Welcome! Thanks for your post.
You can review basic HPV transmission information on our site at http://www.ashastd.org/learn/learn_hpv_facts.cfm
. Genital HPV is transmitted through skin to skin contact. This includes any genital to genital contact, as well as vaginal and anal sex (even without penetration).
There are well over 100 types of HPV, the vast majority of which are not associated with anogenital skin or sexual transmission. This would include, for example, the HPV types that might cause common warts found on the hands and feet.
So, genital HPV is regarded as a sexually transmitted infection. Having said that, there do seem to be unexplained cases of nonsexual transmission, although this is not regarded as common and experts aren't too sure just how it might occur. The focus of genital HPV transmission should remain directly on the genital/anal contact described above, but it's just difficult to rule anything out.
Hope this helps.
All the best,