RESUMEN
A multicentric clinical study was conducted on representative sera from 1,738 European and U.S. subjects for the evaluation of new anti-hepatitis A virus enzyme immunoassays from Bio-Rad Laboratories. Comparison with reference DiaSorin S.p.A. tests confirmed the good performance of Bio-Rad assays (99.85% and 99.47% overall agreement in detecting total antibodies and IgM, respectively).
Asunto(s)
Técnicas de Laboratorio Clínico/métodos , Anticuerpos de Hepatitis A/sangre , Virus de la Hepatitis A/inmunología , Hepatitis A/diagnóstico , Inmunoglobulina M/sangre , Humanos , Técnicas para Inmunoenzimas/métodosRESUMEN
PURPOSE OF THE STUDY: Very few is known on genotype II hepatitis A virus (HAV) since it is rarely isolated. From 2002 to 2007, the French observatory of HAV identified six sub-genotype IIA strains of which one from a patient having travelled to West Africa. To investigate the possible African origin of sub-genotype IIA, we determined its prevalence among French travellers in 2008 and characterised its genetic variability. PATIENTS AND METHODS: The 2008 mandatory notification records were screened for travel to Africa. Viral genotype was determined on the nucleotide sequencing of the VP1/2A junction region. The P1 region coding for capsid proteins was used to compare the genetic diversity of IIA isolates to those of other genotypes. RESULTS: In 2008, five out of 54 patients returning from West Africa were infected by IIA strains and an additional "autochthonous" case was identified. Two more African cases were identified in 2009. A total of 14 IIA isolates (eight African and six "autochthonous") were analysed. Nucleotide and amino-acid variability of IIA sequences was lower than that of the other genotypes. Phylogenetic analysis revealed the clustering of two "autochthonous" cases with African isolates whereas the other ones belonged to a different lineage. CONCLUSION: Most IIA strains isolated in France are imported by travellers returning from West Africa. However, the unexplained contamination mode of some "autochthonous" cases suggests another geographical origin to discover or a French reservoir to explore.
Asunto(s)
Virus de la Hepatitis A/genética , Hepatitis A/virología , ARN Viral/genética , Adolescente , Adulto , África Occidental , Secuencia de Aminoácidos , Niño , Femenino , Francia , Variación Genética , Genotipo , Virus de la Hepatitis A/clasificación , Humanos , Masculino , Persona de Mediana Edad , Datos de Secuencia Molecular , Filogenia , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Viaje , Proteínas Estructurales Virales/genética , Adulto JovenRESUMEN
A new, dry method for converting photographically recorded amplitude holograms to high diffraction efficiency phase holograms is described. The dry method involves the application of elemental bromine or chlorine. The bromine vapor bleaching of transmission holograms produced efficiencies of 70.8% in dry film and 75.5% in water swelled layers. Index modulations of 0.033 have been observed. Reflection hologram efficiencies of 73% were obtained. The stability of the bromine vapor bleached holograms to printout is superior to all previous methods.