The new type of respiratory tract disorder COVID-19 is based on an infection with the new type of coronavirus (SARS-CoV-2). Knowledge about the exact transmission methods of this coronavirus is still limited. However, the transmission methods of other closely related coronaviruses are well known. Different types of coronavirus typically trigger conventional colds in humans. Moreover, other coronaviruses, such as the SARS and MERS coronaviruses, have occurred in the past and have led to severe respiratory tract disorders. The main target organs of coronaviruses in humans are the respiratory tract organs.

The most important transmission pathway of SARS-CoV-2 is considered to be a so-called “droplet infection”, in which the viruses are released into the air by infected people via droplets - for example, when sneezing or coughing - and then inhaled. In certain situations, aerosol transmission (droplet nuclei, smaller than five micrometres) - for example, when speaking - also seems possible. Furthermore, transmission via contact or smear infections cannot be ruled out. In those cases, pathogens located on the hands enter the mucus membranes of the nose or eyes, where they may lead to an infection.

The distribution of virus docking sites (receptors) in the human body also suggests that transmission mainly takes place via the respiratory tract. SARS-CoV-2 requires the two proteins ACE2 and TMPRSS2 to enter the host cells. In humans, different types of cells produce these proteins. However, according to new findings certain cells in the mucous membrane of the nose produce particularly large quantities of these proteins. It is, therefore, assumed that SARS-CoV-2 primarily uses the nose as a port of entry:

You will find more information on these transmission methods (in German) from the Robert- Koch-Institute (RKI) at

(here: 1. Übertragungswege)

The RKI is in close contact with the World Health Organisation (WHO) and monitors all up-to-date news about the event.

In special cases, orders are issued by the local public health offices, which can be contacted for further information: