RESUMEN
Eight cases of de novo hepatitis C virus (HCV) infection in a haemodialysis unit in Rio de Janeiro, Brazil, were retrospectively studied. HCV viraemia was demonstrated by RT nested PCR in seven of the seroconverters. Genotyping showed that six patients were infected with a genotype 1b strain and one with a genotype 1a strain. A phylogenetic analysis of nucleotide sequences of the HCV core region revealed that five of the six 1b isolates form a separate cluster when compared with other 38 HCV 1b core sequences randomly chosen from the GenBank. The revealed sequence similarities indicated the nosocomial spread of a single HCV strain within the unit. To investigate whether the patients infected with the same viral isolate display similar patterns of antibody response to individual proteins, serial serum samples were examined. A line immunoassay for qualitative and semi-quantitative determination of specific antibodies against recombinant and synthetic HCV antigens was employed. Despite infection with the same virus strain, the patients sera demonstrated different patterns of reactivity against individual structural and nonstructural HCV proteins immediately after seroconversion. For each patient, however, antibody responses remained mostly stable throughout the follow-up of 8 to 24 months.
Asunto(s)
Anticuerpos contra la Hepatitis C/sangre , Hepatitis C/inmunología , Diálisis Renal , Genotipo , Hepacivirus/genética , Hepacivirus/inmunología , Hepacivirus/aislamiento & purificación , Hepatitis C/sangre , Hepatitis C/virología , Humanos , Datos de Secuencia Molecular , Filogenia , Estudios Prospectivos , ARN Viral/análisis , Proteínas Recombinantes/inmunología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Homología de Secuencia de Ácido Nucleico , Proteínas del Núcleo Viral/genética , Proteínas del Núcleo Viral/inmunología , Proteínas no Estructurales Virales/inmunología , Proteínas Estructurales Virales/inmunología , ViremiaRESUMEN
A recent report has described the molecular cloning and characterization of a novel, single-stranded DNA virus, named TT virus (TTV), which was present in the sera of Japanese patients with posttransfusion hepatitis of unknown etiology [Okamoto et al. (1998) Hepatology Research 10:1-16]. Using a nested polymerase chain reaction assay, sera from Brazilian patients with acute non A-C hepatitis and blood donors were examined for the presence of TTV DNA sequences. Thirty-seven of 52 (71%) patients with acute non A-C hepatitis and 45 of 72 (62%) blood donors were found to have TTV sequences in their sera. Such a high proportion in blood donors indicated that TTV infection is common in the general Brazilian population. Partial nucleotide sequences (326 bases in open reading frame 1) from seven isolates were determined. By phylogenetic analysis, four TTV strains were classified into the genomic subgroup G1a described previously. The three others belonged to subgroup G1b. Sequence homologies between strains belonging to a same subgroup were 92.9-99.1%, whereas homologies of 85.9-90.2% were calculated between isolates from different subgroups.
Asunto(s)
Donantes de Sangre , Virus ADN , Hepatitis Viral Humana/epidemiología , Adolescente , Adulto , Anciano , Secuencia de Bases , Brasil/epidemiología , Niño , Virus ADN/clasificación , Virus ADN/genética , Virus ADN/aislamiento & purificación , ADN Viral , Femenino , Hepatitis Viral Humana/sangre , Hepatitis Viral Humana/virología , Humanos , Lactante , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Filogenia , PrevalenciaRESUMEN
The recently discovered GBV-C/hepatitis G virus (GBV-C/HGV) has been shown to be parenterally transmitted. The occurrence of community-acquired GBV-C/HGV infections has also been reported. In order to study the variations with age of the GBV-C/HGV prevalence, sera from 268 individuals without liver disease, aged 0-80 years, and living in the city of Rio de Janeiro, Brazil, were tested by reverse transcription-nested polymerase chain reaction for the presence of GBV-C/HGV RNA. Age-specific seroprevalence was low (2.3%) among children under the age of 10, reached a maximum of 18% in young adults (21-30 years), and declined in older age groups. Among 170 blood donors aged 18-60, the rate of individuals with antibodies against the viral envelope E2 protein increased with age, from about 6% between the ages of 18 and 24 to about 35% for individuals from the age of 43 to 60. The results suggest that sexual transmission of GBV-C/HGV might occur and that the virus could be eliminated after a long period of infection. The nucleotide sequences of GBV-C/HGV genome fragments, 422 base pairs (bp) in the E2 region and 354 bp in the nonstructural 5 region, were determined for 11 and 31 isolates, respectively. Phylogenetic tree based on concatenated E2 + NS5 sequences showed that Brazilian strains belonged to three clusters, two of which were previously characterized as genotypes 1 and 2.
Asunto(s)
Flaviviridae/genética , Hepatitis Viral Humana/virología , Adolescente , Adulto , Factores de Edad , Brasil/epidemiología , Niño , Variación Genética , Hepatitis Viral Humana/epidemiología , Hepatitis Viral Humana/transmisión , Humanos , Persona de Mediana Edad , Datos de Secuencia Molecular , Filogenia , Reacción en Cadena de la Polimerasa , PrevalenciaRESUMEN
Since the identification of the new human virus, GB virus C (GBV-C)/hepatitis G-virus (HGV), in 1995/1996, reverse transcription polymerase chain reaction remained the sole available diagnostic tool for GBV-C/HGV infection. Recently, a serologic test based on the detection of antibodies to the putative envelope protein 2 (anti-E2) has been introduced. We used this assay for a seroepidemiological survey including 3,314 healthy individuals from different parts of the world, 123 patients from Germany who were suspected to have an increased risk of acquiring GBV-C/HGV infection, 128 multiple organ donors, and 90 GBV-C/HGV RNA positive persons. In European countries, anti-E2 seropositivity ranged from 10.9% (Germany) to 15.3% (Austria). In South Africa (20.3%) and Brazil (19.5%), even higher anti-E2 prevalence rates were recorded. In Asian countries like Bhutan (3.9%), Malaysia (6.3%), and the Philippines (2.7%), anti-E2 positivity was significantly lower. GBV-C/HGV anti-E2 prevalence in potential "risk groups," i.e., patients on hemodialysis and renal transplant recipients, did not vary significantly from anti-E2 seroprevalence in German blood donors. Anti-E2 and GBV-C/HGV RNA were found to be mutually exclusive, confirming the notion that anti-E2 has to be considered as a marker of past infection.