[poloniculmov]

Brewed beer can get yeast or bacterial infections, especially if you cannot refrigerate it and don't have the means to sanitize recipients.

[larsga]

Yes, it can. But infections by harmful organisms is very difficult to achieve. The common spoilage organisms in beer are all harmless to humans. Here's a good overview http://mmbr.asm.org/content/77/2/157.long

Just the hops alone stop pretty much all gram-positive bacteria except Lactobacillus and a few other harmless ones.