No one is trying to poison Catherine.
The poison is left over from an attempt on Henry.
His batshittedness which caused him to be murdered.
I actually took a break half way through, to get ice cream, lime if cared, so my mind thought over the facts at hand...
If Henry gave Catherine syphilis, then Kenna should have it, and she gave it to Bash.
But that's moot, because it's poison, and not the clap.
Here's laugh.
Only poor people ate mouldy bread.
But poor people had a hard enough time finding a wife.
I suppose if you spent all your money on prostitutes, that you'd eat mouldy bread, but the prostitutes who had all your money could always afford fresh bread, so it was the Johns who would swing through a never ending cycle of health and syphilis, because the whores (and the idle rich) would be eternally syphilitic.