Markus - I am not well versed enough outside of the HPV arena to comment on bacterial and other viral etiologies. Right now other than HPV, there isn't any evidence that the faster entry of some bacterial or other viral agent would produce a cellular cascade of events to malignancy. Does that mean it couldn't happen? No. After all, it was decades of ridicule before the guys that tied a bacterium to stomach ulcers were given credit for it, as everyone still thought it was a stress related condition. Other viruses (some) need an mechanism of entry, as they do not transfer through epithelial contact as with HPV and need some entry point, and I suppose that a non healing irritation combined with the appropriate cause - that used that spot as a route of entry, could do something. There are 9 viruses known to cause cancers, but HPV is the only one tied to oral at this time. In an allied area there is Epstein-Barr virus which cases naso-pharyngeal cancers (along with nickel exposure as anther primary etiology in factory workers that come into heavy contact with it) But at the end of the day, speaking of what we know today, it just ain't so. What we know ten years from now is anyone's guess, so I try to be careful not to talk in absolutes about things. Just last year we discovered a new virus that causes a previously unknown skin cancer, rare, but goes to show you that we sure don't know it all.