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Inoculum size, incubation period and severity of malaria. Analysis of data from malaria therapy records

Published online by Cambridge University Press:  06 April 2009

J. R. Glynn  and
D. J. Bradley
J. R. Glynn
Affiliation:
Department of Epidemiology and Population Sciences, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT
D. J. Bradley
Affiliation:
Department of Epidemiology and Population Sciences, London School of Hygiene and Tropical Medicine, Keppel Street, London WC1E 7HT
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Extract

The size of the infecting inoculum may influence the severity of malaria, but evidence is scarce. Malaria therapy records provide a unique source of information on induced malaria in people. The therapy was given to large numbers of neurosyphilis patients and the malaria was left untreated as long as possible. Data from patients treated at the Horton Hospital, Epsom 1923–60 with a single strain of vivax malaria were analysed to assess the influence of inoculum size on severity of disease. Malaria was induced by mosquito bite, blood inoculation or direct sporozoite inoculation. The different measures of inoculum size were inversely correlated with pre-patent period, as expected. Overall, information was available on a total of 563 non-immune patients who were not treated during the first 5 days of patent parasitaemia. No strong or consistent relationships were found between measures of inoculum size and any of the measures of severity used: neither parasitaemia levels, nor peak fevers, nor number of paroxysms of fever. In the largest data set, longer pre-patent periods were associated with tertian fever, spontaneous recovery and less use of modifying treatment. Difficulties in interpreting the results are discussed, particularly with respect to misclassification of both exposure and outcome variables. While an inoculum size-severity relationship cannot be ruled out, a strong relationship is very unlikely.

Keywords

malariainoculum sizeincubation periodpre-patent perioddisease severitymalaria therapy
Type
Research Article
Information
Parasitology , Volume 110 , Issue 1 , January 1995 , pp. 7 - 19
Copyright
Copyright © Cambridge University Press 1995

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References

REFERENCES

Beier, J. C., Onyango, F. K., Koros, J. K., Ramadhan, M., Ogwang, R., Wirtz, R. A., Koech, D. K. & Roberts, C. R. (1991 a). Quantitation of malaria sporozoites transmitted in vitro during salivation by Afrotropical anopheles. Medical and Veterinary Entomology 5, 71–9.CrossRefGoogle ScholarPubMed
Beier, J. C., Davis, J. R., Vaughan, J. A., Noden, B. H. & Beier, M. S. (1991 b). Quantitation of Plasmodium falciparum sporozoites transmitted in vitro by experimentally infected Anopheles gambiae and Anopheles stephensi. American Journal of Tropical Medicine and Hygiene 44, 564–70.CrossRefGoogle ScholarPubMed
Bermejo, A. & Veeken, H. (1992). Insecticide-impregnated bed nets for malaria control: a review of the field trials. Bulletin of the World Health Organization 70, 293–6.Google ScholarPubMed
Boyd, M. F. & Kitchen, S. F. (1937). A further note on the infectiousness of Anopheline mosquitoes infected with P. vivax and P. falciparum. American Journal of Tropical Medicine 17, 245–51.Google Scholar
Craige, B., Alving, A. S., Jones, R., Whorton, C. M., Pullman, T. N. & Eichelberger, L. (1947). The Chesson strain of Plasmodium vivax malaria II. Relationship between prepatent period, latent period and relapse rate. Journal of Infectious Diseases 80, 228–36.CrossRefGoogle Scholar
Glynn, J. R. (1993). Studies on the influence of infecting dose on the severity of disease. Ph.D. thesis, University of London.Google Scholar
Glynn, J. R. (1994). Infecting dose and severity of malaria: a literature review of induced malaria. Journal of Tropical Medicine and Hygiene (in the Press).Google ScholarPubMed
Greenwood, B., Marsh, K. & Snow, R. (1991). Why do some African children develop severe malaria. Parasitology Today 7, 277–81.CrossRefGoogle ScholarPubMed
James, S. P., Nicol, W. D. & Shute, P. G. (1927). Notes On a new procedure for malaria research. Transactions of the Royal Society of Tropical Medicine and Hygiene 21, 233–6.CrossRefGoogle Scholar
James, S. P. (1931). Some general results of a study of induced malaria in England. Transactions of the Royal Society of Tropical Medicine and Hygiene 24, 477–538.CrossRefGoogle Scholar
James, S. P., Nicol, W. D. & Shute, P. G. (1936). Clinical and parasitological observations on induced malaria. Proceedings of the Royal Society of Medicine 29, 879–94.CrossRefGoogle ScholarPubMed
Marsh, K. (1992). Malaria – a neglected disease? Parasitology 104, S53–S69.CrossRefGoogle ScholarPubMed
Nicol, W. D. (1927). The care and management of induced malaria. Journal of Mental Science 73, 209–17.CrossRefGoogle Scholar
Polayes, S. H. & Derby, I. M. (1934). Blood groups and therapeutic malaria. Journal of the American Medical Association 102, 1126–8.CrossRefGoogle Scholar
Ponnundurai, T., Lensen, A. H. W., Van Gemert, G. J. A., Bolmer, M. G. & Meuwissen, J. H. E. T. (1991). Feeding behaviour and sporozoite ejection by infected Anopheles stephensi. Transactions of the Royal Society of Tropical Medicine and Hygiene 85, 175–80.CrossRefGoogle Scholar
Rosenberg, R., Wirtz, R. A., Schneider, I. & Buge, R. (1990). An estimation of the number of malaria sporozoites ejected by a feeding mosquito. Transactions of the Royal Society of Tropical Medicine and Hygiene 84, 209–12.CrossRefGoogle ScholarPubMed
Roy, D. N. (1938). A note on Shute's technique of enumerating sporozoites in an emulsion of salivary glands. Journal of the Malaria Institute of India 1, 335–7.Google Scholar
Shute, P. G. (1937). A technique for the inoculation of known numbers of sporozoites as an aid to malaria research. Annals of Tropical Medicine and Parasitology 31, 85–7.CrossRefGoogle Scholar
Shute, P. G. (1945). An investigation into the number of sporozoites found in salivary glands of Anopheles mosquitoes. Transactions of the Royal Society of Tropical Medicine and Hygiene 36, 493–8.CrossRefGoogle Scholar
Shute, P. G. (1946). The maintenance of a strain of Plasmodium vivax through man and mosquito over a period of 21 years. Monthly Bulletin of Ministry of Health and Emergency Public Health Laboratory Services, 5 110–12.Google Scholar
Shute, P. G. (1951). Mosquito infection in artificially induced malaria. British Medical Bulletin 8, 56–63.CrossRefGoogle ScholarPubMed
Shute, P. G. (1952). Malaria fever therapy. Lancet 2, 333–6.CrossRefGoogle Scholar
Snow, R. W., Lindsay, S. W., Hayes, R. J. & Greenwood, B. M. (1988). Permethrin-treated bed nets (mosquito nets) prevent malaria in Gambian children. Transactions of the Royal Society of Tropical Medicine and Hygiene 82, 838–42.CrossRefGoogle ScholarPubMed
Warrell, D. A., Molyneux, M. E. & Beales, P. F. (1990). Severe and complicated malaria. Transactions of the Royal Society of Tropical Medicine and Hygiene 84 (Suppl. 2), 1–65.Google Scholar
Whelen, M. & Shute, P. G. (1943). Thio-Bismol in therapeutic malaria. Journal of Tropical Medicine and Hygiene 46, 1–5.Google Scholar
Whorton, C. M., Yount, E., Jones, R., Alving, A. S., Pullman, T. N., Craige, B. & Eichelberger, L. (1947). The Chesson strain of Plasmodium vivax malaria III. Clinical aspects. Journal of Infectious Diseases 80, 237–49.CrossRefGoogle Scholar