@article{KruegerLeskienSchulleretal.2021,
  author    = {Kr{\"u}ger, S{\"o}ren and Leskien, Miriam and Schuller, Patricia and Prifert, Christiane and Weißbrich, Benedikt and Vogel, Ulrich and Krone, Manuel},
  title     = {Performance and feasibility of universal PCR admission screening for SARS-CoV-2 in a German tertiary care hospital},
  series = {Journal of Medical Virology},
  volume    = {93},
  journal   = {Journal of Medical Virology},
  number    = {5},
  doi       = {10.1002/jmv.26770},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-238971},
  pages     = {2890 -- 2898},
  year      = {2021},
  abstract  = {Anamnestic screening of symptoms and contact history is applied to identify coronavirus disease 2019 (COVID-19) patients on admission. However, asymptomatic and presymptomatic patients remain undetected although the viral load may be high. In this retrospective cohort study, all hospitalized patients who received polymerase chain reaction (PCR) admission testing from March 26th until May 24th, 2020 were included. Data on COVID-19-specific symptoms and contact history to COVID-19 cases were retrospectively extracted from patient files and from contact tracing notes. The compliance to the universal testing protocol was high with 90\%. Out of 6940 tested patients, 27 new severe acute respiratory syndrome coronavirus-2 infections (0.4\%) were detected. Seven of those COVID-19 cases (26\% of all new cases) were asymptomatic and had no positive contact history, but were identified through a positive PCR test. The number needed to identify an asymptomatic patient was 425 in the first wave of the epidemic, 1218 in the low incidence phase. The specificity of the method was above 99.9\%. Universal PCR testing was highly accepted by staff as demonstrated by high compliance. The costs to detect one asymptomatic case in future studies need to be traded off against the costs and damage caused by potential outbreaks of COVID-19.},
  language  = {en}
}
@article{EmmerichMurawskiEhmenetal.2021,
  author    = {Emmerich, Petra and Murawski, Carolin and Ehmen, Christa and von Possel, Ronald and Pekarek, Neele and Oestereich, Lisa and Duraffour, Sophie and Pahlmann, Meike and Struck, Nicole and Eibach, Daniel and Krumkamp, Ralf and Amuasi, John and Maiga-Ascofar{\´e}, Oumou and Rakotozandrindrainy, Raphael and Asogun, Danny and Ighodalo, Yemisi and Kann, Simone and May, J{\"u}rgen and Tannich, Egbert and Deschermeier, Christina},
  title     = {Limited specificity of commercially available SARS-CoV-2 IgG ELISAs in serum samples of African origin},
  series = {Tropical Medicine \& International Health},
  volume    = {26},
  journal   = {Tropical Medicine \& International Health},
  number    = {6},
  doi       = {10.1111/tmi.13569},
  url       = {http://nbn-resolving.de/urn:nbn:de:bvb:20-opus-239899},
  pages     = {621 -- 631},
  year      = {2021},
  abstract  = {Objectives Specific serological tests are mandatory for reliable SARS-CoV-2 diagnostics and seroprevalence studies. Here, we assess the specificities of four commercially available SARS-CoV-2 IgG ELISAs in serum/plasma panels originating from Africa, South America, and Europe. Methods 882 serum/plasma samples collected from symptom-free donors before the COVID-19 pandemic in three African countries (Ghana, Madagascar, Nigeria), Colombia, and Germany were analysed with three nucleocapsid-based ELISAs (Euroimmun Anti-SARS-CoV-2-NCP IgG, EDI™ Novel Coronavirus COVID-19 IgG, Mikrogen recomWell SARS-CoV-2 IgG), one spike/S1-based ELISA (Euroimmun Anti-SARS-CoV-2 IgG), and in-house common cold CoV ELISAs. Results High specificity was confirmed for all SARS-CoV-2 IgG ELISAs for Madagascan (93.4-99.4\%), Colombian (97.8-100.0\%), and German (95.9-100.0\%) samples. In contrast, specificity was much lower for the Ghanaian and Nigerian serum panels (Ghana: NCP-based assays 77.7-89.7\%, spike/S1-based assay 94.3\%; Nigeria: NCP-based assays 39.3-82.7\%, spike/S1-based assay 90.7\%). 15 of 600 African sera were concordantly classified as positive in both the NCP-based and the spike/S1-based Euroimmun ELISA, but did not inhibit spike/ACE2 binding in a surrogate virus neutralisation test. IgG antibodies elicited by previous infections with common cold CoVs were found in all sample panels, including those from Madagascar, Colombia, and Germany and thus do not inevitably hamper assay specificity. Nevertheless, high levels of IgG antibodies interacting with OC43 NCP were found in all 15 SARS-CoV-2 NCP/spike/S1 ELISA positive sera. Conclusions Depending on the chosen antigen and assay protocol, SARS-CoV-2 IgG ELISA specificity may be significantly reduced in certain populations probably due to interference of immune responses to endemic pathogens like other viruses or parasites.},
  language  = {en}
}