Forum adverts like this one are shown to any user who is not logged in. Join us by filling out a tiny 3 field form and you will get your own, free, dakka user account which gives a good range of benefits to you: No adverts like this in the forums anymore. Times and dates in your local timezone. Full tracking of what you have read so you can skip to your first unread post, easily see what has changed since you last logged in, and easily see what is new at a glance. Email notifications for threads you want to watch closely. Being a part of the oldest wargaming community on the net. If you are already a member then feel free to login now.

In the codex it says any cultist in the army may become plague zombies, by 7th edition rule book that would mean its cross detachment for example a detachment of Death guard with typhus and a detachment of alpha legion with cultists. From my understanding the cultists could become zombies or am i missing a rule somewhere?

Correct.