Volume 85, Issue 6
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645



We studied onchocerciasis transmission and impact on ocular morbidity in three health districts in North Region, Cameroon, where annual mass ivermectin treatment has been provided for 12–17 years. The studies, which took place from 2008 to 2010, consisted of skin snips for microfilariae (mf), palpation examinations for nodules, slit lamp examinations for mf in the eye, and vector dissections for larval infection rates. Adults had mf and nodule rates of 4.8% and 13.5%, respectively, and 5.5% had mf in the anterior chamber of the eye. Strong evidence of ongoing transmission was found in one health district, where despite 17 years of annual treatments, the annual transmission potential was 543 L3/person per year; additionally, children under 10 years of age had a 2.6% mf prevalence. Halting ivermectin treatments in North Cameroon now might risk recrudescence of transmission and ocular disease.


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  1. Bottomley C, Isham V, Collins RC, Basáñez MG, , 2008. Rates of microfilarial production by Onchocerca volvulus are not cumulatively reduced by multiple ivermectin treatments. Parasitology 135: 15711581.[Crossref]
  2. Cupp EW, Cupp MS, , 2005. Short report: impact of ivermectin community-level treatments on elimination of adult Onchocerca volvulus when individuals receive multiple treatments per year. Am J Trop Med Hyg 73: 159161.
  3. Report WHO, , 2010. African Programme for Onchocerciasis Control—report of the sixth meeting of national task forces, October 2009. Wkly Epidemiol Rec 4: 2328.
  4. Katabarwa M, Eyamba A, Habomugisha P, Lakwo T, Ekobo S, Kamgno J, Kuete T, Ndyomugyenyi R, Onapa A, Salifou M, Ntep M, Richards FO, , 2008. After a decade of annual dose mass ivermectin treatment in Cameroon and Uganda, onchocerciasis transmission continues. Trop Med Int Health 13: 11961203.[Crossref]
  5. Boatin BA, Hougard JM, Alley ES, Akpoboua LK, Yaméogo L, Dembélé N, Sékétéli A, Dadzie KY, , 1998. The impact of Mectizan on the transmission of onchocerciasis. Ann Trop Med Parasitol 92: S46S60.
  6. Richards F, Hopkins D, Cupp E, , 2000. Programmatic goals and approaches to onchocerciasis. Lancet 355: 16631664.[Crossref]
  7. Winnen M, Plaisier AP, Alley ES, Nagelkerke NJ, van Oortmarssen G, Boatin BA, Habbema JD, , 2002. Can ivermectin mass treatments eliminate onchocerciasis in Africa? Bull World Health Organ 80: 384391.
  8. Borsboom GJ, Boatin BA, Nagelkerke NJ, Agoua H, Akpoboua KL, Alley EW, Bissan Y, Renz A, Yameogo L, Remme JH, Habbema JD, , 2003. Impact of ivermectin on onchocerciasis transmission: assessing the empirical evidence that repeated ivermectin mass treatments may lead to elimination/eradication in West Africa. Filaria J 2: 8.[Crossref]
  9. Ndyomugyenyi R, Tukesiga E, Büttner DW, Garms R, , 2004. The impact of ivermectin treatment alone and when in parallel with Simulium neavei elimination on onchocerciasis in Uganda. Trop Med Int Health 9: 882886.[Crossref]
  10. Diawara L, Traoré MO, Badji A, Bissan Y, Doumbia K, Goita SF, Konaté L, Mounkoro K, Sarr MD, Seck AF, Toé L, Tourée S, Remme JH, , 2009. Feasibility of onchocerciasis elimination with ivermectin treatment in endemic foci in Africa: first evidence from studies in Mali and Senegal. PLoS Negl Trop Dis 3: e497.[Crossref]
  11. Anderson J, Fuglsang H, Marshall TF, Radolowicz A, Vaughan JP, , 1978. Studies on onchocerciasis in the United Cameroon Republic. IV. A four-year follow-up of six rain-forest and six savanna villages. The incidence of ocular lesions. Trans R Soc Trop Med Hyg 72: 513515.[Crossref]
  12. Chippaux JP, Boussinesq M, Fobi G, Lafleur C, Audugé A, Banos MT, Ngosso A, Prod'hon J, , 1999. Effect of repeated ivermectin treatments on ocular onchocerciasis: evaluation after six to eight doses. Ophthalmic Epidemiol 6: 229246.[Crossref]
  13. Renz A, Wenk P, Anderson J, Fuglsang H, , 1987. Studies on the dynamics of transmission of onchocerciasis in a Sudan-savanna area of North Cameroon V. What is a tolerable level of annual transmission potential? Ann Trop Med Parasitol 81: 263274.[Crossref]
  14. Renz AHJ, , 1985. Studies on the dynamics of transmission of onchocerciasis in a Sudan–Savanna of North Cameroon areas. Dissertation, University of Tubingen, Tubingen, Germany.
  15. Katabarwa MN, Habomugisha P, Richards FO, Jr, 2002. Implementing community-directed treatment with ivermectin for the control of onchocerciasis in Uganda (1997–2000): an evaluation. Ann Trop Med Parasitol 96: 6173.[Crossref]
  16. Salant P, Dilman DA, , 1994. How to Conduct Your Own Survey. New York, NY: John Wiley & Sons, Inc.
  17. Albiez EJ, Buttner DW, Duke BO, , 1988. Diagnosis and extirpation of nodules in human onchocerciasis. Trop Med Parasitol 39 (Suppl 4): 331346.
  18. Ngoumou P, Walsh JF, Mace JM, , 1994. A rapid mapping technique for the prevalence and distribution of onchocerciasis: a Cameroon case study. Ann Trop Med Parasitol 88: 463474.[Crossref]
  19. Katabarwa M, Onapa AW, Nakileza B, , 1999. Rapid epidemiological mapping of onchocerciasis in areas of Uganda where Simulium neavei sl. is the vector. East Afr Med J 76: 440446.
  20. Prost A, Prod'hon J, , 1978. Le diagnostique parasitologique de l'onchocercose. Revue critique des methods en usage. Medicine Tropicale 38: 519532.
  21. Schulz-Key H, , 1978. A simple technique to assess the total number of Onchocerca volvulus microfilariae in skin snips. Tropenmed Parasitol 29: 5154.
  22. Report of the World Health Organization, 1995. Onchocerciasis and its control. Report of a World Health Organization Expert Committee on Onchocerciasis Control. Technical Report Series 852. Geneva, Switzerland: World Health Organization.
  23. Report of the World Health Organization, 1991. Strategies for Ivermectin Distribution Through Primary Health Care System. Geneva, Switzerland: World Health Organization.
  24. Winthrop KL, Proaño R, Oliva O, Arana B, Mendoza C, Dominguez A, Amann J, Punkosdy G, Blanco C, Klein R, Sauerbrey M, Richards F, , 2006. The reliability of anterior segment lesions as indicators of onchocercal eye disease in Guatemala. Am J Trop Med Hyg 75: 10581062.
  25. Davies JB, , 1995. A rapid staining and clearing technique for detecting filarial larvae in alcohol-preserved vectors. Trans R Soc Trop Med Hyg 89: 280.[Crossref]
  26. Walsh JF, Davies JB, Le Berre R, Grams R, , 1978. Standardization of criteria for assessing the effect of Simulium control in onchocerciasis control programmes. Trans R Soc Trop Med Hyg 72: 675676.[Crossref]
  27. Gardon J, Boussinesq M, Kamgno J, Gardon-Wendel N, Demanga-Ngangue Duke BO, , 2002. Effects of standard and high doses of ivermectin on adult worms of Onchocerca volvulus: a randomised controlled trial. Lancet 360: 203210.[Crossref]
  28. Boussinesq M, Prod'hon J, Chippaux JP, , 1997. Onchocerca volvulus: striking decrease in transmission in the Vina valley (Cameroon) after eight annual large scale ivermectin treatments. Trans R Soc Trop Med Hyg 91: 8286.[Crossref]
  29. Lindblade KA, Arana B, Zea-Flores G, Rizzo N, Porter CH, Dominguez A, Cruz-Ortiz N, Unnasch TR, Punkosdy GA, Richards J, Sauerbrey M, Castro J, Catú E, Oliva O, Richards FO, Jr, 2007. Elimination of Onchocercia volvulus transmission in the Santa Rosa focus of Guatemala. Am J Trop Med Hyg 77: 334341.
  30. Report of the World Healh Organization, (2001). Certification of elimination of human onchocerciasis: criteria and procedures. Criteria for Certification of Interruption of Transmission/Elimination of Human Onchocerciasis. Geneva, Switzerland: World Health Organization.
  31. Osei-Atweneboana MY, Eng JK, Boakye DA, Gyapong JO, Prichard RK, (2007). Prevalence and intensity of Onchocerca volvulus infection and efficacy of ivermectin in endemic communities in Ghana: a two-phase epidemiological study. Lancet 369: 20212029.[Crossref]
  32. Ndyomugyenyi R, Lakwo T, Habomugisha P, Male B, , 2007. Progress towards the elimination of onchocerciasis as a public-health problem in Uganda: opportunities, challenges and the way forward. Ann Trop Med Parasitol 101: 323333.[Crossref]
  33. Gonzalez RJ, Cruz-Ortiz N, Rizzo N, Richards J, Zea-Flores G, Domínguez A, Sauerbrey M, Catú E, Oliva O, Richards FO, Lindblade KA, , 2009. Successful interruption of transmission of Onchocerca volvulus in the Escuintla-Guatemala focus, Guatemala. PLoS Negl Trop Dis 3: e404.[Crossref]
  34. Katabarwa MN, Eyamba A, Chouaibou M, Enyong P, Kuété T, Yaya S, Yougouda A, Baldiagaï J, Madi K, Andze GO, Richards F, , 2010. Does onchocerciasis transmission take place in hypoendemic areas? A study from the North Region of Cameroon. Trop Med Int Health 15: 645652.[Crossref]
  35. Seidenfaden R, Fischer A, Bonow I, Ekale D, Tanya V, Renz A, , 2001. Combined benefits of annual mass treatment with ivermectin and cattle zooprophylaxis on the severity of human onchocerciasis in northern Cameroon. Trop Med Int Health 9: 715725.[Crossref]
  36. Duke BO, Anderson J, Fuglsang H, , 1975. The Onchocerca volvulus transmission potentials and associated patterns of onchocerciasis at four Cameroon Sudan-savanna villages. Tropenmed Parasitol 26: 143154.
  37. Amazigo UV, Brieger WR, Katabarwa M, Akogun O, Ntep M, Boatin B, N'doyo J, Noma N, Seketeli A, , 2002. The challenges of community-directed treatment with ivermectin (CDTI) within the African Programme for Onchocerciasis Control (APOC). Ann Trop Med Parasitol 96: S75S92.[Crossref]
  38. Hopkins DR, Richards FO, Katabarwa M, , 2005. Whither onchocerciasis control in Africa. Am J Trop Med Hyg 72: 12.
  39. Rakers LJ, Emukah E, Onyenama J, Amah G, Ukairo N, Enyinnaya U, Miri E, Richards F, , 2009. Sustainability of ivermectin distribution programmes. Lance 374: 785786.[Crossref]

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  • Received : 25 May 2011
  • Accepted : 02 Aug 2011

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