A research group led by Associate Professor Kenichi Higashi of the Kinki University School of Medicine calculated the risk of the new coronavirus by infection route in the medical field.We have constructed a model that estimates risks by droplet, contact, and airborne infection, and also evaluates the effects of taking infection prevention measures such as face shields.
According to Kinki University, the research group assumed a medical site that treats patients in a close proximity of about 0.6 meters, built a model to estimate the risk for each infection route, and simulated the risk of medical staff.
As a result, the highest risk was when the patient's droplets adhered directly to the mucous membrane of the face of the healthcare worker, reaching 60-86%.Then 9-32% of the risk of contact transmission from contaminated surfaces.It was also found that this case was at greater risk with longer patient contact and less frequent hand washing.It was also found that if the virus concentration in the patient's saliva is very high, the risk of airborne infection from droplets increases by 5 to 27%.
As for the effects of the measures, the risk of infection was reduced by 63 to 64% when the medical staff used the surgical mask, 97 to 98% when wearing the face shield, and 99% or more when both the surgical mask and the face shield were used.It was found that the risk was reduced by more than 99% when the patient wore a surgical mask, and the risk was reduced to less than half when the patient wore a surgical mask and increased the ventilation rate three times as much as usual.
