Infective agents can be transmitted during surgical procedures in operating theatres and other medical settings in several ways. One of the important sources are the noses and mouths of the surgical team. When breathing, speaking, coughing or sneezing, a person releases smaller or larger amounts of droplets of secretions from the mucous membranes in the mouth and nose. Those droplets quickly evaporate and leave nuclei suspended in the air. Nuclei can subsequently spread through the air to a susceptible site such as an open operating wound or sterile equipment, or can be inhaled if dimensions