title: Evidence for suppression of Onchocerca volvulus transmission in the Oaxaca focus in Mexico.
abstract: Entomologic and serologic surveys were performed in four sentinel communities in the Oaxaca focus in southern Mexico to assess the level of transmission and exposure incidence to Onchocerca volvulus. All communities have been receiving ivermectin mass treatment twice per year since 1997. In one community, parasite DNA was detected by polymerase chain reaction-enzyme-linked immunosorbent assay in 2004 in one pool of 50 vector heads of 170 such pools (8,500 flies) examined, which indicated an estimated transmission potential of 6.7 third-stage larvae/person/year. No evidence for transmission was found in the three other communities in 13,650 flies examined. All persons in a cohort consisting of 117 children in the four communities remained serologically negative for antibodies recognizing a cocktail of recombinant antigens over a four-year period from 2001 to 2004, which indicated an exposure incidence of 0%. Taken together, these data suggest that transmission has been suppressed in the four communities.
authors.affiliation: Centro de Biotecnología Genómica, Instituto Politécnico Nacional, Boulevard del Maestro Esquina Elías Piña, Col. Narciso Mendoza, Reynosa, Tamaulipas, Mexico. drmarodriguez@hotmail.com
authors.forename: Mario A
authors.initials: MA
authors.lastname: Rodríguez-Pérez
authors.forename: Cristian
authors.initials: C
authors.lastname: Lizarazo-Ortega
authors.forename: Hassan K
authors.initials: HK
authors.lastname: Hassan
authors.forename: Alfredo
authors.initials: A
authors.lastname: Domínguez-Vásquez
authors.forename: Jorge
authors.initials: J
authors.lastname: Méndez-Galván
authors.forename: Patricia
authors.initials: P
authors.lastname: Lugo-Moreno
authors.forename: Mauricio
authors.initials: M
authors.lastname: Sauerbrey
authors.forename: Frank
authors.initials: F
authors.lastname: Richards
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Unnasch
mesh_terms: D000818:Animals; D000947:Antigens, Helminth / Q000032:analysis; D018509:DNA, Helminth / Q000032:analysis; D004797:Enzyme-Linked Immunosorbent Assay; D005369:Filaricides / Q000627:therapeutic use; D006801:Humans; D015994:Incidence; D007303:Insect Vectors / Q000469:parasitology; D007559:Ivermectin / Q000627:therapeutic use; D008800:Mexico / Q000453:epidemiology; D017181:Onchocerca volvulus / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification*; D009855:Onchocerciasis / Q000453:epidemiology* / Q000209:etiology / Q000517:prevention & control* / Q000635:transmission; D016133:Polymerase Chain Reaction; D012843:Simuliidae / Q000469:parasitology
chemical_list: D000947:Antigens, Helminth; D018509:DNA, Helminth; D005369:Filaricides; D007559:Ivermectin