Almost everyone has been it, diseased and/or poisoned. We all know the messages when you feel another stream of illness go through your body. You know you're sick, but others wont notice it. I find that pretty strange, since poison and disease are not the lightest of illnesses and when you walk with someone you could surely notice it (besides that the person stops following you sometimes when he's diseased). So my suggestion is that chars who are poisoned or diseased automaticly turn white in skin or puke once in a while....well, showing signs of their illness. That way others can actually see you are sick, makes it more realistic. Could also do this when you are better again. OR...make a better command. When someones feels better enough, you can use the command to let your companions know.
[103 H 34 M] Better
You make a little movement, indicating you're feeling better again.
That command can also be done after hard beating during fights. After that person healed up a bit, feeling strong enough to fight again, he could use that command.
Of course you could do this with emotes, but i can imagine you are not always in the mood. Looks a bit like forced rp, but i think it will the opposite...that it will stimulate others more to rp. It makes it easier to start rp-ing for starters as the messages are a little help so that they can rp around it and not have to start from scratch which can be really hard sometimes.