ABSTRACT
The serological pattern, "anti-HBc alone", characterized by the presence of antibodies against the core antigen of hepatitis B virus (anti-HBc) as the only marker of hepatitis B, is not rare in a diagnostic setting. Depending on the prevalence of HBV infection and the patient group investigated, 1-31% of positive anti-HBc results are isolated positive findings. Anti-HBc alone is frequently observed in intravenous drug addicts, HIV-infected individuals, patients who are coinfected with HBV and hepatitis C virus, and pregnant women. However, it is not clear how this profile should be interpreted. Several studies have shown that anti-HBc alone is not only compatible with acute and resolved HBV infection but also with chronic infection. The reasons for the lack of HBsAg and anti-HBs in anti-HBc-alone individuals are not clear, but several mechanisms and possibilities have been suggested that could explain this phenomenon, some of which are delineated in this article.
Subject(s)
Hepatitis B Antibodies/blood , Hepatitis B Core Antigens/immunology , Hepatitis B/diagnosis , Female , Hepatitis B/immunology , Humans , Male , PregnancyABSTRACT
Group A rotaviruses (RVA) are the main causing agents of acute gastroenteritis worldwide, having a great impact on childhood mortality in developing countries. The objective of this study was to identify RVA-positive fecal samples with mixed P genotypes by hemi-nested reverse transcriptase-polymerase chain reaction (RT-PCR), followed by sequencing confirmation. Our results showed that, from the 81 RVA-positive samples, 25 were positive for more than one P genotype by hemi-nested RT-PCR. Of these 25 samples, 12 (48%) had their mixed P genotypes confirmed by sequencing and, from these, 10 were identified as P[6]P[8], one as P[4]P[6], and one as P[4]P[6]P[8]. Our results confirm the occurrence of RVA mixed infections among children in Brazil and reinforce the importance of the constant monitoring of RVA circulating strains for the efficacy of control/prevention against these agents.
Subject(s)
Gastroenteritis/virology , Rotavirus Infections/virology , Rotavirus/classification , Rotavirus/genetics , Brazil , Child , Feces/virology , Female , Genotype , Humans , Male , Phylogeny , Reverse Transcriptase Polymerase Chain Reaction/methods , Rotavirus/isolation & purification , Sequence Analysis, DNA , Sequence HomologyABSTRACT
The occurrence of Aichi virus, a picornavirus associated with acute gastroenteritis, has so far only been described in Asian countries. This study reports the first finding of Aichi virus in clinical specimens from Germany and Brazil. The nucleotide sequences of both a German and a Brazilian isolate were determined, analyzed, and compared to known Aichi sequences. The German strain turned out to be a member of genogroup A, while the Brazilian belonged to genogroup B. For a primary assessment of the epidemiological importance of Aichi virus in Germany, a panel of 485 German serum samples was screened for antibody to Aichi virus, and a seroprevalence of 76% was found.
Subject(s)
Gastroenteritis/virology , Genome, Viral/genetics , Picornaviridae Infections/virology , Picornaviridae/genetics , Picornaviridae/isolation & purification , RNA, Viral/genetics , Antibodies, Viral/blood , Base Sequence , Brazil , Gastroenteritis/epidemiology , Genotype , Germany , Humans , Molecular Sequence Data , Phylogeny , Picornaviridae/classification , Picornaviridae Infections/epidemiology , Sequence Analysis, DNA , Seroepidemiologic StudiesABSTRACT
Human astroviruses (HAstV) are recognized as an important cause of gastroenteritis in young children worldwide. This study describes the molecular characteristics of astroviruses isolated in Brazil, using RT-PCR and molecular sequencing of segments of all three viral ORFs. Genetic analysis of a 348-nucleotide segment from ORF 2 demonstrated that the Brazilian isolates belong to HAstV genotypes 1 to 5 and 8. ORF 1b sequences displayed a high degree of nucleotide identity even between different genotypes, which disfavours HAstV genotyping in this region. ORF 1a sequence analysis classified all Brazilian samples as genogroup A. The complete sequences of HAstV genotype 4 (putative serotype 4) and genotype 5 (putative serotype 5) were determined for the first time.
Subject(s)
Astroviridae Infections/virology , Mamastrovirus/classification , Mamastrovirus/genetics , Base Sequence , Brazil , Child , Child, Preschool , Genotype , Humans , Mamastrovirus/isolation & purification , Molecular Sequence Data , Open Reading Frames , Phylogeny , RNA, Viral/genetics , Reverse Transcriptase Polymerase Chain Reaction , Sequence HomologyABSTRACT
Objetivos: Determinar la seroprevalencia del citomegalovirus en gestantes e identificar a las infectadas agudamente o reactivadas. Material y métodos: Se investigó la seroprevalencia de los anticuerpos IgG e IgM en 323 gestantes del Hospital Materno Infantil de Goiânia, por enzimoinmunoanálisis (ELISA), y de éstas, 77 por la prueba de avidez de la IgG para la fase serológica con IgM ausente, escogidas al azar. Resultados: La media de edad ± DE fue de 24,55 ± 6,80 años, y de 23,09 ± 8,78 semanas de edad gestacional. El 98,76% presentaron IgG y el 0,62% además la IgM. El 31,17% presentó baja avidez y el 68,83%, elevada. Conclusiones: De las gestantes estudiadas, el 98,76% presentó infección crónica y el 0,62%, infección aguda. En las investigadas con la prueba de avidez de la IgG, el 31,17% se encontraba en la fase aguda de infección por citomegalovirus, con lo que son necesarios exámenes más sensibles de detección en esta fase debido a la relación con una mayor afección congénita
Objectives: To determine the seroprevalence of cytomegalovirus in pregnant women and to identify those with acute or reactivated infections. Materials and methods: The seroprevalence of IgG and IgM antibodies in 323 pregnant women in the Maternity Hospital of Goiânia was studied using ELISA. Seventy-seven samples were randomly selected to undergo the IgG avidity test for the serological stage without IgM. Results: The mean ± SD age was 24.55 ± 6.80 years and the mean ± SD gestational age was 23.09 ± 8.78 weeks. IgG antibodies were identified in 98.76% and IgM antibodies in 0.62%. Low avidity was found in 31.17% and high avidity was found in 68.83%.Conclusions: Among the pregnant women studied, 98.76% had chronic infection and 0.62% had acute infection. The results of the IgG avidity test revealed that 31.17% were in the acute stage of cytomegalovirus infection. This finding highlights the need for more sensitive detection methods in the acute phase, due to the greater possibility of congenital infection
Subject(s)
Female , Pregnancy , Adult , Adolescent , Humans , Cytomegalovirus Infections/epidemiology , Cytomegalovirus/isolation & purification , Seroepidemiologic Studies , Pregnancy Complications, Infectious/epidemiology , Immunoglobulin G , Immunoglobulin M , Infectious Disease Transmission, Vertical/prevention & controlABSTRACT
Fecal samples positive for rotavirus group A ( n=120) were analyzed by enzyme immunoassay-monoclonal antibody (EIA-MAb) serotyping and/or reverse transcription/multiplex polymerase chain reaction (PCR) amplification to determine the prevalence of the [P] and G genotypes. The most prevalent G genotype/serotype detected was G1 (76.7%), followed by G2 (5.0%). Six samples were characterized as G9 by multiplex PCR, and one sample was characterized as G3 by EIA-MAb. The combinations of [P] and G genotypes found were P[8] and G1 (20.8%), P[6] and G1 (10.8%), P[6] and G9 (4.2%), P[8] and G2 (1.7%), and P[6] and G2 (0.8%). The diversity of rotavirus group A [P] and G genotypes/serotypes reinforces the need for continuous characterization of rotaviruses circulating in populations in Brazil.
Subject(s)
Rotavirus/isolation & purification , Brazil/epidemiology , Child, Preschool , Diarrhea/epidemiology , Diarrhea/prevention & control , Diarrhea/virology , Genotype , Hospitalization , Humans , Reverse Transcriptase Polymerase Chain Reaction , Rotavirus/classification , Rotavirus/genetics , Rotavirus Infections/epidemiology , Rotavirus Infections/virology , SerotypingABSTRACT
The G genotyping of 74 group A rotavirus samples was done by RNA-DNA hybridization (dot-blot) using oligonucleotide probes for the VP7 gene region of the human rotavirus serotypes/genotypes 1, 2, 3 and 4. Thirty-one samples could be genotyped by dot-blot showing the following results: G1 = 16, G4 = 6, G3 = 5, and G2 = 4. The data show circulation of genotypes G1-G4 and the predominance of G1. The knowledge of genotypes provides important information concerning rotavirus circulation in Central Brazil
Subject(s)
Humans , Child , Rotavirus/genetics , Brazil , Diarrhea/virology , Genotype , Nucleic Acid Hybridization , Oligonucleotide Probes , Rotavirus/classificationABSTRACT
Um estudo seroepidemiologico para o virus da hepatite A (VHA), investigando os marcadores de infeccao passada (anti-VHA total anti-IgG e IgM) e infeccao recente (anti-VHA IgM), foi realizado entre 1991 e 1992, em criancas de creche de Goiania-Brasil central. Das 310 criancas com idade entre 03 meses e 09 anos, 69,7 por cento mostraram soropositividade ao anti-VHA total, sendo 60 por cento, na faixa etaria entre 1 e 3 anos. A prevalencia do marcador anti-VHA IgM foi de 3,2 por cento visto em idade de 1-4 anos e com distribuicao uniforme nas 10 creches estudadas. Entre as variaveis sociodemograficas estudadas, apenas o tempo de frequencia das criancas nas creches, igual ou superior a um ano, mostrou, em analise multivariada ajustada para idade, um risco de 4,7 vezes maior quando comparado com o periodo de um mes (LC 95 por cento 2,3-9,9)...
Subject(s)
Humans , Male , Female , Infant , Child, Preschool , Child , Child Day Care Centers , Hepatitis A/epidemiology , Risk Factors , Brazil , Hepatitis A/immunology , Serologic TestsABSTRACT
Um estudo soro epidemiológico, para anticorpos contra o virus da hepatite A (anti-VHA total-IgM e IgG), foi realizado no período de 1991-1992, em 397 "meninos de/na rua" em Goiânia. Destes, 313 apresentavam vínculo familiar e desenvolviam, em sua maioria, atividades de trabalho informal, enquanto que 84 nao possuiam vínculo familiar e se encontravam na rua ou em Instituiçoes do Governo Estadual. A taxa média de prevalência foi de 90,4 por cento, variando de 80,0 por cento a 92,9 por cento, sem contudo apresentar diferença estatística significante relativa à idade (7-21). Também nao se evidenciou qualquer diferença quando este grupo foi estratificado para presença ou ausência de vínculo familiar ou mesmo quando analisado em relaçao a outras variáveis sócio-demográficas. Estes dados sugerem que a hepatite A é endêmica na populaçao de baixa condiçao sócio-econômica da regiao e que nesta faixa etária a maioria dos indivíduos já adquiriu a infecçao. Outras investigaçoes em grupos e camadas sociais diferentes sao necessárias a fim de parametrar estratégias vacinais em países subdesenvolvidos.
Subject(s)
Humans , Male , Female , Child , Hepatitis A/epidemiology , Homeless Youth , Brazil , Hepatitis Antibodies/blood , Hepatitis A/blood , Prevalence , Seroepidemiologic Studies , Hepatitis A Virus, Human/immunologySubject(s)
Humans , Male , Female , Infant , Child, Preschool , Child , Adolescent , Adult , Middle Aged , Hepatitis C/transmission , Brazil , Enzyme-Linked Immunosorbent Assay , Hepatitis C/epidemiology , Hepatitis C/genetics , Hepatitis C/immunologyABSTRACT
Amostras de soro de grupos populacionais dos Estados do Pará e Goiás, coletados ente 1974 e 1980, foram testadas (ELISA, imunofluorescência e immunoblot) para a presença de anticorpos contra o vírus da imunodeficiência humana tipo-1 (HIV-1). O objetivo principal foi de se mapear epidemiologicamente a ocorrência deste vírus em um período anterior a detecçäo da presente epidemia. Quatro amostras dos índios Xicrin foram positivas pelo teste ELISA, porém näo foram confirmadas pelos demais testes. Os resultados negativos sugerem a ausência de circulaçäo do HIV-1, nos grupos testados, no período pré-1980
