As far as bad eggs go, the bacteria is in the shell, and desn’t respect boundaries there, either. Studies have shown that eggs from “free range hens” are not significantly safer than those from factory-raised hens, but that seems to me a bit misleading: “free range” means that there’s access to the outside from the warehouse where the hens are stored, but the hens are (according to what I’ve read) not apt to take advantage of it, thus the only difference between the two environments is lack of a cage: the hens are still huddled in a building eating a diet consisting entirely of feed.

Actual farm-raised hens, though, scratch around the outside, eat a diet that consists in large part of things they find (supplemented by feed), and have a much more open, natural environment. Therefore, in my estimation, are healthier. Even if that’s not the case, though, the fresher the egg, the better it is, thus the large difference in time between when the egg is laid and when it gets to you is very significant.

http://nymag.com/restaurants/features/30005/

Lauren - I think that if we all knew that bacteria lived on the outside, maybe we (in the general America sense) wouldn’t eat so many fast food hamburgers that are who knows how old. my friend’s microbiologist sister is famous (in my head) for pointing out it’s all about surface area! keep it small and there’s less chance you’ll find a microbug waiting to give you gastrointestinal issues.