The coronavirus SARS-CoV-2, which was first detected in 2019, spread worldwide from 2020 onwards, causing mild to fatal illness in people in all countries of the world. The most likely starting point of the pandemic was transmission from animals (initially probably bats) to humans. In the course of the massive pandemic, it eventually spread to other animal species, some of which live in the direct vicinity of humans. Therefore, animal studies on the susceptibility of farm animals and pets were carried out at the Friedrich-Loeffler-Institut at the beginning of the pandemic. These showed that not all animal species are equally susceptible to the virus. An up-to-date overview of the occurrence and susceptibility of different species can be found on the website of the World Organisation for Animal Health (WOAH) (Link to PDF).
Therefore, in July 2020, the obligation to report infections of animals with the novel coronavirus SARS-CoV-2 was introduced in Germany. The National Reference Laboratory for SARS-CoV-2 infections in animals has validated methods for molecular and serological diagnostics of samples collected in connection with SARS-CoV-2. In addition to sensitive and specific in-house methods, commercially available tests are also used for the respective applications. Furthermore, the NRL participates in national and international ring tests, organizes national ring trials, serves as a contact for the veterinary testing laboratories of the countries and conducts research on the occurrence, diagnostics, pathogenesis, therapy, control and immunoprophylaxis of SARS-CoV2 infections in animals.
The detection of SARS-CoV-2 pathogens and post-exposure induced immune reactions requires specific and sensitive analytical methods. The exclusion of cross-reactions with other corona viruses, which are frequently found in animals, plays an essential role. For the development, optimization and validation of molecular and serological detection methods for SARS-CoV-2 diagnostics in animals, existing test systems will be further developed, with particular emphasis on further possible transmission of animal corona viruses to humans. Regarding molecular detection methods, the upgrading of simplex RT-qPCRs for the specific detection of individual coronavirus species to multiplex assays, which allow the simultaneous detection of several viruses, plays a decisive role. An even wider target spectrum of corona viruses from various pets and farm animals is achieved by the development of coronavirus-specific microarrays. This will enable the concurrent detection of nucleic acids of different corona viruses in a single sample with high sensitivity and specificity. The use of cross-species serological detection methods, such as the further development of surrogate neutralization tests, will facilitate the general detection of antibodies. The tests will be optimized so that only antibodies specific for certain corona viruses are detected (exclusion of cross-reactivity and simultaneous host-species independence). Rapid tests based on Lateral Flow Devices (LFDs) can serve as the first, non-specific screening method. To ensure that the test systems described can be successfully and reliably used in practice, their development will be followed by a validation phase using reference materials that originate from a corona virus biobank that is also to be established within this project. In addition to a collection of relevant corona viruses from various sources, this biobank will include a compilation of defined sera with known antibody content.