Cofty is right, a mask is really limited in how it can protect you, it actually takes training, practice and dedication to make it work properly. These medical professionals take the quarantine and protection to a different level that most ordinary folk can never attain to, certainly not by just wearing a mask. When working with highly infectious disease outbreaks there is more education needed even for the experienced doctors in these regards.
It would seem silly that any person could be afforded the same protection as a trained medical professional by just wearing a mask, that protection comes with a host of other stringent conditions and procedures