RESUMO
Argentina exhibits low serological prevalence for Hepatitis B virus (HBV); however, occult hepatitis B infection (OBI) has been reported in blood donors, Amerindians and individuals coinfected with hepatitis C virus (HCV), and/or human immunodeficiency virus (HIV). The aim of this study was to analyze the genetic diversity of HBV and to evaluate serological marker associations and coinfections with HCV and HIV in patients attending and treated in a public hospital in the province of Buenos Aires, Argentina. A total of 189 HBV reactive samples (HBsAg and/or anti-HBc) were analyzed for HBV DNA characterization. All reactive samples were tested for anti-HCV and HIV-antigen/antibody using CMIA assays. Thirty-six samples exhibited detectable HBV DNA, 7 of which were OBI. HBV sequences were classified as subgenotypes A1, A2, B2, D3, F1b, F3 and F4. Mutations related to the ability to escape the host's immune response, resistance to antiviral therapy and progression to disease were found in patients, partly due to the variable sensitivity of HBsAg, the reverse transcriptase, the basal core promoter and the preCore. HCV and HIV prevalence was 10% and most of the genotypes found in the sequences were genotype 1 and B/F recombinant subtype, respectively. Of the total samples analyzed, 7 exhibited coinfections. This study shows the frequency of OBI, subgenotype distribution, HBV mutations and coinfections, which may have important clinical implications in public hospital patients. Planned prevention, detection and treatment adherence are needed to reduce transmission and morbidity in vulnerable populations.
Assuntos
Coinfecção/genética , Hepatite B Crônica/genética , Hepatite B/genética , Hepatite C/genética , Adolescente , Adulto , Idoso , Argentina/epidemiologia , Doadores de Sangue , Coinfecção/sangue , Coinfecção/tratamento farmacológico , Coinfecção/virologia , Farmacorresistência Viral/genética , Feminino , Genótipo , Infecções por HIV/sangue , Infecções por HIV/genética , Infecções por HIV/virologia , Hepacivirus/genética , Hepacivirus/patogenicidade , Hepatite B/sangue , Hepatite B/tratamento farmacológico , Hepatite B/virologia , Anticorpos Anti-Hepatite B/sangue , Anticorpos Anti-Hepatite B/imunologia , Antígenos de Superfície da Hepatite B/sangue , Antígenos de Superfície da Hepatite B/genética , Antígenos de Superfície da Hepatite B/imunologia , Vírus da Hepatite B/genética , Vírus da Hepatite B/patogenicidade , Hepatite B Crônica/sangue , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/virologia , Hepatite C/sangue , Hepatite C/tratamento farmacológico , Hepatite C/virologia , Hospitais Públicos , Humanos , Masculino , Pessoa de Meia-Idade , Mutação/genética , Sangue Oculto , Adulto JovemRESUMO
The intragroup antigenic diversity of the G glycoprotein of 226 human respiratory syncytial virus (HRSV) strains isolated in Buenos Aires (Argentina) and Santiago (Chile) between 1995 and 2002 was evaluated by ELISA with a panel of 14 anti-G monoclonal antibodies (MAbs). Out of 226 strains characterized, 172 (76%) belonged to group A and 54 (24%) to group B. Strains from both groups cocirculated throughout the study period in both countries, except in 1996, 2000, and 2002 when only group A strains were isolated. Within group A 23 different antigenic patterns were found as defined by the combination of reactivities with eight strain-specific anti-G MAbs. These antigenic patterns showed different behavior regarding their circulation. Some major patterns were observed in most years with variable proportions; other minor patterns were present in low proportions during 1 or 2 years and then were apparently replaced by new patterns. Some antigenic patterns occurred both in Argentina and Chile during the same epidemics. Since no strain-specific MAbs were available for group B, we could not evidence the antigenic variability within group B. These are the first data on antigenic characterization of HRSV strains isolated in Argentina and Chile. It is shown that the ELISA with MAbs directed against the G protein of RSV is a valuable tool. These results will also provide useful information for further studies to evaluate the antigenic variability of HRSV strains in relation with genetic characteristics.
Assuntos
Antígenos Virais/genética , Infecções por Vírus Respiratório Sincicial/epidemiologia , Infecções por Vírus Respiratório Sincicial/virologia , Vírus Sincicial Respiratório Humano/genética , Variação Antigênica , Argentina/epidemiologia , Pré-Escolar , Chile/epidemiologia , Humanos , LactenteRESUMO
Human metapneumovirus (hMPV) is a virus, which was first associated with acute lower respiratory infection in children but is detected currently in all age groups. Clinical symptoms are similar to those described for respiratory syncytial virus (RSV) infections, ranging from mild respiratory illness to severe bronchiolitis and pneumonia in children. To date, no cases of hMPV have been reported in Argentina. In this study, 440 respiratory samples obtained during the period 1998-2002 from children under 5 years old with acute respiratory infection were evaluated. Routine detection for RSV, adenovirus, influenza, and parainfluenza was undertaken by immunofluorescent assay. Of the samples negative for these viruses, only 100 were available. All these samples were tested for hMPV by RT-PCR using primers for the L gene. Eleven out of 100 (11%) respiratory samples were positive for hMPV by RT-PCR. A higher frequency of detection was observed in spring. hMPV was detected in all the years studied, except in 2001. Ten out of 11 children positive for hMPV were hospitalized. Median age was 5 months. Of seven patients, five (71%) required oxygen supplementation. The most frequent diagnosis was bronchiolitis (86%), sometimes accompanied by conjunctivitis and otitis media. The present study showed that hMPV was associated with acute lower respiratory infections in children in Buenos Aires, Argentina. This evidence strongly suggests that hMPV is a common pathogen with a wide geographical distribution, which should be included in the routine diagnosis of respiratory viruses in young children.
Assuntos
Metapneumovirus/isolamento & purificação , Infecções por Paramyxoviridae/epidemiologia , Infecções por Paramyxoviridae/virologia , Infecções Respiratórias/epidemiologia , Infecções Respiratórias/virologia , Argentina/epidemiologia , Pré-Escolar , Humanos , Lactente , Recém-Nascido , Metapneumovirus/genética , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Estações do Ano , Proteínas Virais/genéticaRESUMO
In immunocompromised patients, diagnosis of Cytomegalovirus (CMV) active infection is of utmost importance for the initiation, monitoring and ending of antiviral therapy. Therefore, the presence of viral replication should be demonstrated. Isolation in tissue culture is one of the standard methods. The objective of the present paper was to compare two isolation procedures for CMV: conventional cell culture (CC) and rapid shell vial (SV) assay in human fibroblasts. A total of 584 clinical samples were studied between 1991 and 1998. CMV was isolated in 14.4 per cent of the samples, 11.8 per cent of which were positive by SV and 7.7 per cent by CC. Out of 84 positive samples, concordance between both methods was observed in 36 per cent of the cases. We found that 46 per cent of the samples were positive only by SV, while 18 per cent were positive only by CC. The average time required for obtaining the results by CC was 22.6 +/- 2.3 days. Out of the 69 samples positive by SV, 43 per cent were already positive after 24 hours and the rest after 48 hours. These results indicate that SV was more sensitive and rapid than CC. The main advantage of CC, despite its time-consuming process, is the ability to recover the viral strain for both antiviral susceptibility phenotypical tests and strain characterization. Furthermore, in this study, absence of CC would have resulted in the loss of 18 per cent of the positive diagnoses. In conclusion, simultaneous use of both methods is suggested in order to obtain a rapid result and the highest sensitivity.
Assuntos
Humanos , Citomegalovirus , Infecções por Citomegalovirus , Sensibilidade e Especificidade , Cultura de Vírus , Replicação ViralRESUMO
In immunocompromised patients, diagnosis of Cytomegalovirus (CMV) active infection is of utmost importance for the initiation, monitoring and ending of antiviral therapy. Therefore, the presence of viral replication should be demonstrated. Isolation in tissue culture is one of the standard methods. The objective of the present paper was to compare two isolation procedures for CMV: conventional cell culture (CC) and rapid shell vial (SV) assay in human fibroblasts. A total of 584 clinical samples were studied between 1991 and 1998. CMV was isolated in 14.4 per cent of the samples, 11.8 per cent of which were positive by SV and 7.7 per cent by CC. Out of 84 positive samples, concordance between both methods was observed in 36 per cent of the cases. We found that 46 per cent of the samples were positive only by SV, while 18 per cent were positive only by CC. The average time required for obtaining the results by CC was 22.6 +/- 2.3 days. Out of the 69 samples positive by SV, 43 per cent were already positive after 24 hours and the rest after 48 hours. These results indicate that SV was more sensitive and rapid than CC. The main advantage of CC, despite its time-consuming process, is the ability to recover the viral strain for both antiviral susceptibility phenotypical tests and strain characterization. Furthermore, in this study, absence of CC would have resulted in the loss of 18 per cent of the positive diagnoses. In conclusion, simultaneous use of both methods is suggested in order to obtain a rapid result and the highest sensitivity. (Au)