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The influence of sampling effort and the performance of the Kato-Katz technique in diagnosing Schistosoma mansoni and hookworm co-infections in rural Côte d'Ivoire

  • M. BOOTH (a1), P. VOUNATSOU (a2), E. K. N'GORAN (a3), M. TANNER (a2) and J. UTZINGER (a4)...

The Kato-Katz method is widely used for diagnosing helminth infections in epidemiological surveys, but is known to have a low sensitivity. In the case of Schistosoma mansoni, statistical methods have been developed to compensate for the poor sensitivity, but the same is not true of any other helminth parasite, or infections with multiple-helminth species. We screened 101 schoolchildren from a rural area of Côte d'Ivoire over 5 consecutive days and made 5 Kato-Katz readings from each stool specimen. We estimated single and dual-species infections with S. mansoni and hookworm based on raw egg count data and after developing a latent-class model. The cumulative prevalence of co-infections was estimated at 9·9% after reading slides on the first day, and 57·0% after reading all 25 slides per person. The latent class model yielded a co-infection prevalence estimate of 79·6%, with marginal prevalence estimates for hookworm and S. mansoni infections of 83·9% and 91·6% respectively. The sensitivities of a single Kato-Katz thick smear for detection of S. mansoni alone, hookworms alone, or S. mansoni plus hookworms were 22·4%, 8·0% and 17·7%, respectively. In the current setting this could be attributable to low infection intensities of both parasites, combined with intra-specimen and day-to-day variation in egg output. If confirmed in other settings, these findings have implications for estimating the prevalence of multiple species helminth infections, and hence the design and implementation of efficacious and cost-effective control programmes.

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Department of Pathology, University of Cambridge, Tennis Court Road, Cambridge CB2 1QP, UK. Tel: +44 (0)1223 333338. Fax: +44 (0)1223 333741. E-mail:
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ALLEN, A. V. & RIDLEY, D. S. ( 1970). Further observations on the formol-ether concentration technique for faecal parasites. Journal of Clinical Pathology23, 545546.

BOOTH, M. & BUNDY, D. A. ( 1995). Estimating the number of multiple-species geohelminth infections in human communities. Parasitology111, 645653.

BROOKER, S., BOOTH, M. & GUYATT, H. ( 1999). Comparisons of schistosome and geohelminth infection prevalences in school-aged children from selected areas of Africa: implications for rapid assessment and combined control. Transactions of the Royal Society of Tropical Medicine and Hygiene93, 125126.

CARABIN, H., GUYATT, H. & ENGELS, D. ( 2000). A comparative analysis of the cost-effectiveness of treatment based on parasitological and symptomatic screening for Schistosoma mansoni in Burundi. Tropical Medicine and International Health5, 192202.

DE VLAS, S. J., ENGELS, D., RABELLO, A. L., OOSTBURG, B. F., VAN LIESHOUT, L., POLDERMAN, A. M., VAN OORTMARSSEN, G. J., HABBEMA, J. D. & GRYSEELS, B. ( 1997). Validation of a chart to estimate true Schistosoma mansoni prevalences from simple egg counts. Parasitology114, 113121.

DE VLAS, S. J., GRYSEELS, B., VAN OORTMARSSEN, G. J., POLDERMAN, A. M. & HABBEMA, J. D. ( 1992). A model for variations in single and repeated egg counts in Schistosoma mansoni infections. Parasitology104, 451460.

ENGELS, D., NAHIMANA, S. & GRYSEELS, B. ( 1996). Comparison of the direct faecal smear and two thick smear techniques for the diagnosis of intestinal parasitic infections. Transactions of the Royal Society of Tropical Medicine and Hygiene90, 523525.

EZZATI, M., LOPEZ, A. D., RODGERS, A., VANDER HOORN, S., MURRAY, C. J. L. & COMPARATIVE RISK ASSESSMENT COLLABORATING GROUP ( 2002). Selected major risk factors and global and regional burden of disease. Lancet360, 13471360.

GOODMAN, L. A. ( 1974). Exploratory latent structure analysis using both identifiable and unidentifiable models. Biometrika61, 215231.

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 Hygiene75, 682687.

HAMILTON, J. V., KLINKERT, M. & DOENHOFF, M. J. ( 1998). Diagnosis of schistosomiasis: antibody detection, with notes on parasitological and antigen detection methods. Parasitology117 (Suppl.), S41S57.

HOWARD, S. C., DONNELLY, C. A. & CHAN, M. S. ( 2001). Methods for estimation of associations between multiple species parasite infections. Parasitology122, 233251.

KEISER, J., N'GORAN, E. K., SINGER, B. H., LENGELER, C., TANNER, M. & UTZINGER, J. (2002a). Association between Schistosoma mansoni and hookworm infections among schoolchildren in Côte d'Ivoire. Acta Tropica84, 3141.

KEISER, J., N'GORAN, E. K., TRAORÉ, M., LOHOURIGNON, K. L., SINGER, B. H., LENGELER, C., TANNER, M. & UTZINGER, J. ( 2002b). Polyparasitism with Schistosoma mansoni, geohelminths, and intestinal protozoa in rural Côte d'Ivoire. Journal of Parasitology88, 461466.

MURRAY, C. J. L. & LOPEZ, A. D. ( 1997). Global mortality, disability, and the contribution of risk factors: Global Burden of Disease Study. Lancet349, 14361442.

POLMAN, K., DE VLAS, S. J., VAN LIESHOUT, L., DEELDER, A. M. & GRYSEELS, B. ( 2001). Evaluation of density-dependent fecundity in human Schistosoma mansoni infections by relating egg counts to circulating antigens through Deming regression. Parasitology122, 161167.

UTZINGER, J., BOOTH, M., N'GORAN, E. K., MÜLLER, I., TANNER, M. & LENGELER, C. ( 2001). Relative contribution of day-to-day and intra-specimen variation in faecal egg counts of Schistosoma mansoni before and after treatment with praziquantel. Parasitology122, 537544.

UTZINGER, J., VOUNATSOU, P., N'GORAN, E. K., TANNER, M. & BOOTH, M. ( 2002). Reduction in the prevalence and intensity of hookworm infections after praziquantel treatment for schistosomiasis infection. International Journal for Parasitology32, 759765.

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