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The current status of onchocerciasis in the forest/savanna transition zone of Côte d'Ivoire

Published online by Cambridge University Press:  16 April 2004

A. G. ADJAMI
Affiliation:
Multi Disease Surveillance Centre, World Health Organization, B.P. 549, Ouagadougou, Burkina Faso
L. TOÉ
Affiliation:
Multi Disease Surveillance Centre, World Health Organization, B.P. 549, Ouagadougou, Burkina Faso
Y. BISSAN
Affiliation:
Multi Disease Surveillance Centre, World Health Organization, B.P. 549, Ouagadougou, Burkina Faso
S. BUGRI
Affiliation:
Multi Disease Surveillance Centre, World Health Organization, B.P. 549, Ouagadougou, Burkina Faso
L. YAMÉOGO
Affiliation:
African Programme for Onchocerciasis Control, World Health Organization, B.P. 549, Ouagadougou, Burkina Faso
M. KONE
Affiliation:
Centre Pierre Richet, B.P. 1500, Bouake 01, Côte d'Ivoire
C. R. KATHOLI
Affiliation:
Department of Biostatistics, University of Alabama at Birmingham, 1530 3rd Avenue South, Birmingham AL 35294, USA
T. R. UNNASCH
Affiliation:
Division of Geographic Medicine, University of Alabama at Birmingham, 1530 3rd Avenue South, Birmingham AL 35294, USA

Abstract

Onchocerca volvulus exists in at least two strains in West Africa, while its black-fly vectors consist of sibling species, dwelling in the savanna and forest/transition zones. In transition and degraded forest zones both parasite strains and different sibling species of the vector can be sympatric. The strain of parasite in infected humans and in vector black-flies was determined in two bioclimes along the Bandama river of Côte d'Ivoire. The upper Bandama is located in the savanna bioclime while the Middle Bandama is located in a degraded forest zone. At both sites, savanna-dwelling sibling species of the Simulium damnosum sensu lato species complex predominated. The severe-strain of O. volvulus was the predominant strain at both sites. However, severe-strain parasites represented a significantly larger proportion of those found in the vector population than in the human population in the degraded forest of the Middle Bandama. These data suggest that in degraded forest areas recently invaded by savanna-dwelling species of S. damnosum s.l. transmission of the severe-strain of the parasite might be more efficient than transmission of the mild-strain.

Type
Research Article
Copyright
© 2004 Cambridge University Press

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References

REFERENCES

BISSAN, Y., HOUGARD, J. M., DOUCOURE, K., AKPOBOUA, A., BACK, C., POUDIOUGO, P., SIB, A. P., COULIBALY, Y., GUILLET, P. & SESAY, I. (1995). Drastic reduction of populations of Simulium sirbanum (Diptera: Simuliidae) in central Sierra Leone after 5 years of larviciding operations by the Onchocerciasis Control Programme. Annals of Tropical Medicine and Parasitology 89, 6372.CrossRefGoogle Scholar
BOATIN, B., MOLYNEUX, D. H., HOUGARD, J. M., CHRISTENSEN, O. W., ALLEY, E. S., YAMEOGO, L., SEKETELI, A. & DADZIE, K. Y. (1997). Patterns of epidemiology and control of onchocerciasis in West Africa. Journal of Helminthology 71, 91101.CrossRefGoogle Scholar
DADZIE, K. Y., REMME, J., ROLLAND, A. & THYLEFORS, B. (1989). Ocular onchocerciasis and intensity of infection in the community. II. West African rainforest foci of the vector Simulium yahense. Tropical Medicine and Parasitology 40, 348354.Google Scholar
DAVIES, J. B., SEKETELI, A., WALSH, J. F., BARRO, T. & SAWADOGO, R. (1981). Studies on biting Simulium damnosum s.l. at a breeding site in the Onchocerciasis Control Programme area during and after an interruption of insecticidal treatments. Tropical Medicine and Parasitology 32, 1724.Google Scholar
DESOLE, G., REMME, J. & DADZIE, K. Y. (1990). Epidemiological impact of vector control. I. Incidence and changes in prevalence and intensity of Onchocerca volvulus infection. Acta Leidensia 59, 119126.Google Scholar
DUKE, B. O. L., LEWIS, D. J. & MOORE, P. J. (1966). Onchocerca–Simulium complexes. I. Transmission of forest and Sudan-savannah strains of Onchocerca volvulus, from Cameroon, by Simulium damnosum from various West African bioclimatic zones. Annals of Tropical Medicine and Parasitology 60, 318336.Google Scholar
DUKE, B. O. L. (1981). Geographical aspects of onchocerciasis. Annales of the Belgian Society of Tropical Medicine 61, 179186.Google Scholar
ERTTMANN, K. D., UNNASCH, T. R., GREENE, B. M., ALBIEZ, E. J., BOATENG, J., DENKE, A. M., FERRARONI, J. J., KARAM, M., SCHULZ-KEY, H. & WILLIAMS, P. N. (1987). A DNA sequence specific for forest form Onchocerca volvulus. Nature, London 327, 415417.CrossRefGoogle Scholar
ERTTMANN, K. D., MEREDITH, S. E. O., GREENE, B. M. & UNNASCH, T. R. (1990). Isolation and characterization of form specific DNA sequences of Onchocerca volvulus. Acta Leidensia 59, 253260.Google Scholar
ETYA'ALE, D. (2002). Eliminating onchocerciasis as a public health problem: The beginning of the end. British Journal of Ophthalmology 86, 844846.CrossRefGoogle Scholar
GARMS, R. (1985). Morphological differentiation from Onchocerca volvulus of first stage larvae of an unknown filarial species commonly found in Simulium sanctipauli s.l. in Liberia. Tropical Medicine and Parasitology 36, 255256.Google Scholar
HOUGARD, J. M., ALLEY, E. S., YAMEOGO, L., DADZIE, K. Y. & BOATIN, B. A. (2001). Eliminating onchocerciasis after 14 years of vector control: A proved strategy. Journal of Infectious Diseases 184, 497503.CrossRefGoogle Scholar
McCALL, P. J., TOWNSON, H. & TREES, A. J. (1992). Morphometric differentiation of Onchocerca volvulus and O. ochengi infective larvae. Transactions of the Royal Society of Tropical Medicine and Hygiene 86, 6365.CrossRefGoogle Scholar
OMAR, M. S. & GARMS, R. (1981). Histochemical differentiation of filarial larvae found in Simulium damnosum s.l. in West Africa. Tropical Medicine and Parasitology 32, 259264.Google Scholar
PHILIPPON, B. (1976). Etude de la transmission d'Onchocerca volvulus (Leuckart, 1893) (Nematoda, Onchocercidae) par Simulium damnosum (Theobad, 1903) (Diptera, Simuliidae) en Afrique tropicale. Travaux et documents de l'ORSTOM, 1308.Google Scholar
PHILIPPON, B., REMME, J. H., WALSH, J. F., GUILLET, P. & ZERBO, D. G. (1990). Entomological results of vector control in the Onchocerciasis Control Programme. Acta Leidensia 59, 7994.Google Scholar
PHILIPPON, B. & SÉKÉTÉLI, A. (1998). The beginning of the OCP and the status of onchocerciasis in western Africa before control measures. Cahier Santé 8, 2731.Google Scholar
REMME, J., DADZIE, K. Y., ROLLAND, A. & THYLEFORS, B. (1989). Ocular onchocerciasis and intensity of infection in the community. I. West African savannah. Tropical Medicine and Parasitology 40, 340347.Google Scholar
SÉCHAN, Y. (1984). Développement d'onchocerques animales chez le vecteur de l'onchocercose humaine Simulium sirbanum (Vajime et Dunbar, 1975), en zone subsahélienne du Mali Afrique de l'ouest. Travaux et documents de l'ORSTOM 178, 234.Google Scholar
TOÈ, L., MERRIWEATHER, A. & UNNASCH, T. R. (1994). DNA probe based classification of Simulium damnosum s.l. borne and human derived filarial parasites in the Onchocerciasis Control Programme area. American Journal of Tropical Medicine and Hygiene 51, 676683.Google Scholar
TOÈ, L., BACK, C., ADJAMI, A. G., TANG, J. M. & UNNASCH, T. R. (1997 a). Onchocerca volvulus: Comparison of field collection methods for the preservation of parasite and vector samples for PCR analysis. Bulletin of the World Health Organization 75, 443447.Google Scholar
TOÈ, L., TANG, J., BACK, C., KATHOLI, C. R. & UNNASCH, T. R. (1997 b). Vector–Parasite transmission complexes for onchocerciasis in West Africa. The Lancet 349, 163166.Google Scholar
UNNASCH, T. R. & MEREDITH, S. E. O. (1996). The use of degenerate primers in conjunction with strain and species oligonucleotides to classify Onchocerca volvulus. In Species Diagnostic Protocols: PCR and other Nucleic Acid Methods ( ed. J. P. Clapp ), pp. 293303. Humana Press, Totowa, NJ, USA.
WALSH, J. F., MOLYNEUX, D. H. & BIRLEY, M. H. (1993). Deforestation: effects on vector-borne disease. Parasitology 106, S55S75.CrossRefGoogle Scholar
WILSON, M. D., POST, R. J. & GOMULSKI, L. M. (1993). Multivariate morphotaxonomy in the identification of adult females of the Simulium damnosum Theobald complex (Diptera: Simuliidae) in the Onchocerciasis Control Programme area of West Africa. Annals of Tropical Medicine and Parasitology 87, 6582.CrossRefGoogle Scholar
WILSON, M. D., CHEKE, R. A., FLASSE, S. P., GRIST, S., OSEI-ATEWENEBOANA, M. Y., TETTEH-KUMAH, A., FIASORGBOR, G. K., JOLLIFFE, F. R., BOAKYE, D. A., HOUGARD, J. M., YAMEOGO, L. & POST, R. J. (2002). Deforestation and the spatio-temporal distribution of savannah and forest members of the Simulium damnosum complex in southern Ghana and south-western Togo. Transactions of the Royal Society of Tropical Medicine and Hygiene 96, 632639.CrossRefGoogle Scholar
YAMÈOGO, L., TOÈ, L., HOUGARD, J.-M., BOATIN, B. A. & UNNASCH, T. R. (1999). Pool Screen PCR for estimating the prevalence of Onchocerca volvulus infection in Simulium damnosum sensu lato: Results of a field trial in an area subject to successful vector control. American Journal of Tropical Medicine and Hygiene 60, 124128.CrossRefGoogle Scholar
ZIMMERMAN, P. A., DADZIE, K. Y., DESOLE, G., REMME, J., ALLEY, E. S. & UNNASCH, T. R. (1992). Onchocerca volvulus DNA probe classification correlates with epidemiological patterns of blindness. Journal of Infectious Diseases 165, 964968.CrossRefGoogle Scholar
ZIMMERMAN, P. A., TOÈ, L. & UNNASCH, T. R. (1993). Design of Onchocerca DNA probes based upon analysis of a repeated sequence family. Molecular and Biochemical Parasitology 58, 259269.CrossRefGoogle Scholar