title: Elimination of Onchocerciasis from Mexico.
abstract: BACKGROUND
  Mexico is one of the six countries formerly endemic for onchocerciasis in Latin America. Transmission has been interrupted in the three endemic foci of that country and mass drug distribution has ceased. Three years after mass drug distribution ended, post-treatment surveillance (PTS) surveys were undertaken which employed entomological indicators to check for transmission recrudescence.
  
  
  RESULTS
  In-depth entomologic assessments were performed in 18 communities in the three endemic foci of Mexico. None of the 108,212 Simulium ochraceum s.l. collected from the three foci were found to contain parasite DNA when tested by polymerase chain reaction-enzyme-linked immunosorbent assay (PCR-ELISA), resulting in a maximum upper bound of the 95% confidence interval (95%-ULCI) of the infective rate in the vectors of 0.035/2,000 flies examined. This is an order of magnitude below the threshold of a 95%-ULCI of less than one infective fly per 2,000 flies tested, the current entomological criterion for interruption of transmission developed by the international community. The point estimate of seasonal transmission potential (STP) was zero, and the upper bound of the 95% confidence interval for the STP ranged from 1.2 to 1.7 L3/person/season in the different foci. This value is below all previous estimates for the minimum transmission potential required to maintain the parasite population.
  
  
  CONCLUSIONS
  The results from the in-depth entomological post treatment surveillance surveys strongly suggest that transmission has not resumed in the three foci of Mexico during the three years since the last distribution of ivermectin occurred; it was concluded that transmission remains undetectable without intervention, and Onchocerca volvulus has been eliminated from Mexico.
authors.affiliation: Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Reynosa, Tamaulipas, México.
authors.forename: Mario A
authors.initials: MA
authors.lastname: Rodríguez-Pérez
authors.affiliation: Dirección General de Programas Preventivos, Centro Nacional de Programas Preventivos y Control de Enfermedades, Secretaría de Salud, Colonia Escandón, Delegación Miguel Hidalgo, Mexico City, México.
authors.forename: Nadia A
authors.initials: NA
authors.lastname: Fernández-Santos
authors.affiliation: Dirección General de Programas Preventivos, Centro Nacional de Programas Preventivos y Control de Enfermedades, Secretaría de Salud, Colonia Escandón, Delegación Miguel Hidalgo, Mexico City, México.
authors.forename: María E
authors.initials: ME
authors.lastname: Orozco-Algarra
authors.affiliation: Dirección General de Programas Preventivos, Centro Nacional de Programas Preventivos y Control de Enfermedades, Secretaría de Salud, Colonia Escandón, Delegación Miguel Hidalgo, Mexico City, México.
authors.forename: José A
authors.initials: JA
authors.lastname: Rodríguez-Atanacio
authors.affiliation: Onchocerciasis Elimination Program for the Americas, Guatemala City, Guatemala.
authors.forename: Alfredo
authors.initials: A
authors.lastname: Domínguez-Vázquez
authors.affiliation: Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Reynosa, Tamaulipas, México.
authors.forename: Kristel B
authors.initials: KB
authors.lastname: Rodríguez-Morales
authors.affiliation: Consejería de Educación, Madrid, España, Leganés, Madrid, Spain.
authors.forename: Olga
authors.initials: O
authors.lastname: Real-Najarro
authors.affiliation: Programa de Eliminación de la Oncocercosis en Chiapas, Departamento de Prevención y Control de Enfermedades Transmitidas por Vector, Secretaría de Salud Unidad Administrativa, Tuxtla Gutiérrez, Chiapas, México.
authors.forename: Francisco G
authors.initials: FG
authors.lastname: Prado-Velasco
authors.affiliation: Department of Entomology and Plant Pathology, Auburn University, Auburn, Alabama, United States of America.
authors.forename: Eddie W
authors.initials: EW
authors.lastname: Cupp
authors.affiliation: River Blindness Program, Carter Center, Atlanta, Georgia, United States of America.
authors.forename: Frank O
authors.initials: FO
authors.lastname: Richards
authors.affiliation: Global Health Infectious Disease Research Program, Department of Global Health,University of South Florida, Tampa, Florida, United States of America.
authors.forename: Hassan K
authors.initials: HK
authors.lastname: Hassan
authors.affiliation: Dirección General de Programas Preventivos, Centro Nacional de Programas Preventivos y Control de Enfermedades, Secretaría de Salud, Colonia Escandón, Delegación Miguel Hidalgo, Mexico City, México.
authors.forename: Jesús F
authors.initials: JF
authors.lastname: González-Roldán
authors.affiliation: Subsecretaría de Prevención y Promoción de la Salud, Secretaría de Salud, Colonia Juárez, Delegación Cuauhtémoc, México, D.F., México.
authors.forename: Pablo A
authors.initials: PA
authors.lastname: Kuri-Morales
authors.affiliation: Global Health Infectious Disease Research Program, Department of Global Health,University of South Florida, Tampa, Florida, United States of America.
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Unnasch
mesh_terms: D000818:Animals; D000871:Anthelmintics / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007303:Insect Vectors / Q000469:parasitology / Q000502:physiology; D007559:Ivermectin / Q000008:administration & dosage; D008297:Male; D008800:Mexico / Q000453:epidemiology; D017181:Onchocerca volvulus / Q000235:genetics / Q000302:isolation & purification / Q000502:physiology; D009855:Onchocerciasis / Q000188:drug therapy / Q000453:epidemiology / Q000517:prevention & control* / Q000635:transmission; D012843:Simuliidae / Q000469:parasitology* / Q000502:physiology
chemical_list: D000871:Anthelmintics; D007559:Ivermectin