The bacteria thing is something that's debated as much as the 'should you wash your cast iron with soap'. I don't have any references but if you google 'cast iron bacteria' you'll hit on a pile of pages with differing oppinions. Some say the pan gets so hot no bacteria can survive. But if the pan is not seasoned up or properly cleaned for that matter and you get bacteria in there during storage, you can get cross contamination when you pull it out, touch it, touch other food...touch yourself

I say better safe than sorry...especially if you're camping and the pan can come into contact with all kinds of things. As long as it's rightly seasoned and properly cleaned between uses (I like to scrub it down with a bit of coarse salt when water alone won't cut it) it's really a non issue.