These eggs exit from the body in the feces and are then deposited on the ground. Under the warm, shady and moist soil conditions common in rural areas of the tropics and subtropics, the eggs hatch and release immature larval worms that molt to become third-stage infective larvae or L3. Transmission of the L3 to humans can occur by two routes. L3 can infect a susceptible individual by directly penetrating the skin. Or, in the case of A. duodenale , the more virulent species, they can also be swallowed.
Oral ingestion is believed to be a significant route of transmission.
The adverse consequences of hookworms on maternal-child health During the early part of the 20th century, hookworm was recognized for its ability to impair the growth and physical fitness of children. Using traditional sanitary control measures and anthelminthic drugs, the International Health Board of the Rockefeller Foundation launched aggressive campaigns to combat hookworm infection. However, these efforts did not have a sustainable impact on the global prevalence and intensity of hookworm. Over time, hookworm control became unfashionable, partly because it was considered an insoluble public health problem and therefore was not worthy of aggressive intervention, even though its impact on child and maternal health never diminished. In subsequent decades, many sectors of the international public health community underestimated the importance of hookworm.