Everything is not 100%. If the place before insertion of the needle is not sanitized, it might get an infection.
Alexandre Hillairet, DAOM.
In California, by law, acupuncturists can only use disposable needles, and proper disinfecting procedures are required. It is just like you go to any MD doctor to receive an injection; same procedure required. The chance of getting infection from acupuncture therapy is just exactly the same as when you receive an injection from MD's office - extremely low.
No, the needles are strictly sterilized and used for one time.