1 / 12

Full characterization of HAV RNA window period positive blood donations in Germany

Full characterization of HAV RNA window period positive blood donations in Germany. SoGAT XVIII Bethesda. Hepatitis A Virus. Picornavirus Non-enveloped First isolated in 1979 Natural host: human Stable: heat and acid-resistant Inactivated by high temperature, formalin, chlorine

clyde
Download Presentation

Full characterization of HAV RNA window period positive blood donations in Germany

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Full characterization of HAV RNA window period positive blood donations in Germany SoGAT XVIII Bethesda

  2. Hepatitis A Virus • Picornavirus • Non-enveloped • First isolated in 1979 • Natural host: human • Stable: heat and acid-resistant • Inactivated by high temperature, formalin, chlorine • Transmission: fecal-oral • Replication: liver (hepatocytes) • Peak viremia 10-12 days after infection • Self-limited illness: asymptomatic or acute fulminant hepatitis

  3. HAV Pathogenesis • Incubation period of 15-50 days • Prodromal illness is nonspecific • Age-related severity: • Children <6 years: 70% of infections are asymptomatic • Older children and adults >70% of cases result in acute hepatitis with jaundice

  4. HAV Recent Developments in Germany • RT-PCR based tests for the presence of HAV RNA were • introduced in Germany in 2000. • Systems: • In house • Artus based technology transfer • Technology: • Real time RT PCR • LightCyler/ABI Prism

  5. HAV Kit Adaptation HAV positive blood donation (in house test) • Artus/Roche negative • Inhouse 4+/4- • Enterovirus etc. negative • Contamination/unspecific? • What to do? • Clinical positive (2 weeks later)

  6. HAV Kit Adaptation Tests • 7 real time PCRs spanning the HAV genome • 6 negative • 1 positive (ct 28) • Long range PCR • Sequencing • Culture

  7. HAV Kit Adaptation • Real time pos. HAV Genotype III • Full length pos. HAV Genotype IIIA • Cell culture pos. And the Kit ??

  8. HAV Kit Adaptation • New Kit (with CE mark) • Alignment (conserved region) • Sensitivity • Specificity • Robustness • Positive Controls • Precision

  9. HAV Kit Adaptation • Results: New Kit (with CE mark) • Alignment • VP4 highest homology • Sensitivity (with new primer and probes) • 183 IU/ml (WHO Int. Std/Qiagen Extr.) • Specificity • all available strains (in vitro) • 100% (HAV Ab neg.) • weak crossreactivity with Enterovirus 71 • Precision • intra-assay 28 % • inter-assay 31 % • total 32 %

  10. HAV Kit Adaptation • Results: New Kit (with CE mark) • End of 2003 Kit release • Detection of: • 1 food associated HAV-RNA positive blood donation • 4 travel related HAV-RNA positive blood donation • only 1 would have been detected with the old system • All Genotype I

  11. HAV Kit • Availabiliy • As IVD • Worldwide • 2. For blood screening • LC-PCR based Systems (via Roche starting in Juli/August 2005) • ABI Prism based Systems (via Abbott) • Country specific restrictions may apply

  12. HAV Kit • Acknowledgments • The German Red Cross Blood Transfusion Service of Baden Württemberg-Hessen, PCR Lab in Frankfurt • The German Red Cross Blood Transfusion Center West in Hagen • Blood Center of the German Red Cross NSTOB, Institute Springe • Department of Virology, University of Bremen

More Related