They said that American Counter intelligence could recognize the poison which means that they had probably figured out a "good enough" cure from studying a number of victims, but an ER Doc is not going to ring the State Department enquiring after KGB counter measures... I think St Elsewhere started in 1984 and what passed for medicine back then was laughable... At least, what passed for dramatic fiction about medicine back then is laughable (I watched a couple seasons recently) and ailments that kept them flummoxed for entire episodes, 30 years later are throwaway lines on House or Greys Anatomy.
But if the State Department told EVERYONE... "This is a Poison the KGB uses to kill American citizens ALL THE TIME... Tell us if you find it, and here's the cure." It would lead to panic and war.
How many US Citizens on American soil are the KGB allowed to murder before Missiles are launched?
1? Maybe 2?
It's in America's best interest not to advertise the fact that these things are going on.