Entomological risk assessment of human onchocerciasis transmission around the Samendeni dam, Guiriko region of Burkina Faso
DOI:
https://doi.org/10.64707/revstss.v48i2.1977Abstract
Abstract:
Background: Onchocerciasis, or "river blindness," is a parasitic disease caused by the parasite Onchocerca volvulus, transmitted by repeated bites of blackflies of the Simulium damnosum complex. Dam construction is a risk factor for re-emergence due to the proliferation of breeding sites favorable to blackfly development. This study assessed the impact of the Samendeni dam on entomological indicators of onchocerciasis transmission. Methods: Blackflies were collected using the human landing catch method in October 2024 at four collection points located around the Samendeni dam. Blackflies captured were morphologically identified and then pooled into groups of 100 individuals for DNA extraction, followed by Ov-150 qPCR analysis. Daily biting rates and infectivity rates were determined to assess onchocerciasis transmission.
Results: A total of 4,835 female blackflies of the S. damnosum complex were collected. The average daily biting rate was 173 bites/person/day, significantly higher than the threshold of 30 bites/person/day, thus indicating an important nuisance. Molecular analyses revealed the absence of the O. volvulus parasite in the collected blackflies. Infectivity rates were zero, revealing an interruption of human onchocerciasis transmission in the village of Samendeni. Conclusion: Our results demonstrate the absence of onchocerciasis transmission around the Samendeni dam, but the high biting rates constitute a risk in case of reintroduction of the parasite responsible for onchocerciasis. Entomological surveillance of the disease must be maintained to prevent any re-emergence.
References
Adewale B, Mafe M, Oyerinde J: Infectivity and transmission dynamics of Simulium damnosum s.l. around Owena dam (Ondo State). West Afr J Med. 1999, 18: 257-260.
Doherty, M., Grant, J. R., Pilotte, N., Bennuru, S., Fischer, K., Fischer, P. U., ... & Williams, S. A. (2023). Optimized strategy for real-time qPCR detection of Onchocerca volvulus DNA in pooled Simulium sp. blackfly vectors. PLoS neglected tropical diseases, 17(12), e0011815. DOI: https://doi.org/10.1371/journal.pntd.0011815
Enyong, P., Traoré, S., Louango, E., Fobi, G., Noma, M., Yaméogo, L., ... & Sékétéli, A. (2006). Programme africain de lutte contre l’onchocercose (APOC): transmission d’Onchocerca volvulus par Simulium damnosum S. l. dans deux régions de la République Centrafricaine. Parasite, 13(1), 35-44. DOI: https://doi.org/10.1051/parasite/2006131035
Garms, R., 1981. The reinvasion of the onchocerciasis control programme area in the Volta River Basin by Simulium damnosum s.l., the involvement of the different cytospecies and epidemiological implications. Ann. Soc. Belg. Med. Trop. 61, 193–198.
Koala, L., Nikièma, A. S., Ouedraogo, M., Compaoré, J., Bougouma, C., Sanon, K., ... & Dabire, R. K. (2025). Entomological surveillance of onchocerciasis in Burkina Faso: Progress towards interrupting transmission in blackflies in the main river basins of the country. Current Research in Parasitology & Vector-Borne Diseases, 7, 100259. DOI: https://doi.org/10.1016/j.crpvbd.2025.100259
Koala, L., Tirados, I., Nikiema, A. S., Thomsen, E., McCall, P. J., & Dabire, R. K. (2022). Prospects for developing efficient targets for the xenomonitoring and control of Simulium damnosum sl, the major vectors of onchocerciasis in Africa. Medical and Veterinary Entomology, 36(3), 235-246. DOI: https://doi.org/10.1111/mve.12598
Koala, L., Nikiema, A., Post, R. J., Paré, A. B., Kafando, C. M., Drabo, F., & Traoré, S. (2017). Recrudescence of onchocerciasis in the Comoé valley in Southwest Burkina Faso. Acta Tropica, 166, 96-105. DOI: https://doi.org/10.1016/j.actatropica.2016.11.003
Koala, L., Nikièma, A. S., Paré, A. B., Drabo, F., Toé, L. D., Belem, A. M., ... & Dabiré, R. K. (2019). Entomological assessment of the transmission following recrudescence of onchocerciasis in the Comoé Valley, Burkina Faso. Parasites & Vectors, 12(1), 34. DOI: https://doi.org/10.1186/s13071-019-3290-5
Kuzoe F, Hagan K: The control of Simulium damnosum Theobald (Diptera, Simuliidae) in the region of the Volta Dam. Annals Trop Med Parasit. 1967, 61: 338-347. DOI: https://doi.org/10.1080/00034983.1967.11686496
Leuckart, W.G.F.R. 1893. « Disease of the skin in tropical climates. British Museum, 1: 88.
Myriam and Cécile. Extraction d’AND au CTAB sur moustique entier. 2003. Myriam et Cécile. (2003). Protocoles de biologie moléculaire en usage au lin. Institut de recherche pour le développement (IRD).
Nikièma, A. S., Koala, L., Post, R. J., Paré, A. B., Kafando, C. M., Drabo, F., ... & Traoré, S. (2018). Onchocerciasis prevalence, human migration and risks for onchocerciasis elimination in the Upper Mouhoun, Nakambé and Nazinon river basins in Burkina Faso. Acta tropica, 185, 176-182. DOI: https://doi.org/10.1016/j.actatropica.2018.05.013
Nikièma, A. S., Koala, L., Post, R. J., Kima, A., Compaoré, J., Kafando, C. M., ... & Dabiré, R. K. (2024). Progress towards elimination of onchocerciasis in the Region du Sud-Ouest of Burkina Faso which was previously subject to a recrudescence event after vector control. PLOS Neglected Tropical Diseases, 18(4), e0012118. DOI: https://doi.org/10.1371/journal.pntd.0012118
QUILLEVERE D. Contribution à l'étude des caractéristiques taxonomiques, bioécologiques et vectrices des membres du complexe Simulium damnosum présents en Côte d'Ivoire. Travaux et documents de l'ORSTOM, 1979, 109, 304 p.
WHO, 1985. Dix années de lutte contre l’onchocercose en Afrique de l’Ouest. (Document OCP/GVA/85.1A). World Health Organization, Geneva 113pp.
WHO, 2016. Guidelines for stopping mass drug administration and verifying elimination of human onchocerciasis: Criteria and procedures. World Health Organization, Geneva, Switzerland (No. WHO/HTM/NTD/PCT/2016.1). https://www.who.int/p ublications/i/item/9789241510011.
WHO, 2023. Entomological manual for onchocerciasis elimination programmes. World Health Organization, Geneva, Switzerland. https://iris.who.int/handle/10665/3716 88.
Zarroug, I.M., Elaagip, A.H., Abuelmaali, S.A. et al. The impact of Merowe Dam on Simulium hamedense vector of onchocerciasis in Abu Hamed focus - Northern Sudan. Parasites Vectors 7, 168 (2014). https://doi.org/10.1186/1756-3305-7-168 DOI: https://doi.org/10.1186/1756-3305-7-168
Downloads
Published
How to Cite
Issue
Section
License
Copyright (c) 2026 Sciences de la Santé
This work is licensed under a Creative Commons Attribution 4.0 International License.
