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Density-dependent effects on establishment of Necator americanus and Ancylostoma ceylanicum

Published online by Cambridge University Press:  05 June 2009

S. M. B. Norozian-Amiri
Affiliation:
MRC Experimental Parasitology Group, Department of Life Science, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
J. M. Behnke*
Affiliation:
MRC Experimental Parasitology Group, Department of Life Science, University of Nottingham, University Park, Nottingham, NG7 2RD, UK
*
* Author to whom all correspondence should be addressed.

Abstract

The relationships between the number of infective larvae (L3s) to which animals were exposed and the establishment of A. ceylanicum and N. americanus in hamsters were examined. There was no evidence of density-dependent constraints on the establishment of A. ceylanicum in the range 10–1000 larvae, but an experiment in which the range was extended to 1500 L3s gave a significant negative correlation between the magnitude of the infecting dose and percentage establishment. Even so the percentage reduction was relatively small, approximating to 0·89% per 100 larvae administered, and in practice density-dependent constraints on establishment are unlikely to affect experiments with this species in which much lower doses (<250 L3) are generally employed. The range of doses for N. americanus L3s was smaller (10–400). Of the four experiments reported, two gave a significant reduction of establishment with increasing dose and two did not. When the data was split into low doses (<100 L3s) and high doses (>100 L3s), falling establishment with increasing dose was only detected in the lower dose range. There was no difference in the establishment when doses of 100 L3s were compared with 250 or 400 L3s. On balance, it was concluded that density-dependent constraints on establishment of N. americanus in hamsters were not marked and would have little significant effect on experiments utilizing fewer than 200 L3s (approximately 7·6% reduction between 10 and 200 L3s). These results are discussed in relation to host regulation of hookworm burdens.

Type
Research Papers
Copyright
Copyright © Cambridge University Press 1993

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References

Anderson, R. M. & May, R. M. (1985) Helminth infections of humans: mathematical models, population dynamics and control. Advances in Parasitology, 24, 1101.Google Scholar
Behnke, J. M. (1987) Do bookworms elicit protective immunity in man? Parasitology Today, 3, 200206.CrossRefGoogle Scholar
Behnke, J. M. (1990) Laboratory animal models. In: Hookworm Disease. Current Status and New Directions. pp. 105128 (editors, Schad, G. A. and Warren, K. S.). Taylor and Francis: London, UK.Google Scholar
Behnke, J. M. (1991) Immunology. In: Human Parasitic Diseases, Volume 4, Hookworm Infections. pp. 93155 (editors, Gilles, H. M. and Ball, P. A. J.). Elsevier: Amsterdam.Google Scholar
Behnke, J. M., Paul, V. & Rajasekariah, G. R. (1986a) The growth and migration of Necator americanus following infection of neonatal hamsters. Transactions of the Royal Society of Tropical Medicine and Hygiene, 80, 146149.Google Scholar
Behnke, J. M., Wells, C. & Brown, J. (1986b) An improved technique for experimental infections with skin penetrating nematode larvae (Necator americanus). International Journal for Parasitology, 16, 461464.CrossRefGoogle ScholarPubMed
Bundy, D. A. P. (1990) Is the hookworm just another geohelminth? In: Hookworm Disease. Current Status and New Directions. pp. 147164. (editors, Schad, G. A. and Warren, K. S.). Taylor and Francis: London, UK.Google Scholar
Bundy, D. A. P. & Keymer, A. E. (1991) The epidemiology of hookworm infection. In: Human Parasitic Diseases, Volume 4, Hookworm Infections. pp. 157178. (editors, Gilles, H. M. and Ball, P. A. J.). Elsevier: Amsterdam.Google Scholar
Carroll, S. M. & Grove, D. I. (1984) Parasitological, hematologic and immunologic responses in acute and chronic infections of dogs with Ancylostoma ceylanicum: a model of human hookworm infection. Journal of Infectious Diseases, 150, 284294.CrossRefGoogle Scholar
Garside, P. & Behnke, J. M. (1989) Ancylostoma ceylanicum: observations on host–parasite relationship during primary infection. Parasitology, 98, 283289.CrossRefGoogle ScholarPubMed
Keymer, A. (1982) Density-dependent mechanisms in the regulation of intestinal helminth populations. Parasitology, 84, 573587.CrossRefGoogle ScholarPubMed
Keymer, A. & Slater, A. F. G. (1987). Helminth fecundity: density dependence or statistical illusion? Parasitology Today, 3, 5658.CrossRefGoogle ScholarPubMed
Krupp, I. M. (1961) Effects of crowding and of superinfection on habitat selection and egg production in Ancylostoma caninum. Journal of Parasitology, 47, 957961.CrossRefGoogle ScholarPubMed
Michael, E. & Bundy, D. A. P. (1989) Density dependence in establishment, growth and worm fecundity in intestinal helminthiasis: the population biology of Trichuris muris (Nematoda) infection in CBA/Ca mice. Parasitology, 98, 451458.Google Scholar
Onwuliri, C. O. E., Nwosu, A. B. C. & Anya, A. O. (1981) Experimental Ancylostoma tubaeforme infection of cats: changes in blood values and worm burden in relation to single infections of varying size. Zeitschrift für Parasitenkunde, 64, 149155.CrossRefGoogle ScholarPubMed
Rajasekariah, G. R., Deb, B. N., Dhage, K. R. & Bose, S. (1985) Site of resistance to Necator americanus in hamsters. Acta Tropica, 42, 333340.Google ScholarPubMed
Ray, D. K., Bhopale, K. K. & Shrivastava, V. B. (1972) Migration and growth of Ancylostoma ceylanicum in golden hamsters. Journal of Helminthology, 46, 357362.CrossRefGoogle ScholarPubMed
Rose, R. A. & Behnke, J. M. (1990) Necator americanus in the DSN hamster: density dependent expulsion of adult worms during primary infection. Parasitology, 100, 469478.CrossRefGoogle ScholarPubMed
Sarles, M. P. (1929) The effect of age and size of infestation on the egg production of the dog hookworm, Ancylostoma caninum. American Journal of Hygiene, 10, 658666.Google Scholar
Schad, G. A. & Warren, K. S. (editors) (1990) Hookworm Disease: Current Status and New Directions. Taylor & Francis: London.Google Scholar
Sen, H. G. (1972) Necator americanus: behaviour in hamsters. Experimental Parasitology, 32, 2632.Google Scholar
Sokal, R. R. & Rohlf, F. J. (1969) Biometry. Freeman: San Francisco.Google Scholar