I'm not a doc but I would argue that the guy must have had severe fungal infection of his feet to get to a point where sniffing his socks poses a health hazard.

I'm not a doc but I would argue that the guy must have had severe fungal infection of his feet to get to a point where sniffing his socks poses a health hazard. Maybe even immuno-compromised. I doubt you can contract this from healthy feet even if you sniff them daily :)