The parasitic infections have traveled throughout the centuries at the forefront of the scourges afflicting the human race, surpassing even cancer, tuberculosis and plague. Not the least important of these are the helminth infections of the gastrointestinal tract, of which two, hookworm and schistosomiasis, are ranked with malaria as the most dangerous diseases of mankind.
Stoll1 estimated that there are 72,000,000 tapeworm, 148,000,000 fluke and more than 2,000,000,000 roundworm infections distributed throughout the world, a number exceeding the total of the world population. Well over half of these infections reside in the gastrointestinal tract. A not insignificant percentage of them is encountered in the United States and Canada. Again, he calculated that there are about 18,000,000 Enterobius, 2,000,000 hookworm, 3,000,000 Ascaris, 400,000 each of Trichuris and Strongyloides and 100,000 each of Taenia and Hymenolepis infections. The addition of 21,000,000 Trichinella infections elevates these already startling numbers to a really