RESUMEN
BACKGROUND: Acute respiratory infections are a principal cause of illness and mortality especially in young children worldwide. OBJECTIVES: To study the epidemiology and seasonality of viral respiratory infections in hospitalized children (under the age of 16) between September 2012 and August 2016. STUDY DESIGN: Nasopharyngeal swabs or aspirates were collected from 3199 symptomatic patients and then screened with a routine multiplex PCR assay. RESULTS: Respiratory viruses were detected for 1624 (50.8%) of the 3199 children in the study population. Of these, 210 (13.3%) were positive for two viruses, 28 (1.7%) were positive for three, and 3 (0.2%) were positive for four. The viral profile varied with age. Some viruses were significantly more frequent in children under the age of 1 month (such as human respiratory syncytial virus (pâ¯<â¯0.0001)), whereas others were significantly more frequent in children over that age (such as influenza viruses (pâ¯<â¯0.0001) and adenoviruses (pâ¯=â¯.0006)). The distribution of viruses is variable over the year depending on the species. However, the atmospheric temperature was rarely found to be a limiting factor in the circulation of respiratory viruses. CONCLUSIONS: our results constitute a detailed description of the distribution of respiratory viruses among hospitalized children over four consecutive years. Our data notably highlight the persistence of non-enveloped viruses and some enveloped viruses throughout the year-regardless of temperature variations.
Asunto(s)
Hospitalización , Infecciones del Sistema Respiratorio/epidemiología , Infecciones del Sistema Respiratorio/virología , Estaciones del Año , Virus/aislamiento & purificación , Enfermedad Aguda , Adolescente , Factores de Edad , Niño , Preescolar , Coinfección/epidemiología , Coinfección/virología , Francia/epidemiología , Humanos , Lactante , Recién Nacido , Reacción en Cadena de la Polimerasa Multiplex , Estudios Retrospectivos , Virus/clasificaciónRESUMEN
This study compared the performance of 3 automated immunoassays, Architect® (Abbott), Immulite® (Siemens) and Liaison® (Diasorin), for Epstein-Barr virus (EBV) serology. Ninety-one serum samples collected in Amiens University Hospital were analyzed for the presence of Viral Capsid Antigen (VCA) IgG and IgM and Epstein-Barr Nuclear Antigen (EBNA) IgG. The agreement between the 3 assays was calculated for each marker individually and for determination of the EBV profile, based on interpretation of the combination of these 3 EBV markers. Although similar results were obtained with Architect® and Liaison®, several discordant results were observed with Immulite®, particularly for EBNA IgG. A large number of EBNA IgG-positive results were observed, which interfered with interpretation of the EBV profile. In contrast, Immulite® performed similarly to the 2 other assays for detection of VCA IgM.
Asunto(s)
Anticuerpos Antivirales/sangre , Antígenos Virales/sangre , Infecciones por Virus de Epstein-Barr/diagnóstico , Herpesvirus Humano 4/inmunología , Inmunoensayo/métodos , Infecciones por Virus de Epstein-Barr/virología , Herpesvirus Humano 4/aislamiento & purificación , Humanos , Inmunoglobulina G/sangre , Inmunoglobulina M/sangre , Estudios Retrospectivos , Sensibilidad y Especificidad , VirologíaRESUMEN
BACKGROUND: Quantitation of hepatitis C virus (HCV) RNA has become an essential tool for monitoring antiviral therapies in chronically infected patients. Different quantitative HCV RNA assays have been reported, mainly using techniques based on signal amplification with branched DNA (bDNA) technology or target sequence amplification by reverse-transcription PCR method (RT-PCR). OBJECTIVES AND STUDY DESIGN: An RT-PCR assay using TaqMan (fluorescence-based real-time PCR) and minor groove binding (MGB) probes was designed for the quantitative determination of HCV RNA in the clinical samples. Calculation of the concentration of HCV RNA was based on an external standard curve in the presence of an internal positive control (IPC). RESULTS: The assay detected 550 international units (IU)/mL with >95% probability of a positive result, with a linear range extending up to 10,000,000 IU/mL. The test exhibited good reproducibility with intra-assay and inter-assay coefficients of variation (CV) of 1.6% and 3.2%, respectively. All the major HCV genotypes were quantified with equivalent efficiency and accuracy. HCV genotypes 5 and 6 have also been amplified but too few samples have been tested. The performance of this new assay for quantitation of HCV viremia was evaluated with 213 anti-HCV positive sera, 120 of which corresponded to 30 patients sampled during the therapy. We used the Amplicor HCV Monitor assay (Roche Diagnostics, France) and the bDNA VERSANT HCV RNA assay (Bayer Diagnostics, France) to analyze 173 and 40 samples, respectively. The assay described here was significantly correlated with both commercial assays (R2 = 0.9535, P < 0.0001 and R2 = 0.8508, P < 0.0001, respectively). CONCLUSION: The present study illustrated the high reproducibility and reliability of our TaqMan HCV assay. Moreover, the monitoring of viral decline with our assay gave the same results as those obtained with the commercial assays indicating that this new technique provides an attractive approach for measuring HCV viral load.