulation, making new sources of infection emerge and allowing the introduction of new genotypes. The application of molecular tools to the study of the natural history of infection and to the epidemiologicsurveillance may contribute to efficient control and lead to rational decisions in public health policies.


Assuntos
Humanos , Masculino , Feminino , Lactente , Pré-Escolar , Criança , Adolescente , Fezes/virologia , Hepatite A/diagnóstico , Hepatovirus/isolamento & purificação , Viremia/virologia , Eliminação de Partículas Virais , Doença Aguda , Hepatite A/complicações , Hepatite A/virologia , Hepatovirus/genética , Falência Hepática Aguda/sangue , Falência Hepática Aguda/virologia , Dados de Sequência Molecular , Sondas de Oligonucleotídeos , Estudos Prospectivos , RNA Viral/análise , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Sensibilidade e Especificidade , Fatores de Tempo
10.
Braz. j. med. biol. res ; 39(7): 873-881, July 2006. ilus, tab
Artigo em Inglês | LILACS | ID: lil-431558

RESUMO

The Northeast region is the location of most cases of acute hepatitis A virus (HAV) in Brazil. In the present study, the genotypes of HAV strains from Pernambuco State, one of most populous states in the Northeast region, were characterized. Blood samples positive for anti-HAV IgM from 145 individuals (mean age = 29.1 years), collected during 2002 and 2003, were submitted to nested RT-PCR for amplification of the 5'non-translated region (5'NTR) and VP1/2A regions of the HAV genome. The VP1/2A and 5'NTR regions were amplified in 39 and 21 percent of the samples, respectively. Nucleotide sequencing was carried out in 46 percent of VP1/2A and in 53 percent of 5'NTR isolates. The identity in nucleotide sequence of the VP1/2A region ranged from 93.6 to 100.0 percent. Phylogenetic analysis of the VP1/2A sequences showed that 65 percent belong to sub-genotype IA and 35 percent to sub-genotype IB. Co-circulation of both sub-genotypes was observed in the two years studied. Distinct clusters of highly related sequences were observed in both sub-genotypes, suggesting endemic circulation of HAV strains in this area. In the 5'NTR isolates, 92.7-99.2 percent identity was observed and two isolates presented one deletion at position 413. Phylogenetic analysis showed that genotype IA strains cluster in the tree in the same way as genotype IB strains, but one IIIA isolate from Spain clusters with genotype IB strains. These results do not allow us to state that 5'NTR could be used to genotype HAV sequences. This is the first report of co-circulation of sub-genotypes IA and IB in this region, providing additional information about the molecular epidemiology of HAV strains in Brazil.


Assuntos
Humanos , Masculino , Feminino , Adulto , /genética , Vírus da Hepatite A/genética , Hepatite A/virologia , RNA Viral/análise , Proteínas Estruturais Virais/genética , Sequência de Bases , Brasil , Genoma Viral , Genótipo , Vírus da Hepatite A/classificação , Vírus da Hepatite A/isolamento & purificação , Técnicas de Amplificação de Ácido Nucleico , Filogenia , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Análise de Sequência de RNA
11.
Braz. j. med. biol. res ; 37(12): 1779-1787, Dec. 2004. ilus, tab, graf
Artigo em Inglês | LILACS | ID: lil-388062

RESUMO

The epidemiology of hepatitis A virus (HAV) infection is shifting from high to intermediate endemicity in Brazil, resulting in increased numbers of susceptible individuals and a greater potential for the emergence of outbreaks. Universal vaccination against HAV has been recommended for children, but updated sero-epidemiological data are necessary to analyze the level of natural immunity and to identify candidates for preventive measures. In addition, more molecular studies are necessary to characterize the genotypes involved in HAV infections and outbreaks. Sera from 299 school children (5-15 years old) and 25 school staff members, collected during an outbreak of HAV at a rural public school in June 2000, were tested for IgM and total anti-HAV antibodies (ELISA). Viral RNA was amplified by RT-PCR from anti-HAV IgM-positive sera and from 19 fecal samples. Direct nucleotide sequencing of the VP1/2A region was carried out on 18 PCR-positive samples. Acute HAV infection was detected by anti-HAV IgM in 93/299 children and in 3/25 adult staff members. The prevalence of total anti-HAV antibodies in IgM-negative children under 5 years of age was only 10.5 percent. HAV-RNA was detected in 46 percent IgM-positive serum samples and in 16 percent stool samples. Sequence analysis showed that half the isolates belonged to subgenotype IA and the other half to IB. On the basis of these data, mass vaccination against HAV is recommended without prevaccination screening, especially for children before they enter school, since nearly 90 percent of the children under 5 years were susceptible. Molecular characterization indicated the endemic circulation of specific HAV strains belonging to subgenotypes IA and IB.


Assuntos
Humanos , Pré-Escolar , Criança , Adolescente , Adulto , Pessoa de Meia-Idade , Variação Genética , Vírus da Hepatite A Humana/genética , Hepatite A/virologia , Brasil/epidemiologia , Surtos de Doenças , Anticorpos Anti-Hepatite A/sangue , Hepatite A/epidemiologia , Imunoglobulina G/sangue , Filogenia , RNA Viral/genética , População Rural , Estudos Soroepidemiológicos
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