LH and Georgiansilver - Athlete's foot is a fungal infection - TRUE. It is also true that best conditions for it to take hold and thrive are when enclosed in warm damp sweaty footwear. Much less likely if feet do not sweat.
Transfer is very likely between people with sweaty enclosed feet - sporting types and changing room floors - athletes feet.
Antiperspirants and powders which absorb moisture can help limit transfer.
Once the initial damage to skin surface has happened, other usually harmless bacteria normally present on the skin surface get into the cracked skin and do further damage.

Urine is well known for use in medicine. Used in the past to sterilise surgical tools.
Urea is often the active ingredient for skin preparations - softening hard, cracked skin or ingrown toenails.

Quack!
GtD. (Damp feet, but no athlete).