2 results
Transmission of SARS-CoV-2 among children and staff in German daycare centres
- Julika Loss, Juliane Wurm, Gianni Varnaccia, Anja Schienkiewitz, Helena Iwanowski, Anne-Kathrin Mareike Loer, Jennifer Allen, Barbara Wess, Angelika Schaffrath Rosario, Stefan Damerow, Tim Kuttig, Hanna Perlitz, Anselm Hornbacher, Bianca Finkel, Carolin Krause, Jan Wormsbächer, Anna Sandoni, Ulrike Kubisch, Kiara Eggers, Andreas Nitsche, Aleksandar Radonic, Kathrin Trappe, Oliver Drechsel, Kathleen Klaper, Andrea Franke, Antje Hüther, Udo Buchholz, Walter Haas, Lothar H. Wieler, Susanne Jordan
-
- Journal:
- Epidemiology & Infection / Volume 150 / 2022
- Published online by Cambridge University Press:
- 08 July 2022, e141
-
- Article
-
- You have access Access
- Open access
- HTML
- Export citation
-
In daycare centres, the close contact of children with other children and employees favours the transmission of infections. The majority of children <6 years attend daycare programmes in Germany, but the role of daycare centres in the SARS-CoV-2 pandemic is unclear. We investigated the transmission risk in daycare centres and the spread of SARS-CoV-2 to associated households. 30 daycare groups with at least one recent laboratory-confirmed SARS-CoV-2 case were enrolled in the study (10/2020–06/2021). Close contact persons within daycare and households were examined over a 12-day period (repeated SARS-CoV-2 PCR tests, genetic sequencing of viruses, symptom diary). Households were interviewed to gain comprehensive information on each outbreak. We determined primary cases for all daycare groups. The number of secondary cases varied considerably between daycare groups. The pooled secondary attack rate (SAR) across all 30 daycare centres was 9.6%. The SAR tended to be higher when the Alpha variant was detected (15.9% vs. 5.1% with evidence of wild type). The household SAR was 53.3%. Exposed daycare children were less likely to get infected with SARS-CoV-2 than employees (7.7% vs. 15.5%). Containment measures in daycare programmes are critical to reduce SARS-CoV-2 transmission, especially to avoid spread to associated households.
15 - RNA interference in postimplantation mouse embryos
-
- By Frank Buchholz, Max Plank Institute of Molecular Cell Biology and Genetics, Federico Calegari, Max Plank Institute of Molecular Cell Biology and Genetics, Ralf Kittler, Max Plank Institute of Molecular Cell Biology and Genetics, Wieland B. Huttner, Max Plank Institute of Molecular Cell Biology and Genetics
- Edited by Krishnarao Appasani, GeneExpression Systems, Inc., Massachusetts
- Foreword by Andrew Fire, Stanford University, California, Marshall Nirenberg
-
- Book:
- RNA Interference Technology
- Published online:
- 31 July 2009
- Print publication:
- 17 January 2005, pp 207-219
-
- Chapter
- Export citation
-
Summary
Introduction
Sequencing of whole genomes has provided new perspectives into the blueprints of diverse organisms, including the genome of the mouse (Waterston et al., 2002). Although the complete sequence is now available, the estimation of total gene number encoded by the mouse genome is ranging approximately from 25,000 to 50,000 (Okazaki et al., 2002). This uncertainty about the functional units within the genome highlights the importance of a detailed analysis of the encoded genes.
A significant step toward a better understanding of the genome has been the development of large-scale gene expression analysis tools utilizing DNA microarrays (Bono et al., 2003). This technology allows the generation of gene expression profiles that can give important clues for the interpretation of biological processes. However, the obtained data do not directly address the function of individual genes. Rather, they present a snapshot of global gene expression changes. While this is a very useful parameter for understanding the genome, it is not very useful for studying detailed phenotypic changes after gene ablation.
About 15 years ago gene function analysis became available in the mouse through the development of gene knock-out technology (Capecchi, 1989). In this approach genes are targeted in embryonic stem (ES) cells through homologous recombination. The manipulated ES cells are subsequently injected into blastocysts, and chimeric offspring are checked for germline transmission. Successful germline transmission allows the production of animals deficient in the gene of interest. Careful phenotypic analyses of these animals can then disclose the function(s) of the knocked-out gene.