Is masturbation a risk for STDs?

Sexually transmitted diseases are transmitted through unprotected sex in which takes place a significant exchange of fluids and secretions (semen, vaginal secretions, blood, and only in rare cases, even saliva), and in most cases STDs aren’t transmitted by masturbation because in this type of sexual practice the contact with fluids is very limited. But the Papilloma Virus can also be contracted by masturbation. In fact this is the only case in which the condom is not a secure method to prevent a sexually transmitted disease.