You can get hookworms by walking barefoot over soil contaminated by the worm particularly through faeces. Your skin is usually penetrated by the hookworm larvae(immature worms) that may cause an allergic reaction. This is the itchy patch at the larvae entry point that gives early infection the name 'ground itch'. The larvae break through your skin, then enter your blood and are carried to your lungs and from your lungs to your windpipe and are then swallowed and carried back down to your small intestine.
Attribution: Avallain