  Since the beginning of March 2020, the cumulative numbers of cases of
infection with the novel coronavirus SARS-CoV-2 in Germany have been reported
on a daily basis. The reports originate from national laws, according to which
positive test findings must be submitted to the Federal Health Authorities, the
Robert Koch Institute, via the local health authorities. Since an enormous
number of unreported cases can be expected, the question of how widespread the
disease has been in the population cannot be answered based on these
administrative reports. Using mathematical modeling, however, estimates can be
made. These estimates indicate that the small numbers of diagnostic tests
carried out at the beginning of the outbreak overlooked considerable parts of
the infection. In order to cover the initial phase of future waves of the
disease, wide-spread and comprehensive tests are recommended.
