1.Hookworm surveys in eight southern states were made during the periods 1910–1914 and 1930–1938. In the early period, 577,590 specimens of feces were examined, and in the later period, 424,511. The numbers found positive in the early and later periods were 240,895 and 81,913 respectively.
2.After adjustment for the distribution of the population the percentage found positive in six of the eight states was 36.6 per cent in the earlier period and 11.2 per cent in the later period, resulting in a reduction of 68.3 per cent.
3.In the later study the states in the order of prevalence from highest to lowest were as follows: Mississippi, South Carolina, Alabama, North Carolina, Kentucky and Tennessee.
4.While there is a widespread distribution of hookworm, the areas of highest incidence are confined to the coastal plain and sandy soil areas of each state.
5.The age distribution shows that the greatest prevalence was in the group 5 to 19 years of age. The peak of incidence, 24.5 per cent, was reached in the age period 15 to 19. In preschool children and adults the incidence was about one-half as great as that found in the school age group.
6.The distribution of all positive cases shows that about one-fourth of the individuals had moderate, heavy or very heavy worm infestations sufficiently severe to produce clinical symptoms. The remainder of the cases were classified as very light or light infestations.
7.The data analyzed with reference to household groups seemed to indicate that the individual worm burden tended to increase as the number of infested persons in the family increased.
8.A comparison was made of hookworm in 17,458 negroes and 59,028 white persons in the same counties during 1930–1938. The incidence in negroes was about one fourth that in white individuals and the average intensity of infestation was about one-half that found in white persons.