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Moderate to heavy infections of Trichuris trichiura affect cognitive function in Jamaican school children

Published online by Cambridge University Press:  06 April 2009

C. Nokes
Affiliation:
Wellcome Trust Research Centre for Parasitic Infections, Department of Biology, Imperial College, Prince Consort Road, London SW7 2BB
S. M. Grantham-McGregor
Affiliation:
Tropical Metabolism Research Unit, University of the West Indies, Kingston, Jamaica, West Indies
A. W. Sawyer
Affiliation:
Wellcome Trust Research Centre for Parasitic Infections, Department of Biology, Imperial College, Prince Consort Road, London SW7 2BB
E. S. Cooper
Affiliation:
Wellcome Trust Research Centre for Parasitic Infections, Department of Biology, Imperial College, Prince Consort Road, London SW7 2BB
B. A. Robinson
Affiliation:
Mandeville Public General Hospital, Mandeville, Manchester, Jamaica, West Indies
D. A. P. Bundy
Affiliation:
Mandeville Public General Hospital, Mandeville, Manchester, Jamaica, West Indies

Extract

A double-blind placebo trial was conducted to determine the effect of moderate to high loads of Trichuris trichiura (whipworm) infection on the cognitive functions of 159 school children (age 9–12 years) in Jamaica. Infected children were randomly assigned to Treatment or Placebo groups. A third group of randomly selected uninfected children were assigned to a Control for comparative purposes. The improvement in cognitive function was evaluated using a stepwise multiple linear regression, designed to control for any confounding variables. The expulsion of worms led to a significant improvement in tests of auditory short-term memory (P < 0.02; P < 0.01), and a highly significant improvement in the scanning and retrieval of long-term memory (P < 0.001). After 9 weeks, treated children were no longer significantly different from an uninfected Control group in these three tests of cognitive function. The removal of T. trichiura was more important than Ascaris lumbricoides in determining this improvement. The results suggest that whipworm infection has an adverse effect on certain cognitive functions which is reversible by therapy.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1992

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References

Bowerman, B. L. & O'Connell, R. T. (1990). Linear Statistical Models: an Applied Approach, 2nd Edn.The Duxbury Advanced Series in Statistics and Decision Sciences: PWS-Kent.Google Scholar
Bundy, D. A. P. (1986). Epidemiological aspects of Trichuris and trichuriasis in Caribbean communities. Transactions of the Royal Society of Tropical Medicine and Hygiene 80, 706–18.CrossRefGoogle ScholarPubMed
Bundy, D. A. P., Foreman, J. D. M. & Golden, M. H. N. (1985). Sodium azide preservation of faecal specimens for Kato analysis. Parasitology 90, 463–9.CrossRefGoogle ScholarPubMed
Bundy, D. A. P., Wong, M. S. & Horton, J. (1990). Control of geohelminths by delivery of targeted chemotherapy through schools. Transactions of the Royal Society of Medicine and Hygiene 84, 115–20.CrossRefGoogle ScholarPubMed
Clarke, N. M. A., Grantham-McGregor, S. M. & Powell, C. (1991). Nutrition and health predictors of school failure in Jamaican children. Ecology of Food and Nutrition 26, 111.CrossRefGoogle Scholar
Cooper, E. S. & Bundy, D. A. P. (1987). Trichuriasis. In Baillière's Clinical Tropical Medicine and Communicable Diseases, Vol. 2 (ed. Pawlowski, Z. S.), pp. 629–43. London: Baillière Tindall Limited.Google Scholar
Cooper, E. S., Bundy, D. A. P., Macdonald, T. T. & Golden, M. H. N. (1990). Growth suppression in the Trichuris dysentery syndrome. European Journal of Clinical Nutrition 44, 138–47.Google ScholarPubMed
De Carneri, I. (1968). Indagine elmintologica quantitative nella popolazione scolare di 21 centri rurali della provincia di pavia con riferimenti alla situazione socioeconomica e igienica familiare e al rendimento scolastico. Nuovi Annali d'igiene e Microbiologia 19, 124.Google Scholar
Eysenck, M. W. (1986). Arousal, learning and memory. Psychological Bulletin 83, 389404.CrossRefGoogle Scholar
Gilman, R. H., Chong, Y. H., Davis, C., Greenberg, B., Virik, H. K. & Dixon, H. B. (1983). The adverse consequences of heavy Trichuris infection. Transactions of the Royal Society of Tropical Medicine and Hygiene 77, 432–8.CrossRefGoogle ScholarPubMed
Grantham-McGregor, S. M. (1990). Malnutrition, mental function and development. In The Malnourished Child, Nestlé Nutrition Workshop Series, Vol. 19 (ed. Suskind, R. M. & Lewinter-Suskind, L.), pp. 197212. New York: Raven Press.Google Scholar
Hall, A. (1981). Quantitative variability of nematode egg counts in faeces: a study among rural Kenyans. Transactions of the Royal Society of Tropical Medicine and Hygiene 75, 682–7.CrossRefGoogle ScholarPubMed
Halloran, M. E., Bundy, D. A. P. & Pollitt, E. (1989). Infectious disease and the Unesco basic education initiative. Parasitology Today 5, 359–62.CrossRefGoogle ScholarPubMed
Holland, C. (1987). Neglected infections – trichuriasis and strongyloidiasis. In Impact of Helminth Infections on Human Nutrition (ed. Stephenson, L. S.), pp. 161201. London: Taylor & Francis.Google Scholar
Jolliffe, J. T. (1986). Principal Components as a small number of interpretable variables: some examples. In Principal Component Analysis, (ed. Jolliffe, J. T.), pp. 50–8. Springer Series in Statistics: Berlin: Springer-Verlag.CrossRefGoogle Scholar
Jordon, P. & Randall, K. (1962). Bilharziasis in Tanganyika: observations on its effects and the effects of treatment in school children. Journal of Tropical Medicine and Hygiene 65, 17.Google Scholar
Kagan, J., Rosman, B., Day, D., Albert, J. & Phillips, W. (1964). Information processing in the child: significance of analytic and reflective attitudes. Psychological Monographs 78, 578615.CrossRefGoogle Scholar
Kaufman, A. (1979). Intelligence Testing with the WISC-R. New York: John Wiley and Sons.Google Scholar
Martin, L. K. & Beaver, P. C. (1968). Evaluation of Kato Thick Smear Technique for quantitative diagnosis of helminth infections. American Journal of Tropical Medicine and Hygiene 17, 382–91.CrossRefGoogle ScholarPubMed
Nokes, C., Cooper, E. S., Robinson, B. A. & Bundy, D. A. P. (1991). Geohelminth infection and academic assessment in Jamaican children. Transactions of the Royal Society of Tropical Medicine and Hygiene 85, 272–3.CrossRefGoogle ScholarPubMed
Pollitt, E. (1990). Malnutrition and Infection in the Classroom. Paris: Unesco Publication.Google Scholar
Raven, J. C. (1956). Coloured Progressive Matrices. London: H. K. Lewis & Co.Google Scholar
Semel, E. & Wiig, E. (1980). Clinical Evaluation of Language Functions. Columbus, OH: Charles Merrill.Google Scholar
Simeon, D. T. & Grantham-McGregor, S. M. (1989). Effects of missing breakfast of the cognitive functions of school children on differing nutritional status. American Journal of Clinical Nutrition 49, 646–53.CrossRefGoogle ScholarPubMed
Soewondo, S., Husaini, M. & Pollitt, E. (1989). Effects of iron deficiency on attention and learning processes in preschool children: Bandung, Indonesia. American Journal of Clinical Nutrition 50 (Suppl.), S667–S673.CrossRefGoogle ScholarPubMed
Stephenson, L. S., Latham, M. C. & Oduori, M. L. (1980). Costs, prevalence and approaches for control of Ascaris infection in Kenya. Journal of Tropical Paediatrics 26, 246–62.CrossRefGoogle Scholar
Stiles, C. W. (1915). The school grades attained by 2166 white school children (1062 boys, 1104 girls) in the city of X, classified by age, sanitation and intestinal parasites. U.S. Public Health System Report, No. 121.Google Scholar
Strong, K. K. (1916). Effects of Hookworm Disease in the Mental and Physical Development of Children. International Health Commission, Publication No. 3. New York: The Rockefeller Foundation.Google Scholar
United States Department Of Health Education and Welfare Public Health Services, Health Resources Administration(1976). NCHS Growth Charts. Rockville, MD: Health Resources Administration.Google Scholar
Waite, J. H. & Neilson, L. (1919). A study of the effects of hookworm infection upon the mental development of North Queensland school children. The Medical Journal of Australia 1, 117.CrossRefGoogle Scholar
Walker, A. R. P., Walker, B. F. & Richardson, B. D. (1970). Studies on schistosomiasis in a South African Bantu schoolchild population. American Journal of Tropical Medicine and Hygiene 19, 792814.CrossRefGoogle Scholar
Wechsler, D. (1974). Wechsler Intelligence Scale for Children – Revised. New York: The Psychological Corporation.Google Scholar
World Health Organization (1987). Prevention and control of intestinal parasitic infections. World Health Organization Technical Report Series, No. 749. Geneva: WHO.Google Scholar