One thing bothers me - sometimes when I try to purify my team when they are 'ill', it doesn't work. And it's probably because one of them got ill once again and spread it across teammates :p So, my question is - do the corpses spread disease? If the answer is 'yes', then... I don't think I can purify those who are dead, right..?

Indeed, dead bodies spread disease and you can't purify them. Only one solution, run awayyyyy,

Thanks, that have been helpful