Seroepidemiological study on the spread of SARS-CoV-2 in Germany:

The SARS-CoV-2 coronavirus has spread rapidly across Germany. Infections are likely to be under-recorded in the notification data from local health authorities on laboratory-confirmed cases since SARS-CoV-2 infections can proceed with few symptoms and then often remain undetected. Seroepidemiological studies allow the estimation of the proportion in the population that has been infected with SARS-CoV-2 (seroprevalence) as well as the extent of undetected infections. The ‘CORONA-MONITORING bundesweit’ study (RKI-SOEP study) collects biospecimens and interview data in a nationwide population sample drawn from the German Socio-Economic Panel (SOEP). Participants are sent materials to self-collect a dry blood sample of capillary blood from their finger and a swab sample from their mouth and nose, as well as a questionnaire. The samples returned are tested for SARS-CoV-2 IgG antibodies and SARS-CoV-2 RNA to identify past or present infections. The methods applied enable the identification of SARS-CoV-2 infections, including those that previously went undetected. In addition, by linking the data collected with available SOEP data, the study has the potential to investigate social and health-related differences in infection status. Thus, the study contributes to an improved understanding of the extent of the epidemic in Germany, as well as identification of target groups for infection protection

Low Pathogenic Avian Influenza Isolates from Wild Birds Replicate and Transmit via Contact in Ferrets without Prior Adaptation

Direct transmission of avian influenza viruses to mammals has become an increasingly investigated topic during the past decade; however, isolates that have been primarily investigated are typically ones originating from human or poultry outbreaks. Currently there is minimal comparative information on the behavior of the innumerable viruses that exist in the natural wild bird host. We have previously demonstrated the capacity of numerous North American avian influenza viruses isolated from wild birds to infect and induce lesions in the respiratory tract of mice. In this study, two isolates from shorebirds that were previously examined in mice (H1N9 and H6N1 subtypes) are further examined through experimental inoculations in the ferret with analysis of viral shedding, histopathology, and antigen localization via immunohistochemistry to elucidate pathogenicity and transmission of these viruses. Using sequence analysis and glycan binding analysis, we show that these avian viruses have the typical avian influenza binding pattern, with affinity for cell glycoproteins/glycolipids having terminal sialic acid (SA) residues with α 2,3 linkage [Neu5Ac(α2,3)Gal]. Despite the lack of α2,6 linked SA binding, these AIVs productively infected both the upper and lower respiratory tract of ferrets, resulting in nasal viral shedding and pulmonary lesions with minimal morbidity. Moreover, we show that one of the viruses is able to transmit to ferrets via direct contact, despite its binding affinity for α 2,3 linked SA residues. These results demonstrate that avian influenza viruses, which are endemic in aquatic birds, can potentially infect humans and other mammals without adaptation. Finally this work highlights the need for additional study of the wild bird subset of influenza viruses in regard to surveillance, transmission, and potential for reassortment, as they have zoonotic potential

Avian Influenza Viruses Infect Primary Human Bronchial Epithelial Cells Unconstrained by Sialic Acid α2,3 Residues

Avian influenza viruses (AIV) are an important emerging threat to public health. It is thought that sialic acid (sia) receptors are barriers in cross-species transmission where the binding preferences of AIV and human influenza viruses are sias α2,3 versus α2,6, respectively. In this study, we show that a normal fully differentiated, primary human bronchial epithelial cell model is readily infected by low pathogenic H5N1, H5N2 and H5N3 AIV, which primarily bind to sia α2,3 moieties, and replicate in these cells independent of specific sias on the cell surface. NHBE cells treated with neuraminidase prior to infection are infected by AIV despite removal of sia α2,3 moieties. Following AIV infection, higher levels of IP-10 and RANTES are secreted compared to human influenza virus infection, indicating differential chemokine expression patterns, a feature that may contribute to differences in disease pathogenesis between avian and human influenza virus infections in humans

Seroepidemiologische Studie zur bundesweiten Verbreitung von SARS-CoV-2 in Deutschland: Studienprotokoll von CORONA-MONITORING bundesweit (RKI-SOEP-Studie)

Das Coronavirus SARS-CoV-2 hat sich in kurzer Zeit bundesweit ausgebreitet. In den Meldedaten der Gesundheitsämter zu laborbestätigten Infektionsfällen ist von einer Untererfassung des Infektionsgeschehens auszugehen, da Infektionen häufig unentdeckt bleiben, zum Beispiel weil sie symptomarm verlaufen. In seroepidemiologischen Studien kann der Bevölkerungsanteil mit durchgemachter SARS-CoV-2-Infektion (Seroprävalenz) wie auch der Umfang unentdeckter Infektionen abgeschätzt werden. In der Studie CORONA-MONITORING bundesweit (RKI-SOEP-Studie) werden Bioproben und Befragungsdaten in einer deutschlandweiten Bevölkerungsstichprobe des Sozio-oekonomischen Panels (SOEP) erhoben. Den Teilnehmenden werden Materialien zur selbstständigen Gewinnung einer Trockenblutprobe aus Kapillarblut des Fingers und einer Abstrichprobe aus Mund und Nase sowie ein Fragebogen postalisch zugesendet. Die zurückgesendeten Proben werden auf SARS-CoV-2-IgG-Antikörper und SARS-CoV-2-RNA zur Identifikation einer durchgemachten oder aktuellen Infektion untersucht. Die eingesetzten Methoden ermöglichen es, auch solche SARS-CoV-2-Infektionen zu erkennen, die bislang unentdeckt blieben. Durch die Verknüpfung mit bereits vorhandenen SOEP-Daten hat die Studie das Potenzial, auch soziale und gesundheitsbezogene Unterschiede im Infektionsstatus zu untersuchen. So kann die Studie zu einem verbesserten Verständnis des Ausmaßes der Epidemie in Deutschland wie auch zur Identifikation von Zielgruppen für den Infektionsschutz beitragen