Investigations were made on the concentrations of aqueous solutions of iodine required to kill the infective stages of Necator americanus, Ancylostoma caninum, Strongyloides stercoralis, Ascaris lumbricoides, Toxocara canis and Trichuris muris. Solutions containing 70 ppm free iodine, prepared by dissolving tablets of Globaline® or Heliogen® in distilled water, killed the infective free larvae of hookworms and Strongyloides within 5 minutes or less at temperatures ranging from 15°C to 30°C. To kill infective larvae in the eggs of Ascaris, Toxocara and Trichuris under similar conditions concentrations of 100, 120, and 250 ppm, respectively, were required. Killing action was more rapid at the low than at the high temperatures. Solutions at concentrations up to 500 ppm did not adversely affect the flavor or appearance of any of the common types of leafy or rooty vegetables. Solutions of sufficient strength to kill the eggs and larvae of these worms, and at the same time to destroy the common enteric microorganisms, are easily prepared and therefore appear to be suitable for the disinfection of vegetables to be consumed in the fresh state.
Present address: Department of Pathology, Siriraj Hospital Medical School, Bangkok, Thailand.