In mines, hookworm disease is well recognized as an occupational disease. Long before the cause was known, it was observed that the “miners' anemia” of Central and Northern Europe was unmistakably related to the occupation of mining, for people who did not go underground were not affected.
Even above ground hookworm disease may be an occupational disease in parts of the tropics and subtropics, especially among agricultural workers. After measuring the degree of infection of many peoplein Brazil by determining the number of hookworms expelled by treatment, Smillie has expressed the opinion that in the tropics and subtropics “hookworm disease is an occupational disease and is largely limited to soil workers.”
There are occupations other than mining and tilling the soil which have at times been found to favor the spread of hookworm infection even in regions where surface conditions would normally be unfavorable to the spread of infection, such, for example, as tunneling and brickmaking.