King Daniel Into Darkness wrote:
As for Marla, we have no clue how she died. If it was brain bugs, I doubt healing blood would cure madness - if anything (as we may see in STXIII), it'd cause it.
Actually, Khan does say that it was the Ceti eel which killed McGivers ("it killed twenty of my people...including my beloved wife"). And if he had used his blood to treat her, it might have caused her body to expel or kill the eel as a foreign substance.