Summary

Transmission | 69

2. Transmission

Bernd Sebastian Kamps Christian Hoffmann

Summary

The fundamental engines that drive the COVID-19 pandemic are now well established (Lee EC 2020, Madewell 2020). A summary (Meyerowitz 2020): 1. Respiratory transmission is the dominant mode of transmission. 2. Vertical transmission occurs rarely; transplacental transmission has been documented. 3. Direct contact and transmission through fomites (inanimate objects) are presumed but are likely only an unusual mode of transmission. 4. Although live virus has been isolated from saliva and stool and viral RNA has been isolated from semen and blood donations, there are no reported cases of SARS-CoV-2 transmission via fecal–oral, sexual, or bloodborne routes. To date, there is one cluster of possible fecal–respiratory transmission. 5. Cats and ferrets can be infected and transmit to each other, but there are no reported cases to date of transmission to humans; minks transmit to each other and to humans.

For everyday life, the following five rules of thumb are helpful: 1. Avoid crowded places (more than 5-10 people). The more people are grouped together, the higher the probability that a superspreader (see page 84) is present who emits infectious particles tens or hundreds times more than a ‘normally’ contagious individual. 2. Avoid in particular crowded and closed spaces (the worst: airconditioned closed places where ‘old air’ is being moved around). In a room where a SARS-CoV-2 infected individual is coughing frequently, viable virus can be isolated from samples collected 2 to 4,8 meters away. 3. Avoid in all circumstances crowded, closed and noisy spaces where people must shout to communicate. Noise from machines or music in a closed environment creates the perfect setting for a superspreader event. 4. Outside crowded, closed or noisy spaces, keep a distance of 2 meters to other people. 5. Always wear a fask mask in public spaces.