Nurses and health practitioners will tell you to wear a condom to prevent contracting an STD/STI, and will supplement this with "diseases and infections can be transmitted through bodily fluids which come in contact with cuts and wounds" etc.
But how does the virus enter the body? which specific parts of the body/organs come into play? Is there a specific part of the penis/vagina where the skin allows the virus to permeate or does it go through the urethra Where does the virus originate from and how does it reach its end destination?