Something tells me that Delta IV isn't a tourist destination. IIRC, if an offworlder even tries to have sex with a Deltan, could be disastrous. Besides, Deltans probably don't much care for tourists anyway. Ilia may have been friendly when she said this but she did call humans a "sexually immature species"...that doesn't sound like anyone the Deltans would want hanging around (no pun intended).
I'd take the Shore Leave planet, where the fembots are sanitized for your protection. In a place like Risa, you don't know what you might catch.
Risa has got to have, what, a billion visitors a year? I'd just hazard a guess that every Risan gets a checkup for that reason alone.