1921
Volume 75, Issue 5
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645

Abstract

There is considerable host heterogeneity in exposure to onchocerciasis. We incorporate this heterogeneity into a model of onchocerciasis transmission that we use to evaluate intervention strategies targeting specific portions of the human population for treatment with ivermectin. Our model predicts that targeted allocation of ivermectin in a highly heterogeneous population will reduce the public health burden of onchocerciasis using 20–25% of the doses of untargeted allocation. Targeted allocation therefore poses significantly lower risk of adverse effects, while potentially delaying the emergence and spread of ivermectin resistance, relative to untargeted allocation.

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2006-11-01
2017-09-19
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References

  1. Kale OO, 1998. Onchocerciasis: the burden of disease. Ann Trop Med Parasitol 92 : S101–S115.
  2. Molyneux DH, Bradley M, Hoerauf A, Kyelem D, Taylor MJ, 2003. Mass drug treatment for lymphatic filariasis and onchocerciasis. Trends Parasitol 19 : 516–522.
  3. Waters HR, Rehwinkel JA, Burnham G, 2004. Economic evaluation of Mectizan distribution. Trop Med Int Health 9 : A16–A25.
  4. Aziz MA, Diallo S, Diop IM, Lariviere M, Porta M, 1982. Efficacy and tolerance of ivermectin in human onchocerciasis. Lancet 2 : 171–173.
  5. Cupp EW, Bernardo MJ, Kiszewski AE, Collins RC, Taylor HR, Aziz MA, Greene BM, 1986. The effects of ivermectin on transmission of Onchocerca volvulus. Science 231 : 740–742.
  6. Taylor MJ, Pacque M, Munoz B, Greene BM, 1990. Impact of mass treatment of onchocerciasis with ivermectin on the transmission of infection. Science 250 : 116–118.
  7. Collins K, 2004. Profitable Gifts: a history of the Merck Mectizan® donation program and its implications for international health. Perspect Biol Med 47 : 100–109.
  8. Plaisier AP, Alley ES, Boatin BA, Van Oortmarssen GJ, Remme H, De Vlas SJ, Bonneux L, Habbema JD, 1995. Irreversible effects of ivermectin on adult parasites in onchocerciasis patients in the Onchocerciasis Control Programme in West Africa. J Infect Dis 172 : 204–210.
  9. Boatin BA, Hougard JM, Alley ES, Akpoboua LK, Yameogo L, Dembele N, Seketeli A, Dadzie KY, 1998. The impact of Mectizan on the transmission of onchocerciasis. Ann Trop Med Parasitol 92 : S46–S60.
  10. Dadzie Y, Neira M, Hopkins D, 2003. Final report of the Conference on the eradicability of Onchocerciasis. Filaria J 2 : 2.
  11. Habbema JDF, Alley ES, Plaisier AP, Van Oortmarssen GJ, Remme JHF, 1992. Epidemiological modelling for onchocerciasis control. Parasitol Today 8 : 99–103.
  12. Duke BO, Moore PJ, 1968. The contributions of different age groups to the transmission of Onchocerciasis in a Cameroon forest village. Trans R Soc Trop Med Hyg 62 : 22–28.
  13. Boussinesq M, Hougard J-M, 1998. La lutte contre l’onchocercose en Afrique: aspects actuels. Med Trop (Mars) 58 : 285–296.
  14. 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.
  15. Nutman TB, 2002. Future directions for vaccine-related onchocerciasis research. Trends Parasitol 18 : 237–239.
  16. Soboslay PT, Geiger SM, Weiss N, Banla M, Lu der CG, Dreweck CM, Batchassi E, Boatin BA, Stadler A, Schulz-Key H, 1997. The diverse expression of immunity in humans at distinct states of Onchocerca volvulus infection. Immunology 90 : 592–599.
  17. Galvani AP, 2005. Age-dependent epidemiological patterns and strain diversity in helminth parasites. J Parasitol 91 : 24–30.
  18. Boussinesq M, Gardon J, Gardon-Wendel N, Kamgno J, Ngoumou P, Chippaux JP, 1998. Three probable cases of Loa loa encephalopathy following ivermectin treatment for onchocerciasis. Am J Trop Med Hyg 58 : 461–469.
  19. Njongmeta LM, Nfon CK, Gilbert J, Makepeace BL, Tanya VN, Trees AJ, 2004. Cattle protected from onchocerciasis by ivermectin are highly susceptible to infection after drug withdrawal. Int J Parasitol 34 : 1069–1074.
  20. Awadzi K, Boakye DA, Edwards G, Opoku NO, Attah SK, Osei-Atweneboana MY, Lazdins-Helds JK, Ardrey AE, Addy ET, Quartey BT, Ahmed K, Boatin BA, Soumbey-Alley EW, 2004. An investigation of persistent microfilaridermias despite multiple treatments with ivermectin, in two onchocerciasis-endemic foci in Ghana. Ann Trop Med Parasitol 98 : 231–249.
  21. Woolhouse MEJ, Dye C, Etard JF, Smith T, Charlwood JD, Garnett GP, Hagan P, Hii JLK, Ndhlovu PD, Quinnell RJ, Watts CH, Chandiwana SK, Anderson RM, 1997. Heterogeneities in the transmission of infectious agents: implications for the design of control programs. Proc Natl Acad Sci USA 94 : 338–342.
  22. Galvani AP, May RM, 2005. Epidemiology: dimensions of super-spreading. Nature 438 : 293–295.
  23. Bundy DA, 1990. Control of intestinal nematode infections by chemotherapy: mass treatment versus diagnostic screening. Trans R Soc Trop Med Hyg 84 : 622–625.
  24. Savioli L, Dixon H, Kisumku UM, Mott KE, 1989. Control of morbidity due to Schistosoma haematobium on Pemba island; selective population chemotherapy of schoolchildren with haematuria to identify high-risk localities. Trans R Soc Trop Med Hyg 83 : 805–810.
  25. Bundy DA, Wong MS, Lewis LL, Horton J, 1990. Control of geohelminths by delivery of targeted chemotherapy through schools. Trans R Soc Trop Med Hyg 84 : 115–120.
  26. Asaolu SO, Holland CV, Crompton DW, 1991. Community control of Ascaris lumbricoides in rural Oyo State, Nigeria: mass, targeted and selective treatment with levamisole. Parasitology 103 : 291–298.
  27. Anderson RM, May RM, 1991. Infectious Diseases of Humans: Dynamics and Control. New York: Oxford University Press.
  28. Vivas-Martinez S, Basanez MG, Botto C, Rojas S, Garcia M, Pacheco M, Curtis CF, 2000. Amazonian onchocerciasis: parasitological profiles by host-age, sex, and endemicity in southern Venezuela. Parasitology 121 : 513–525.
  29. Bockarie MJ, Davies JB, 1990. The transmission of onchocerciasis at a forest village in Sierra Leone. II. Man-fly contact, human activity and exposure to transmission. Ann Trop Med Parasitol 84 : 599–605.
  30. Filipe JA, Boussinesq M, Renz A, Collins RC, Vivas-Martinez S, Grillet ME, Little MP, Basanez MG, 2005. Human infection patterns and heterogeneous exposure in river blindness. Proc Natl Acad Sci USA 102 : 15265–15270.
  31. Galvani AP, 2003. Immunity, antigenic heterogeneity, and aggregation of helminth parasites. American Society of Parasitologists 89 : 232–241.
  32. Duerr HP, Dietz K, Schulz-Key H, Buttner DW, Eichner M, 2003. Density-dependent parasite establishment suggests infection-associated immunosuppression as an important mechanism for parasite density regulation in onchocerciasis. Trans R Soc Trop Med Hyg 97 : 242–250.
  33. Vivas-Martinez S, Basanez MG, Botto C, Villegas L, Garcia M, Curtis CF, 2000. Parasitological indicators of onchocerciasis relevant to ivermectin control programmes in the Amazonian focus of Southern Venezuela. Parasitology 121 : 527–534.
  34. Carabin H, Escalona M, Marshall C, Vivas-Martinez S, Botto C, Joseph L, Basanez MG, 2003. Prediction of community prevalence of human onchocerciasis in the Amazonian onchocerciasis focus: Bayesian approach. Bull World Health Organ 81 : 482–490.
  35. Emukah EC, Osuoha E, Miri ES, Onyenama J, Amazigo U, Obijuru C, Osuji N, Ekeanyanwu J, Amadiegwu S, Korve K, Richards FO, 2004. A longitudinal study of impact of repeated mass ivermectin treatment on clinical manifestations of onchocerciasis in Imo State, Nigeria. Am J Trop Med Hyg 70 : 556–561.
  36. Ayong LS, Tume CB, Wembe FE, Simo G, Asonganyi T, Lando G, Ngu JL, 2005. Development and evaluation of an antigen detection dipstick assay for the diagnosis of human ohchocerciasis. Trop Med Int Health 10 : 228–233.
  37. Dietz K, 1982. The population dynamics of onchocerciasis. Anderson R, ed. Population Dynamics of Infectious Disease. Chapman and Hall, 209–241.
  38. Davies JB, 1993. Description of a computer model of forest onchocerciasis transmission and its application to field scenarios of vector control and chemotherapy. Ann Trop Med Parasitol 87 : 41–63.
  39. Basanez MG, Ricardez-Esquinca J, 2001. Models for the population biology and control of human onchocerciasis. Trends Parasitol 17 : 430–438.
  40. Plaisier AP, Van Oortmarssen GJ, Habbema JD, Remme J, Alley ES, 1990. ONCHOSIM: a model and computer simulation program for the transmission and control of onchocerciasis. Comput Methods Programs Biomed 31 : 43–56.
  41. Basanez MG, Remme JH, Alley ES, Bain O, Shelley AJ, Medley GF, Anderson RM, 1995. Density-dependent processes in the transmission of human onchocerciasis: relationship between the numbers of microfilariae ingested and successful larval development in the simuliid vector. Parasitology 110 : 409–427.
  42. Basanez MG, Yarzabal L, Frontado HL, Villamizar NJ, 2000. Onchocerca-Simulium complexes in Venezuela: can human onchocerciasis spread outside its present endemic areas? Parasitology 120 : 143–160.
  43. Galvani AP, Gupta S, 1998. The effects of mating probability on the population genetics of nematodes. J Helminthol 72 : 295–300.
  44. Anderson R, 1982. The population dynamics and control of hookworm and roundworm infections. Anderson R, ed. Population Dynamics of Infectious Disease. Chapman and Hall. pp. 67–106.
  45. Duerr HP, Dietz K, Schulz-Keyb H, Buttner DW, Eichner M, 2004. The relationships between the burden of adult parasites, host age and the microfilarial density in human onchocerciasis. International Journal for Parasitology 34 : 463–473.
  46. Boussinesq M, Chippaux JP, Ernould JC, Quillevere D, Prod’hon J, 1995. Effect of repeated treatments with ivermectin on the incidence of onchocerciasis in northern Cameroon. Am J Trop Med Hyg 53 : 63–67.
  47. Amazigo U, Noma M, Boatin BA, Etya’ale DE, Seketeli A, Dadzie KY, 1998. Delivery systems and cost recovery in Mectizan treatment for onchocerciasis. Ann Trop Med Parasitol 92 : S23–S31.
  48. Duke BO, 1990. Onchocerciasis (river blindness)—Can it be eradicated? Parasitol Today 6 : 82–84.
  49. Okeibunor JC, Ogungbemi MK, Sama M, Gbeleou SC, Oyene U, Remme JH, 2004. Additional health and development activities for community-directed distributors of ivermectin: threat or opportunity for onchocerciasis control? Trop Med Int Health 9 : 887–896.
  50. Benton B, Bump J, Seketeli A, Liese B, 2002. Partnership and promise: evolution of the African river-blindness campaigns. Ann Trop Med Parasitol 96 : S5–S14.
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  • Received : 12 Jan 2006
  • Accepted : 08 May 2006

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