Guinea worm infestation is common in workers of:

Dracunculiasis or guinea worm disease is caused by the nematode Dracunculus medinensis, or Guinea worm. Infection occurs after swallowing water containing the infected intermediate host, the crustacean Cyclops (known as copepods or water fleas). The habit of washing and bathing in surface water and using step-wells is impoant for infestation. Ref: Park's textbook of Preventive and Social Medicine, 19th edition, Page 205.