One of my customers pointed out this very effective new Patent Pending anti spit mask, designed for those troublesome prisoners who will insist on spitting and biting fellow prisoners, not to mention prison staff and Court Officials.  Named 'Innoshield' by Bob Barker this is not designed to be an anti infection mask but I suppose it might work.  The only slight problem is that when you wear it you tend to look like a man about to rob a bank, which, I guess, is quite appropriate!

Here is the Bob Barker video showing officers how to apply

http://www.youtube.com/embed/EmUg6OnVTVY?enablejsapi=1&version=3&playerapiid=youtubevideo