Analysis of the COVID-19 pandemic in Bavaria: adjusting for misclassification

Guenther, F.; Bender, A.; Höhle, M.; Wildner, M.; Küchenhoff, H.

We present a method for adjusting the observed epidemic curve of daily new COVID-19 onsets for possible misclassification in infection diagnostics. We discuss different assumptions for specificity and sensitivity of the person-specific COVID-19 diagnostics based on PCR-tests, which are the basis for the daily reported case counts. A specificity of less than one implies occurrence of false positive cases, which becomes particularly relevant with an increased number of tests. The recent increase in cases in Bavaria could therefore be smaller than reported. However, an increase in case counts can still be seen from Mid-July until September 2020. The additional consideration of a sensitivity less than one, i.e., the occurrence of false negative tests, results in an epidemic curve in which the daily case counts are increased by a constant factor, but the structure of the curve does not change considerably.