On Star Trek, why wasn't Captain Kirk concerned with intergalactic venereal disease given that he has so many flings with alien chicks?

Because he had Bones there to treat it!

From the Star Trek Concordance Apocryphal Edition:

"Just as the technology behind the Interactive Voice Response system of the ship's computer was adapted and downsized for the Universal Translator, the ship's shield systems were the basis of the Universal Condom which is standard issue for all Starfleet Personnel.

Starfleet understands the importance and value of it's highly trained personnel to such a high degree that if a crew member's Universal Condom isn't in place at all times it is grounds for citation or even possible disciplinary action - up to and including being quartered in the brig where the old axiom of, 'If you drop your soap, don't pick it up!' still applies."

Any further questions? I still have this fine resource open!

Starfleet made sure to provide Kirk with extra lubricant, and made sure to keep him full of anti vd/std solutions.

OH, I know. I think stories of James T Kirk's sexual exploits were GREATLY exaggerated. His career is OBVIOUS over-compensation for something.

I guess ENTERPRISE was more brutally realistic: Trip Tucker got PREGNANT on his first inter-species date, and he never even (realized he) had sex.
let that be a lesson to us all.

Heck, if they don't even get colds anymore then why should they have VD issues? They did cure cancer in the future. Remember the episode from TNG where the Enterprise found the ship with all the Cryo people on it and revived all of them?

Be cause its f'ing captain kirk, he's a pimp of intergalactic proportions.

Because hes the Captain, and even STDs follow orders on the Enterprise.

STD's are species specific. A dog can't get a cold from Kirk and Kirk can't get herpes from a blue chick.

Because it's a tv show from the 1960's and not real life.