Had a similar but slightly more catastrophic issue with a barrel full of Munton's Oaked Ale. The barrel was sitting on the garage floor and I accidently kicked the tap causing it to jump the thread on the back nut. Beer squirting everywhere so I quickly poured it all into a clean fermenter, sorted the barrel out and syphoned it back in again. Should have reprimed as it wasn't as carbonated as I'd have liked.
After having mentioned it on here many said just to give you hands and arm a good scrub possibly followed by a rinse of StarSan solution then just shove your hand in and tighten it up. It'll more than likely be okay. Beer is more likely to get infected during fermentation, once it has fermented the alcohol is acting as a preservative.