Find another hobby. Contracting an STD from a random girl you met outside of the industry, is far more likely, and a bigger risk, than contracting an STD from a well known Service Provider or Agency. Professional SP's take better care of themselves, are tested regularly, far more than the majority of those outside of the industry. With that being said, if you want to through caution to the wind and see SP's with drug issues, Track Workers, late night SP's advertising "Party Friendly" then perhaps being "Super" paranoid is how you should be.
Bob