Browsing by Author "Baylis, S.A."
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- Harmonization of nucleic acid testing for Zika virus: development of the 1st World Health Organization International StandardPublication . Baylis, S.A.; Hanschmann, K-M.O.; Schnierle, D.S.; Trösemeier, J-H.; Blümel, J.; Zika Virus Collaborative Study GroupBACKGROUND: With the ongoing public health emergency due to Zika virus (ZIKV), nucleic acid testing (NAT) is essential for clinical diagnosis and screening of blood donors. However, NAT for ZIKV has not been standardized, and this study was performed to establish a World Health Organization (WHO) International Standard (IS) for ZIKV RNA; WHO ISs have been used to improve detection and quantification of blood-borne viruses. STUDY DESIGN AND METHODS: The candidate IS (cIS), code number 11468/16, was prepared by heat inactivation and lyophilization of a ZIKV strain isolated from a patient in French Polynesia in 2013. The cIS was evaluated together with other reference materials, including both Asian and African ZIKV lineages as well as a panel of clinical samples and in vitro-transcribed RNAs. The samples for evaluation were distributed to 24 laboratories from 11 countries. The assays used consisted of a mixture of in-house developed and commercial assays (available or in development). RESULTS: The potencies of the standards were determined by quantitative and qualitative assays. In total, 37 sets of data were analyzed: 19 from quantitative assays and 18 from qualitative assays. Data demonstrated wide variations in reported potencies of the cIS and the other study samples. CONCLUSIONS: Assay variability was substantially reduced when ZIKV RNA concentrations from the biological reference materials and clinical samples were expressed relative to the cIS. Thus, the WHO has established 11468/16 as the 1st IS for ZIKV RNA, with a unitage of 50,000,000 IU/mL.
- Standardising surveillance of hepatitis E virus infection in the EU/EEA: a review of national practices and suggestions for the way forwardPublication . Adlhoch, C.; Mand'áková, Z.; Ethelberg, S.; Epštein, J.; Rimhanen-Finne, R.; Figoni, J.; Baylis, S.A.; Faber, M.; Mellou, K.; Murphy, N.; O'Gorman, J.; Tosti, M.E.; Ciccaglione, A.R.; Hofhuis, A.; Zaaijer, H.; Lange, H.; de Sousa, R.; Avellón, A.; Sundqvist, L.; Said, B.; Ijaz, S.Background: Hepatitis E virus (HEV) infection is not notifiable at EU/EEA level, therefore surveillance relies on national policies only. Between 2005 and 2015, more than 20,000 cases were reported in EU/EEA countries. HEV testing is established in 26 countries and 19 countries sequence HEV viruses. Objective and study design: WHO's European Action plan for viral hepatitis recommends harmonised surveillance objectives and case definitions. ECDC's HEV expert group developed minimal and optimal criteria for national hepatitis E surveillance to support EU/EEA countries in enhancing their capacity and to harmonise methods. Results: The experts agreed that the primary objectives of national surveillance for HEV infections should focus on the basic epidemiology of the disease: to monitor the incidence of acute cases and chronic infections. The secondary objectives should be to describe viral phylotypes or subtypes and to identify potential clusters/outbreaks and possible routes of transmission. Seventeen of 20 countries with existing surveillance systems collect the minimal data set required to describe the epidemiology of acute cases. Eleven countries test for chronic infections. Twelve countries collect data to identify potential clusters/outbreaks and information on possible routes of transmission. Discussion: Overall, the majority of EU/EEA countries collect the suggested data and meet the outlined requirements to confirm an acute case.