Abstract
Pig faeces in which Ascaris suum eggs had been embryonating for 57 days were placed in buckets of soil containing either 30 or no earthworms (Aporrectodea longa). When present, earthworms consumed the faeces and transported the eggs down into the soil, without inflicting any visible damage on the eggs. In later experiments 10 earthworms from the above experiment were fed to each of ten pigs, and another 40 earthworms were dissected. None of the 10 pigs became infected with A. suum through consumption of earthworms, and none of the dissected earthworms were found to contain A. suum larvae. This experiment indicates that A. longa did not act as a paratenic host for A. suum but shows that earthworms are very efficient in transporting A. suum eggs from faeces deposited on the soil surface into the soil.
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Acknowledgements
Peter Holter of the University of Copenhagen is kindly acknowledged for his help in identifying the earthworms used in this experiment. This study was supported by The Danish National Research Foundation.
References
- Eriksen L, LindP, Nansen P, Roepstorff A, Urban J. Resistance to Ascaris suum in parasite naïve and naturally exposed growers, finishers and sows. Vet. Parasit. 1992;41:137–149. doi: 10.1016/0304-4017(92)90017-4. [DOI] [PubMed] [Google Scholar]
- Fries GF, Marrow GS, Snow PA. Soil ingestion by swine as a route of contaminant exposure. Environmental Toxicology and Chemistry. 1982;1:201–204. doi: 10.1897/1552-8618(1982)1[201:SIBSAA]2.0.CO;2. [DOI] [Google Scholar]
- Holter P. Effect of dung-beetles (Aphodius spp.) and earthworms on the disappearance of cattle dung. Oikos. 1979;32(3):393–402. doi: 10.2307/3544751. [DOI] [Google Scholar]
- Larsen MN. Master Thesis. Department of Population Biology. 1996. Arstidsvariation i overlevelse og ud-vikling for de frie larvestadier af 4 svineparasitter pa friland. (Seasonal variation in the survival and development of the free-living larval stages of 4 pig-parasites under outdoor conditions) [Google Scholar]
- Mizgajska H. The role of some environmental factors in the contamination of soil with Toxocara spp. and other geohelminth eggs. Parasitology International. 1997;46(1):67–72. doi: 10.1016/S1383-5769(97)00011-1. [DOI] [Google Scholar]
- Nielsen LB. Jordbundsokologi (Soil ecology) Kobenhavn: P. Haase & Sons Forlag; 1971. [Google Scholar]
- Roepstorff A, Nansen P: The epidemiology, diagnosis and control of helminth parasites of swine. A FAO handbook. FAO, Rome, (in press).
- Rysavy B. Lumbricidae - an important parasitological factor in helminthoses of domestic and wild animals. Pedobiologia. 1969;9:171–174. [Google Scholar]
- Seamster AP. Developmental studies concerning the eggs of Ascaris lumbricoides var suum. The American Midland Naturalist. 1950;43:450–470. doi: 10.2307/2421913. [DOI] [Google Scholar]
- Slotved H-C, Roepstorff A, Barnes EH, Eriksen L, Nansen P. Comparison of two methods for recovering migrating Ascaris suum larvae from the liver and lungs of pigs. J. parasit. 1996;82:612–615. doi: 10.2307/3283786. [DOI] [PubMed] [Google Scholar]
- Slotved H-C, Barnes EH, Eriksen L, Roepstorff A, Nansen P, Björn H. Use of agar-gel technique for large scale application to recover Ascaris suum larvae from intestinal contents of pigs. Acta vet. scand. 1997;38:207–212. doi: 10.1186/BF03548483. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Stoll NR. When are Ascaris eggs infective. J. Parasit. 1933;20:126. [Google Scholar]
- Szelagiewicz-Czosnek M. The role of the soil fauna in the epizootiology of the pig ascaridosis. II. Acta parasit. pol. 1972;20:173–177. [Google Scholar]
- Wharton DA. Ascaris sp.: Water loss during desiccation of embryonating eggs. Exp. Parasit. 1979;48:398–406. doi: 10.1016/0014-4894(79)90124-3. [DOI] [PubMed] [Google Scholar]