Hostname: page-component-cd9895bd7-hc48f Total loading time: 0 Render date: 2024-12-28T04:41:53.540Z Has data issue: false hasContentIssue false
  • English
  • Français

Non-linear phenomena in host—parasite interactions

Published online by Cambridge University Press:  06 April 2009

R. M. Anderson ,
R. M. May  and
S. Gupta
R. M. Anderson
Affiliation:
Department of Pure and Applied Biology, Imperial College, London University, London SW7 2BB
R. M. May
Affiliation:
Department of Zoology, Oxford University, South Parks Road, Oxford OX1 3PS
S. Gupta
Affiliation:
Department of Pure and Applied Biology, Imperial College, London University, London SW7 2BB
Get access Rights & Permissions [Opens in a new window]

Summary

The paper examines non-linear dynamical phenomena in host—parasite interactions by reference to a series of different problems ranging from the impact on transmission of control measures based on vaccination and chemotherapy, to the effects of immunological responses targeted at different stages in a parasite's life-cycle. Throughout, simple mathematical models are employed to aid in interpretation. Analyses reveal that the influence of a defined control measure on the prevalence or intensity of infection, whether vaccination or drug treatment, is non-linearly related to the magnitude of control effort (as defined by the proportion of individuals vaccinated or treated with a drug). Consideration of the relative merits of gametocyte and sporozoite vaccines against malarial parasites suggests that very high levels of cohort immunization will be required to block transmission in endemic areas, with the former type of vaccine being more effective in reducing transmission for a defined level of coverage and the latter being better with respect to a reduction in morbidity. The inclusion of genetic elements in analyses of the transmission of helminth parasites reveals complex non-linear patterns of change in the abundance of different parasite genotypes under selection pressures imposed by either the host immunological defences or the application of chemotherapeutic agents. When resistance genes are present in parasite populations, the degree to which abundance can be suppressed by chemotherapy depends critically on the frequency and intensity of application, with intermediate values of the former being optimal. A more detailed consideration of the impact of immunological defences on parasite population growth within an individual host, by reference to the erythrocytic cycle of malaria, suggests that the effectiveness of a given immunological response is inversely related to the life-expectancy of the target stage in the parasite's developmental cycle.

Keywords

host-parasite interactionsnon-linear relationshipsintestinal nematodesmathematical modelsimmunological responses
Type
Research Article
Information
Parasitology , Volume 99 , supplement S1: Symposium of the British Society for Parasitoiogy and the Linnean Society Special Issue: Research developments in the study of parasitic infections , January 1989 , pp. S59 - S79
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

REFERENCES

Anderson, R. M. (1982). Population Dynamics of Infectious Diseases: Theory and Applications. London: Chapman and Hall.Google Scholar
Anderson, R. M. & May, R. M. (1982). Population dynamics of human helminth infections: control by chemotherapy. Nature, London 297, 557–63.CrossRefGoogle ScholarPubMed
Anderson, R. M., & May, R. M. (1985 a). Vaccination and herd immunity to infectious disease. Nature, London 318, 323–9.CrossRefGoogle Scholar
Anderson, R. M. & May, R. M. (1985 b). Helminth infections of humans: mathematical models, population dynamics and control. Advances in Parasitology 24, 1–101.CrossRefGoogle ScholarPubMed
Anderson, R. M. & Medley, G. F. (1985). Community control of helminth infections of man by mass and selective chemotherapy. Parasitology 90, 629–60.CrossRefGoogle Scholar
Deans, J. A. & Cohen, S. (1983). Immunology of malaria. Annual Review of Microbiology 37, 25–49.CrossRefGoogle ScholarPubMed
Fisher, R. A. (1930). The Genetical Theory of Natural Selection. Oxford: Clarendon Press.CrossRefGoogle Scholar
Forsyth, K. P., Anderson, R. F., Kemp, D. J. & Alpers, M. P. (1988). New approaches to the serotypic analysis of the epidemiology of Plasmodium falciparum. In The Epidemiology and Ecology of Infectious Disease Agents (ed. Anderson, R. M. & Thresh, J. M.), pp. 159–165. London: The Royal Society.Google Scholar
May, R. M. (1977). Togetherness among schistosomes: its effects on the dynamics of the infection. Mathematical Biosciences 35, 301–43.CrossRefGoogle Scholar
May, R. M. & Hassell, M. P. (1988). Population dynamics and biological control. Philosophical Transactions of the Royal Society B 318, 129–69.Google Scholar
Molineaux, L. & Gramiccia, G. (1980). The Garki Project. Geneva: World Health Organization.Google Scholar
Ross, R. (1915). Some a priori pathometric equations. British Medical Journal 1, 546–7.CrossRefGoogle ScholarPubMed
Weinbaum, F. I., Evans, C. B. & Tigelaar, R. E. (1976). An in vitro assay for T-cell immunity to malaria in mice. Journal of Immunology 116, 1280–3.CrossRefGoogle Scholar
Zavala, F., Tam, J. P., Cochrane, A. H., Quakyi, I., Nussenweig, R. S. (1985). Rationale for development of a synthetic vaccine against Plasmodium falciparum malaria. Science 228, 1436–40.CrossRefGoogle ScholarPubMed