Roundworms (Ascaris lumbricoides) are fairly large worms (10 inches in length) which parasitize the human host by eating semi-digested food in the small intestine. The females can lay 200,000 eggs per day for a lifetime total of 26 million or so. Larvae develop from the eggs in soil under favorable conditions (21°C to 30°C / 69.8°F to 86°F). Above 37°C (98.6°F), they cannot fully develop.
Approximately 900 million people are infected with roundworms worldwide, one million in the US. The eggs are usually transmitted hand to mouth by people, usually children, who have come into contact with the eggs in their environment. Infected persons usually complain of a vague abdominal pain. Diagnosis is by stool analysis.39 An analysis of 400,000 stool samples throughout the US by the Center for Disease Control found Ascaris in 2.3% of the samples, with a wide fluctuation in results depending on the geographical location of the person sampled. Puerto Rico had the highest positive sample frequency (9.3%), while samples from Wyoming, Arizona, and Nevada showed no incidence of Ascaris at all.40 In moist tropical climates, roundworm infection may afflict 50% of the population.41
Eggs are destroyed by direct sunlight within 15 hours, and are killed by temperatures above 40°C (104°F), dying within an hour at 50°C (122°F). Roundworm eggs are resistant to freezing temperatures, chemical disinfectants, and other strong chemicals, but thermophilic composting will kill them.
Roundworms, like hookworms and whipworms, are spread by fecal contamination of soil. Much of this contamination is caused and spread by children who defecate outdoors within their living area. One sure way to eradicate fecal pathogens is to conscientiously collect and thermophilically compost all fecal material. Therefore, it is very important when composting humanure to be certain that all children use the toilet facility and do not defecate elsewhere. When changing soiled diapers, deposit the fecal material into the humanure receptacle with toilet paper or another biodegradable material. It's up to adults to keep an eye on kids and make sure they understand the importance of always using a toilet facility.
Fecal environmental contamination can also be caused by using raw fecal material for agricultural purposes. Proper thermophilic composting of all fecal material is essential for the eradication of fecal pathogens.
Source: The Humanure Handbook. Jenkins Publishing, PO Box 607, Grove City, PA 16127. To order, phone: 1-800-639-4099.