I saw an episode of Survivorman where Les Stroud caught a rodent in the southwest desert. He did eat it but wouldn't touch it with his bare hands till he thoroughly cooked it without skinning it.
Fleas are fairly motile, though. Any proximity to an animal carrying plague-ridden fleas might be sufficient for them to “jump ship” right onto you.
Looks very much like a map of travel from Mexico to north of the border.