Do all sex toys have std's or does an infected person have to use it for it to be infected?

Dirty toys: The toy must be contaminated by an infected person. Of course, it is good to clean devices of regular bacteria before you use them.

Odd question: These toys do not come off the assembly line contaminated with germs. If used by someone with a STD the germ may remain alive for an extended period. Appropriate cleaning with soap & water & or steam will usually sterilize them.