If a dupe of Madrox were to be infected with some kind of poison, would Madrox Prime be infected with that same poison if he were to reabsorb the dupe? 

Yes.  In fact he did have to absorb a poisoned dupe during the ongoing X-Factor.  Normally, he'd create more duplicates in order to 'dilute' the poison's effect.  However, he couldn't at the time & therefore the main Madrox Prime became woosy & found it difficult to fight.

The same thing happens with broken bones.  He'll absorb the pain, if a bunch of healthy Madroxes aren't re-absorbed at the same time to dilute the pain & negative status effects.

In the first miniseries Jaime had absorbed a dupe who was passing away at the bar. That dupe was injured; the prime Madrox did not get any of his injuries or wounds when he absorbed it. So, he is immune to the injuries that his dupes have. On the other hand, as Xerox-Kitty pointed out, Jaime had been affected with some minor consequences that came from the absorption of his dupes as well  such as the M tattoo in his face.

So it’s really vague to know the right answer. Therefore as usual , it's not clear what consequences he can take or not.