Of course that's just the point. The PD hadn't been developed. And the point of the early seasons was to capture the naivete of the crew, and the dilemma's of interfering with a culture because they had to, wanted to, needed to, or just thought they were doing the right thing, versus the unknown ramifications of doing so.You can't explore and make contact the way Enterprise does if you held to a rigid "non-inteference" doctrine, it would force you into isolationism for fear you'd be interfering.
Just ftr...Kirk would have completly, utterly ignored it. McCoy wouldn't dream of bringing it up, and Spock..might...MIGHT, just for the sake of discussion, bring it up only to be shouted down.
TNG would have used the 'cry for help' as an excuse to get involved. If Beverly discovered the 'stagnant DNA', she would have ignored it. The crux of the drama would have probably been Picard ordering her to stop* until this case could have been ruled on and Beverly saying her Hippocratic oath supercedes her duty to Starfleet and threatens to resign.
*and we would have called it the stupidest thing ever. Much like that second season Ep with Data and the little alien girl.
I'm not using TNG or TOS to make a point, just to say how I think they would have handled it.