BACKGROUND At the beginning of the COVID-19 pandemic, the German Robert Koch Institute (RKI) published several guidelines addressing the medical health services helping to detect SARS CoV‑2 . Needing an available and specific test strategy regarding SARS-CoV‑2, our own test strategy strictly followed these testing criteria . MATERIALS AND
METHODS Using a retrospective analysis, we verified if such a test strategy was an effective tool in the context of infection prevention control and as reliable SARS-CoV‑2 detection . Therefore, we analysed our own test results of suspected SARS-CoV‑2 cases between 26 February and 6 April 2020 . Additionally, we used a geovisualisation tool to visualise test frequencies and positive test results within different districts of Mannheim based on people's addresses .
RESULTS There were on average 7% positive test results of SARS-CoV‑2 within a population with typical symptoms of COVID-19 (n = 2808). There was no positive test result within an asymptomatic population (n = 448). However, one positive test result turned out to be a nosocomial infection . Finally, geovisualisation highlighted a shift of test frequencies and local positive rates for SARS-CoV‑2 from one district of Mannheim to another .
DISCUSSION In conclusion, our test strategy strictly based on testing criteria suggested by the Robert Koch Institute resulted in a steady rate of positive tests and allowed us to increase test capacity without causing numbers of nosocomial infections of COVID-19 . Geovisualisation tools can offer support in analysing an ongoing spread of transmissible diseases . In the future, they could be used as helpful tools for infection prevention control, for example in the context of vaccination programs.