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A model for variations in single and repeated egg counts in schistosoma mansoni infections

  • S. J. De Vlas (a1), B. Gryseels (a2), G. J. Van Oortmarssen (a1), A. M. Polderman (a2) and J. D. F. Habbema (a1)
  • DOI:
  • Published online: 01 April 2009

Faecal egg counts are often used to measure Schistosoma mansoni infection, but the considerable variation between successive counts complicates their interpretation. The stochastic model described in this paper gives a description of observed egg counts in a population and can be used as a tool to gain an insight into the underlying worm load distribution. The model distinguishes between two sources of variation in egg counts: (1) variation caused by the difference in worm load between individuals, and (2) the variability of egg counts for an individual with a given worm load. Empirical data, single and repeated measurements, from surveys in five villages in Burundi and Zaire have been used to fit and validate the model. We have discussed possible mechanisms that explain the differences in estimated values between the villages. The model indicates that the expected number of eggs in a stool sample per S. mansoni worm pair is lower than suggested by autopsy data and that, possibly as a consequence of immunity, the inter-individual variation in worm loads decreases with age.

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R. M. Anderson & R. M. May (1985). Helminth infections of humans: mathematical models, population dynamics, and control. In Advances in Parasitology, Vol. 24 (ed. J. R. Baker & R. Muller ), pp. 1101. London: Academic Press.

M. L. Barreto , J. T. F. Silva , K. E. Mott & J. S. Lehman (1978). Stability of faecal egg excretion in Schistosoma mansoni infection. Transactions of the Royal Society of Tropical Medicine and Hygiene 72, 181–7.

D. J. Bradley (1972). Regulation of parasite populations: a general theory of the epidemiology and control of parasitic infections. Transactions of the Royal Society of Tropical Medicine and Hygiene 66, 697708.

D. J. Bradley & R. M. May (1978). Consequences of helminth aggregation for the dynamics of schistosomiasis. Transactions of the Royal Society of Tropical Medicine and Hygiene 72, 262–73.

A. E. Butterworth , M. Capron , J. S. Cordingley , P. R. Dalton , D. W. Dunne , H. C. Kariuki , G. Kimani , D. Koech , M. Mugambi , J. H. Ouma , M. A. Prentice , B. A. Richardson , T. K. Arap Siongok , R. F. Sturrock & D. W. Taylor (1985). Immunity after treatment of human schistosomiasis mansoni. II. Identification of resistant individuals, and analysis of their immune responses. Transactions of the Royal Society of Tropical Medicine and Hygiene 79, 393408.

D. R. Cox & D. V. Hinkley (1974). Theoretical Statistics. London: Chapman and Hall.

B. Gryseels (1988). The morbidity of schistosomiasis mansoni in the Rusizi Plain (Burundi). Transactions of the Royal Society of Tropical Medicine and Hygiene 82, 582–7.

B. Gryseels & A. M. Polderman (1987). The morbidity of schistosomiasis mansoni in Maniema (Zaire). Transactions of the Royal Society of Tropical Medicine and Hygiene 81, 202–9.

B. Gryseels & A. M. Polderman (1991). Morbidity and morbidity control of schistosomiasis mansoni in Subsaharan Africa. Parasitology Today 7, 244–8.

G. Macdonald (1965). The dynamics of helminth infections, with special reference to schistosomes. Transactions of the Royal Society of Tropical Medicine and Hygiene 59, 489506.

R. M. May (1977). Togetherness among schistosomes: its effects on the dynamics of the infection. Mathematical Biosciences 35, 301–43.

G. Medley & R. M. Anderson (1985). Density-dependent fecundity in Schistosoma mansoni infections in man. Transactions of the Royal Society of Tropical Medicine and Hygiene 79, 532–4.

I. Nasell & W. M. Hirsch (1973). The transmission dynamics of schistosomiasis. Communications on Pure and Applied Mathematics 26, 395453.

C. H. Teesdale , K. Fahringer & L. Chitsulo (1985). Egg count variability and sensitivity of a thin smear technique for the diagnosis of schistosomiasis mansoni. Transactions of the Royal Society of Tropical Medicine and Hygiene 79, 369–73.

K. S. Warren (1973). Regulation of the prevalence and intensity of schistomiasis in man: immunology or ecology? Journal of Infectious Diseases 127, 595609.

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