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Frequency distribution of Wuchereria bancrofti microfilariae in human populations and its relationships with age and sex

Published online by Cambridge University Press:  06 April 2009

P. K. Das ,
A. Manoharan ,
A. Srividya ,
B. T. Grenfell ,
D. A. P. Bundy  and
P. Vanamail
P. K. Das
Affiliation:
Vector Control Research Centre, Medical Complex, Indira Nagar, Pondicherry-605 006, India
A. Manoharan
Affiliation:
Vector Control Research Centre, Medical Complex, Indira Nagar, Pondicherry-605 006, India
A. Srividya
Affiliation:
Vector Control Research Centre, Medical Complex, Indira Nagar, Pondicherry-605 006, India
B. T. Grenfell
Affiliation:
Vector Control Research Centre, Medical Complex, Indira Nagar, Pondicherry-605 006, India Department of Zoology, University of Cambridge, Downing Street, Cambridge CB2 3EJ
D. A. P. Bundy
Affiliation:
Vector Control Research Centre, Medical Complex, Indira Nagar, Pondicherry-605 006, India Parasite Epidemiology Research Group, Department of Pure and Applied Biology, Imperial College, London SW7 2BB
P. Vanamail
Affiliation:
Vector Control Research Centre, Medical Complex, Indira Nagar, Pondicherry-605 006, India
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Summary

This paper examines the effects of host age and sex on the frequency distribution of Wuchereria bancrofti infections in the human host. Microfilarial counts from a large data base on the epidemiology of bancroftian filariasis in Pondicherry, South India are analysed. Frequency distributions of microfilarial counts divided by age are successfully described by zero-truncated negative binomial distributions, fitted by maximum likelihood. Parameter estimates from the fits indicate a significant trend of decreasing overdispersion with age in the distributions above age 10; this pattern provides indirect evidence for the operation of density-dependent constraints on microfilarial intensity. The analysis also provides estimates of the proportion of mf-positive individuals who are identified as negative due to sampling errors (around 5% of the total negatives). This allows the construction of corrected mf age–prevalence curves, which indicate that the observed prevalence may underestimate the true figures by between 25% and 100%. The age distribution of mf-negative individuals in the population is discussed in terms of current hypotheses about the interaction between disease and infection.

Keywords

Wuchereria bancroftilymphatic filariasisage distributionsex distributiontruncated negative binomialdensity dependence
Type
Research Article
Information
Parasitology , Volume 101 , Issue 3 , December 1990 , pp. 429 - 434
Copyright
Copyright © Cambridge University Press 1990

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References

REFERENCES

Anderson, R. M. & Gordon, D. M. (1982). The regulation of host population growth by parasite species. Parasitology 76, 119–57.CrossRefGoogle 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). Herd immunity to helminth infections and implications for parasite control. Nature, London 315, 493–6.CrossRefGoogle ScholarPubMed
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
Baker, D. & Nelder, J. A. (1978). GLIM Version 3.77 User Manual. Numerical Algorithms Group, Oxford.Google Scholar
Bunday, D. A. P. (1988). The population ecology of human helminth infections. Philosophical Transactions of the Royal Society of London, B 104, 214–17.Google Scholar
Crombie, J. A. & Anderson, R. M. (1985). Schistosoma mansoni infections in mice repeatedly exposed to infection. Nature, London 315, 491–3.CrossRefGoogle ScholarPubMed
Dietz, K. (1982 a). The population dynamics of onchocerciasis. In Population Dynamics of Infectious Diseases: Theory and Applications (ed. Anderson, R. M.) pp. 209–241. London: Chapman and Hall.CrossRefGoogle Scholar
Dietz, K. (1982 b). Overall population patterns in the transmission cycle of infectious disease agents. In Population Biology of Infectious Diseases (ed. Anderson, R. M. & May, R. M.), pp. 87–102. Berlin: Springer Verlag.CrossRefGoogle Scholar
Grenfell, B. T., Das, P. K., Rajagopalan, P. K. & Bundy, D. A. P. (1990). Frequency distribution of lymphatic filariasis microfilariae in human populations: population processes and statistical estimation. Parasitology 101, 417–27.CrossRefGoogle ScholarPubMed
Hairston, N. A. & Jachowski, L. A. (1968). Analysis of the W. bancrofti population in people of Western Samoa. WHO Bulletin 38, 29–59.Google Scholar
Otteson, E. A. (1984). Immunological aspects of lymphatic filariasis and onchocerciasis in man. Transactions of the Royal Society of Tropical medicine and Hygiene 78 (Suppl.), 9–18.CrossRefGoogle Scholar
Pacala, S. W. & Dobson, A. P. (1988). The relation between the number of parasites/host and host age: population dynamic causes and maximum likelihood estimation. Parasitology 96, 197–210.CrossRefGoogle ScholarPubMed
Park, C. B. (1988). Microfilarial density distribution in the human population and its infertility index for the mosquito population. Parasitology 96, 265–71.CrossRefGoogle Scholar
Rajagopalan, P. K. & Das, P. K. (1987). The Pondicherry Project on Integrated Disease Vector Control. Vector Control Research Centre, Pondicherry.Google Scholar
Sasa, M. (1976). Human Filariasis: a Global Survey of Epidemiology and Control. Tokyo: University of Tokyo Press.Google Scholar
Southgate, B. A. & Hamilton, P. J. S. (1974). Problems of clinical and biological measurements in the epidemiology and control of filarial infections. Transactions of the Royal Society of Tropical Medicine and Hygiene 68, 177–86.Google Scholar
Vanamail, P., Subramaniam, S., Das, P. K., Pani, S. P., Rajagopalan, P. K., Bundy, D. A. P. & Grenfell, B. T. (1990). Age-specific acquisition and loss of Wuchereria bancrofti infection in humans and estimation of the period of microfilarial production. Transactions of the Royal Society of Tropical Medicine and Hygiene (in the Press).Google Scholar