Status: nosocomial transmission and prevention of SARS-CoV-2 in a Danish context.

The unexpected pandemic with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has challenged the healthcare sector as regards preventing and controlling the virus from spreading between patients and hospital personnel. The massive spread of the pandemic has led state authorities to introduce restrictions on society and public behavior unprecedented in modern times. First, we describe the Danish effort regarding standard precautions, personal protective equipment, and disinfection in the healthcare setting with Denmark as an example. As regards, the number of coronavirus disease 2019 (COVID-19)-related hospital submissions, deaths, and infected healthcare workers in Denmark is not the hardest hit country compared with others. This cannot be explained by the hardness of the restrictions alone. Several aspects concerning the person-to-person spread of SARS-CoV-2 are not fully understood and require more experimental studies. The dogma is that virus transmission happens through either respiratory droplets or contact routes. However, it is likely not the whole truth, as we describe scenarios where droplets and/or direct contact cannot alone explain how all patients were infected. Aspects of the physiology of airborne transmission are considered, as several parameters are in play beyond particle size and respiratory rate. These are ozone concentration, ambient temperature, and humidity. In a hospital environment, these factors are not necessarily all controllable, making infection prevention and control a challenge.