TY - JOUR T1 - SARS-CoV-2 surveillance in Norway rats (<em>Rattus norvegicus</em>) from Antwerp sewer system, Belgium JF - bioRxiv DO - 10.1101/2021.03.06.433708 SP - 2021.03.06.433708 AU - Valeria Carolina Colombo AU - Vincent Sluydts AU - Joachim Mariën AU - Bram Vanden Broecke AU - Natalie Van Houtte AU - Wannes Leirs AU - Lotte Jacobs AU - Arne Iserbyt AU - Marine Hubert AU - Leo Heyndrickx AU - Hanne Goris AU - Peter Delputte AU - Naomi De Roeck AU - Joris Elst AU - Robbert Boudewijns AU - Kevin K. Ariën AU - Herwig Leirs AU - Sophie Gryseels Y1 - 2021/01/01 UR - http://biorxiv.org/content/early/2021/03/06/2021.03.06.433708.abstract N2 - Background SARS-CoV-2 human-to-animal transmission can lead to the establishment of novel reservoirs and the evolution of new variants with the potential to start new outbreaks in humans.Aim We tested Norway rats inhabiting the sewer system of Antwerp, Belgium, for the presence of SARS-CoV-2 following a local COVID-19 epidemic peak. In addition, we discuss the use and interpretation of SARS-CoV-2 serological tests on non-human samples.Methods Between November and December 2020, Norway rat oral swabs, feces and tissues from the sewer system of Antwerp were collected to be tested by RT-qPCR for the presence of SARS-CoV-2. Serum samples were screened for the presence of anti-SARS-CoV-2 IgG antibodies using a Luminex microsphere immunoassay (MIA). Samples considered positive were then checked for neutralizing antibodies using a conventional viral neutralization test (cVNT).Results The serum of 35 rats was tested by MIA showing 3 potentially positive sera that were later shown to be negative by cVNT. All tissue samples of 39 rats analyzed tested negative for SARS-CoV-2 RNA.Conclusion This is the first study that evaluates SARS-CoV-2 infection in urban rats. We can conclude that the sample of 39 rats had never been infected with SARS-CoV-2. We show that diagnostic serology tests can give misleading results when applied on non-human samples. SARS-CoV-2 monitoring activities should continue due to the emergence of new variants prone to infect Muridae rodents.Competing Interest StatementThe authors have declared no competing interest. ER -