Volume 70, Issue 1
  • ISSN: 0002-9637
  • E-ISSN: 1476-1645


To investigate the impact of mass ivermectin treatments in Mexico on transmission, entomologic surveys were carried out in the two endemic states of Oaxaca and Chiapas. The data suggest that substantial progress towards the goal of elimination has been made. A comparison pre- and post-ivermectin data from a community in Southern Chiapas showed a 97% decrease in seasonal transmission potential, but some level of polymerase chain reaction positivity was still detectable. In other communities from northern Chiapas and Oaxaca where there are no baseline data, there was an absence or near absence of infective flies. Residual transmission was not evenly distributed because differences were seen in the infection and infective rates from different catch points. These findings suggest that while substantial progress towards elimination has been made in Mexico, it may be necessary to modify ivermectin distribution strategies to eliminate transmission in areas where transmission persists.


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  1. World Health Organization, 1991. Executive Summary. First Inter American Conference on Onchocerciasis. Washington, DC: Pan American Health Organization/World Health Organization.
  2. World Health Organization, 1995. Onchocerciasis and its control. World Health Organ Tech Rep Ser 852.
  3. IACO, 2001. Relatoría de la XI Conferencia Interamericana sobre Oncocercosis (IACO). Mexico, D. F. Noviembre 27–29, 2001.
  4. World Health Organization, 2001. Certification of Elimination of Human Oonchocerciasis: Criteria and Procedures. Geneva: World Health Organization. Document WHO/CDS/CPE/CEE’2001.
  5. Cupp EW, Ochoa JO, Collins RC, Cupp MS, González-Peralta C, Castro J, Zea-Flores G, 1992. The effects of repetitive community-wide ivermectin treatment on transmission of Onchocerca volvulus in Guatemala. Am J Trop Med Hyg 47 : 170–180. [Google Scholar]
  6. Guderian RH, Anselmi M, Espinel M, Mancero T, Rivadeneira G, Proaño R, Calvopiña HM, Vieira JC, Cooper PJ, 1997. Successful control of onchocerciasis with community-based ivermectin distribution in the Rio Santiago focus in Ecuador. Trop Med Int Health 2 : 982–988. [Google Scholar]
  7. Guevara AG, Vieria JC, Lilley BG, López A, Vieira N, Rumbea J, Collins R, Katholi CR, Unnasch TR, 2003. Entomological evaluation by pool screen polymerase chain reaction of Onchocerca volvulus transmission in Ecuador following mass Mectizan distribution. Am J Trop Med Hyg 68 : 222–227. [Google Scholar]
  8. Hougar JM, Alley ES, Yaméogo L, Dadzie KY, Boatin BA, 2001. Eliminating onchocerciasis after 14 years of vector control: a proved strategy. J Infect Dis 184 : 497–503. [Google Scholar]
  9. Rodríguez-Pérez MA, Rodríguez MH, Margeli-López HM, Rivás-AlcaláAR, 1995. Effect of semiannual treatments of ivermectin on the prevalence and intensity of Onchocerca volvulus skin infection, ocular lesions, and infectivity of Simulium ochraceum populations in southern Mexico. Am J Trop Med Hyg 52 : 429–434. [Google Scholar]
  10. Rodríguez-Pérez MA, Danis-Lozano R, Rodríguez MH, Bradley JE, 1999a. Comparison of serological and parasitological assessments of Onchocerca volvulus transmission after 7 years of mass ivermectin treatment in Mexico. Trop Med Int Health 4 : 98–104. [Google Scholar]
  11. Rodríguez-Pérez MA, Danis-Lozano R, Rodríguez MH, Unnasch TR, Bradley JE, 1999b. Detection of Onchocerca volvulus infection in Simulium ochraceum sensu lato: Comparison of a PCR assay and fly dissection in a Mexican hypoendemic community. Parasitology 119 : 613–619. [Google Scholar]
  12. Brandling-Bennett AD, Anderson J, Fuglsang H, Collins RC, 1981. Onchocerciasis in Guatemala. Epidemiology in fincas with various intensities of infection. Am J Trop Med Hyg 30 : 970–981. [Google Scholar]
  13. Rodríguez-Pérez MA, Reyes-Villanueva F, 1994. Efecto de la ivermectina sobre la transmisión de Onchocerca volvulus en México. Salud Publica Mex 36 : 281–290. [Google Scholar]
  14. Vázquez-Castellanos JL, 199l. Cafeticultura e historia social de la oncocercosis en el Soconusco, estado de Chiapas, México. Salud Publica Mex 33 : 124–135. [Google Scholar]
  15. Davies JB, 1968. A Review of Past and Present Aspects of Simulium Control in Mexico Together with Recommendations for the Future Conduct of Control Schemes and an Outline of an Erradication Scheme in the North Focus of Onchocerciasis in Chiapas State. Washington, DC: Pan American Health Organization.
  16. Martín-Tellaeche A, Ramírez-Hernández J, Santos-Preciado JI, Galván J, 1998. Onchocersiasis: changes in transmission in Mexico. Ann Trop Med Parasitol 1 : S117–S119. [Google Scholar]
  17. Meredith SEO, Lando G, Gbakima A, Zimmerman PA, Unnasch TR, 1991. Onchocerca volvulus: application of the polymerase chain reaction to identification and strain differentiation of the parasite. Exp Parasitol 73 : 335–344. [Google Scholar]
  18. Zimmerman PA, Dadzie KY, DeSole G, Remme J, Soumbey-Alley E, Unnasch TR, 1992. Onchocerca volvulus DNA probe classification correlates with epidemiological patterns of blindness. J Infect Dis 165 : 964–968. [Google Scholar]
  19. Zimmerman PA, Toè L, Unnasch TR, 1993. Desing of Onchocerca DNA probes based upon analysis of a repeated sequence family. Mol Biochem Parasitol 58 : 259–268. [Google Scholar]
  20. Basáñez MG, Rodríguez-Pérez MA, Reyes-Villanueva F, Collins RC, Rodríguez MH, 1998. Determination of samples sizes for the estimation of Onchocerca volvulus (Filarioidea: Onchocercidae) infection rates in biting populations of Simulium ochraceum s. l. (Diptera: Simuliidae) and its application to ivermectin control programs. J Med Entomol 35 : 745–757. [Google Scholar]
  21. Katholi CR, Toé L, Merriweather A, Unnasch TR, 1995. Determining the prevalence of Onchocerca volvulus infection in vector populations by polymerase chain reaction screening of pools of black flies. J Infect Dis 172 : 1414–1417. [Google Scholar]
  22. Rodríguez-Pérez MA, Rivás-Alcalá R, 1992. Age structure of Simulium ochraceum and transmission of Onchocerca volvulus in Mexico. Clark GG, Suárez MF, organizers. Mosquito Vector Control and Biology in Latin America – A Second Symposium. J Am Mosq Control Assoc 8 : 305–317. [Google Scholar]
  23. Cupp EW, Collins RC, 1979. The gonotrophic cycle in Simulium ochraceum. Am J Trop Med Hyg 28 : 422–426. [Google Scholar]
  24. Grillet ME, Basáñez MG, Vivas-Martínez S, Villamizar N, Frontado H, Cortez J, Coronel P, Botto C, 2001. Human onchocerciasis in the Amazonian area of southern Venezuela: spatial and temporal variation in biting and parity rates of black flies (Diptera:Simuliidae) vectors. J Med Entomol 38 : 520–530. [Google Scholar]
  25. Unnasch TR, Meredith SEO, 1996. The use of degenerate primers in conjunction with strain and species oligonucleotides to classify Onchocerca volvulus. Clapp JP. ed. Methods in Molecular Biology. Volume 50. Species Diagnostics Protocols: PCR and Other Nucleic Acid Methods. Totowa, NJ: Humana Press, Inc., 293–303.
  26. Nutman TB, Zimmerman PA, Kubofcik J, Kostyu DD, 1994. A universally applicable diagnostic approach to filarial and other infections. Parasitol Today 10 : 239–243. [Google Scholar]
  27. Yamèogo L, Toè L, Hougard JM, Boatin BA, Unnasch TR, 1999. Pool screen polymerase chain reaction 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. Am J Trop Med Hyg 60 : 124–128. [Google Scholar]
  28. Walsh JF, Davies JB, LeBerre R, Garms R, 1978. Standardization of criteria for assessing the effects of Simulium control in onchocerciasis control program. Trans R Soc Trop Med Hyg 72 : 675–676. [Google Scholar]
  29. Kotz S, Johnson NL, Read CB, 1988. Method of statistical differentials. Encyclopedia of Statistical Sciences. New York: John Wiley & Sons, 646–647.
  30. Cupp EW, 2003. Vector species, transmission efficiency, and frequency of ivermectin treatment. Dadzie Y, Neira M, Hopkins D, eds. Final Report of the Conference on Eradicability of Onchocerciasis. 51–52.
  31. Ortega M, Oliver M, Ramírez A, 1992. Entomología de la oncocercosis en el Soconusco, Chiapas. VI. Estudios cuantitativos de la transmisión de Onchocerca volvulus por tres especies de simúlidos en una comunidad de alta endemia. Rev Fac Med UNAM 35 : 95–103. [Google Scholar]
  32. Collins RC, Lehmann T, Vieira-García JC, Guderian RH, 1995. Vector competence of Simulium exiguum for Onchocerca volvulus: implications for the epidemiology of onchocerciasis. Am J Trop Med Hyg 52 : 213–218. [Google Scholar]
  33. Cupp EW, Ochoa JO, Collins RC, Ramberg FR, Zea-Flores G, 1989. The effect of multiple ivermectin treatments on infection of Simulium ochraceum with Onchocerca volvulus. Am J Trop Med Hyg 40 : 501–506. [Google Scholar]
  34. Basañez MG, Boussinesq M, Próheon J, Frontado H, Villamizar NJ, Medley GF, Anderson RM, 1994. Density-dependent processes in the transmission of human onchocerciasis: intensity of microfilariae in the skin and their uptake by the simuliid host. Parasitology 108 : 115–127. [Google Scholar]
  35. Basáñez MG, Remme JHF, Alley ES, Bain O, Shelley AJ, Medley FG, 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. [Google Scholar]
  36. Anderson RM, May RM, 1985. Helminth infections of humans; mathematical models, population dynamics, and control. Adv Parasitol 24 : 1–101. [Google Scholar]
  37. Boatin B, Molyneux DH, Hougard JM, Christensen OW, Alley ES, Yamèogo L, Seketeli A, Dadzie KY, 1997. Patterns of epidemiology and control of onchocerciasis in West Africa. J Helminthol 71 : 91–101. [Google Scholar]
  38. Remme JHF, 1995. Estimation and prediction in tropical disease control: the example of onchocerciasis. Mollison D, ed. Epidemic Models: Their Structure and Relation to Data. Cambridge, United Kingdom: Cambridge University Press, 372–392.
  39. Meredith SEO, Dull HB, 1998. Onchocerciasis: the first decade of mectizan™ treatment. Parasitol Today 14 : 472–474. [Google Scholar]

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  • Received : 11 Aug 2003
  • Accepted : 26 Sep 2003

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