Hostname: page-component-586b7cd67f-t8hqh Total loading time: 0 Render date: 2024-11-23T02:12:06.707Z Has data issue: false hasContentIssue false
  • English
  • Français

The weight/length profiles of Ascaris lumbricoides within a human community before mass treatment and following reinfection

Published online by Cambridge University Press:  06 April 2009

D. B. Elkins  and
M. Haswell-Elkins
D. B. Elkins
Affiliation:
Parasite Epidemiology Research Group, Department of Pure and Applied Biology, Imperial College, University of London, London SW7 2BB
M. Haswell-Elkins
Affiliation:
Parasite Epidemiology Research Group, Department of Pure and Applied Biology, Imperial College, University of London, London SW7 2BB
Get access Rights & Permissions [Opens in a new window]

Summary

Weight and length profiles are presented of 3505 Ascaris worms recovered after mass anthelmintic treatment of a human community in January 1984 and, after an 11 month period of reinfection, in November 1984. Male and female worms recovered after reinfection were significantly heavier and longer than those expelled after initial treatment (P < 0·0001). Multiple regression models were employed to examine variability in parasite size. A positive influence of host body weight on the weight of parasites recovered in January, but not in November, was observed. No negative relationship was recorded at either date between worm size and the total number of worms harboured, even after controlling for host weight. Striking host age-related variability was observed in the distribution profile of weights and lengths of individual worms recovered in January. Children harboured predominantly smaller worms before initial treatment, while adults expelled mainly heavy worms. In contrast, worms expelled by both children and adults after reinfection were heavier and more homogeneous in size, particularly within the relatively heavily infected group. These patterns argue against a primary role for density- dependent or acquired resistance mechanisms in determining the size of Ascaris in humans. However, the results are consistent with a hypothesis initially suggested by Jung (1954) that established worms may inhibit the development of newly acquired Ascaris larvae, perhaps regulating their own abundance.

Keywords

Ascaris lumbricoidesweight profileslength profilesanthelmintic treatment
Type
Research Article
Information
Parasitology , Volume 99 , Issue 2 , October 1989 , pp. 293 - 299
Copyright
Copyright © Cambridge University Press 1989

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Arfaa, F. & Ghadirian, E. (1977). Epidemiology and mass treatment of ascariasis in six rural communities in Central Iran. American Journal of Tropical Medicine and Hygiene 26, 866–71.CrossRefGoogle ScholarPubMed
Baird, J. K., Mistrey, M., Pimsler, M. & Connor, D. H. (1986). Fatal human ascariasis following secondary massive infection. American Journal of Tropical Medicine and Hygiene 35, 314–18.CrossRefGoogle ScholarPubMed
Beaver, P. C. (1952). Observations on the epidemiology of ascariasis in a region of high hookworm endemicity. Journal of Parasitology 38, 445–53.CrossRefGoogle Scholar
Behnke, J. M. & Parish, H. A. (1979). Nematospiroides dubius: The arrested development of larvae in immune mice. Experimental Parasitology 47, 116–18.CrossRefGoogle ScholarPubMed
Cho, S. Y. (1977). Study on the quantitative evaluation of reinfection of Ascaris lumbricoides. Korean Journal of Parasitology 15, 17–29.CrossRefGoogle Scholar
Crandall, C. A. & Arean, V. M. (1964). The protective effect of viable and nonviable Ascaris suum larvae and egg preparations in mice. American Journal of Tropical Medicine and Hygiene 14, 765–9.CrossRefGoogle Scholar
Elkins, D. B., Haswell-Elkins, M. R. & Anderson, R. M. (1986). The epidemiology and control of intestinal helminths in the Pulicat Lake region of Southern India. I. Study design and pre- and post-treatment observations on Ascaris lumbricoides infection. Transactions of the Royal Society of Tropical Medicine and Hygiene 80, 774–92.CrossRefGoogle Scholar
Elkins, D. B., Haswell-Elkins, M. R. & Anderson, R. M. (1988). The importance of host age and sex to patterns of reinfection with Ascaris lumbricoides following mass anthelmintic treatment in a South Indian fishing community. Parasitology 96, 171–84.CrossRefGoogle Scholar
Gibbs, H. C. (1986). Hypobiosis in parasitic nematodes — an update. Advances in Parasitology 25, 129–74.CrossRefGoogle ScholarPubMed
Gibson, T. E. (1953). The effect of repeated anthelmintic treatment with phenothiazine on the faecal egg counts of housed horses with some observations on the life cycle of Trichonema spp. in the horse. Journal of Helminthology 27, 29–40.Google Scholar
Holmes, J. C. (1959). Interaction between dietary carbohydrate quality and quantity in nutrition of Hymenolepis diminuta. Journal of Parasitology 45, 31.Google Scholar
Jung, R. C. (1954). The predominance of single-brood infections in human ascariasis. Journal of Parasitology 40, 405–7.CrossRefGoogle ScholarPubMed
Martin, J., Keymer, A., Isherwood, R. J. & Wainwright, S. M. (1984). The prevalence and intensity of Ascaris lumbricoides infections in Moslem children from northern Bangladesh. Transactions of the Royal Society of Tropical Medicine and Hygiene 77, 702–6.CrossRefGoogle Scholar
Mello, D. A. (1974). A note on the egg production of Ascaris lumbricoides. Journal of Parasitology 60, 380–1.Google Scholar
Michel, J. F. (1974). Arrested development of nematodes and some related phenomena. Advances in Parasitology 12, 279–366.CrossRefGoogle ScholarPubMed
Pawlowski, Z. S. & Arfaa, F. (1984). Nematode infections: ascariasis. In Tropical and Geographical Medicine, (ed. Warren, K. S. & Mahmoud, A. A. F.) New York: McGraw-Hill Book Company.Google Scholar
Roberts, L. S. & Mong, F. N. (1968). Developmental physiology of cestodes. III. Development of Hymenolepis diminuta in superinfection. Journal of Parasitology 54, 55–62.CrossRefGoogle Scholar
Schad, G. A., Chowdhury, A. B., Dean, C. J., Kochar, V. K., Nawalinski, T. A., Thomas, J. & Tonascia, J. A. (1973). Arrested development in human hookworm infections. An adaptation to a seasonally unfavourable external environment. Science 180, 502–4.CrossRefGoogle ScholarPubMed
Seo, B. S., Cho, S. Y. & Chai, J. Y. (1979). Frequency distribution of Ascaris lumbricoides in rural Koreans with special reference to the effect of changing endemicity. Korean Journal of Parasitology 17, 105–13.Google Scholar
Seo, B. A., Cho, S. Y. & Chai, J. Y. (1980). The growth curve of Ascaris lumbricoides with consideration of the prepatent period. Korean Journal of Parasitology 18, 262.Google Scholar
Soulsby, E. J. L. (1961). Some aspects of the mechanism of immunity to helminths. Journal of the American Veterinary Medical Association 138, 355–62.Google Scholar
Sprent, J. F. A. & Chan, H. H. (1949). Immunological studies in mice infected with the larvae of Ascaris lumbricoides. I. Criteria of immunity and immunizing effect of isolated worm tissues. Journal of Infectious Diseases 84, 111–24.Google Scholar
Taliaferro, W. H. & Sarles, M. P. (1939). The cellular reactions in the skin, lungs and intestine of normal and immune rats after infection with Nippostrongylus muris. Journal of Infectious Diseases 64, 157–92.CrossRefGoogle Scholar
Wakelin, D. (1978). Immunity to intestinal parasites. Nature, London 273, 617–20.CrossRefGoogle ScholarPubMed