Perhaps I should have stated that hookworm infections of clinical significance are extremely rare in the US at the present time instead of simply saying that hookworm infections are rare.
The Florida State Board of Health has reported that in 1950, of 130,000 stool examinations, 24,248 were positive for hookworm eggs; in 1955, of 136,000, 13,121 were positive; and in 1962, of 125,000, only 7,000 were positive. It is evident that there has been a continued and striking decline in infections. Further, data are available from studies of men enlisting in the US armed services during World War II. Hookworm infections may have been relatively prevalent in some Southeastern states; however, a comparison of men from areas of hookworm infection with men from other areas as to results of IQ and other performance tests, height, weight, and hemoglobin level showed that these infections were of no clinical significance.