title: The reliability of anterior segment lesions as indicators of onchocercal eye disease in Guatemala.
abstract: World Health Organization certification criteria for onchocerciasis elimination use anterior segment eye lesion prevalence as an indicator of mass ivermectin treatment program success. Lesions either contain visible microfilaria (noninflammatory punctate keratitis [PK] or microfilariae in anterior chamber [MFAC]), or microfilaria obscured by inflammation (inflammatory PK). To assess the utility of these disease indicators, two experienced ophthalmologists independently examined persons from endemic (N = 325) and nonendemic (N = 348) Guatemalan communities. Thirty-six (11.1%) and nine (2.6%) persons from endemic and nonendemic areas respectively had lesions found by either ophthalmologist (prevalence ratio = 4.3, 95% CI 2.1-8.8, P < 0.001). All lesions in nonendemic areas were inflammatory PK in whom no persons were seropositive for onchocerciasis. Overall, observer agreement was moderate (Kappa = 0.49), and most (61%) discordance occurred with inflammatory PK lesions. Our findings suggest that inflammatory punctate keratitis is neither a specific nor a reliable indicator of onchocercal eye disease. Future prevalence surveys should rely upon noninflammatory lesions as disease indicators.
authors.affiliation: Division of Parasitic Diseases, US Centers for Disease Control and Prevention, Atlanta, GA 30341, USA. winthrop@ohsu.edu
authors.forename: Kevin L
authors.initials: KL
authors.lastname: Winthrop
authors.forename: Roberto
authors.initials: R
authors.lastname: Proaño
authors.forename: Orlando
authors.initials: O
authors.lastname: Oliva
authors.forename: Byron
authors.initials: B
authors.lastname: Arana
authors.forename: Carlos
authors.initials: C
authors.lastname: Mendoza
authors.forename: Alfredo
authors.initials: A
authors.lastname: Dominguez
authors.forename: Josef
authors.initials: J
authors.lastname: Amann
authors.forename: George
authors.initials: G
authors.lastname: Punkosdy
authors.forename: Carlos
authors.initials: C
authors.lastname: Blanco
authors.forename: Robert
authors.initials: R
authors.lastname: Klein
authors.forename: Mauricio
authors.initials: M
authors.lastname: Sauerbrey
authors.forename: Frank
authors.initials: F
authors.lastname: Richards
mesh_terms: D000818:Animals; D000867:Anterior Chamber / Q000469:parasitology*; D005128:Eye Diseases / Q000469:parasitology; D006166:Guatemala / Q000453:epidemiology; D006801:Humans; D015588:Observer Variation; D009854:Onchocerca / Q000302:isolation & purification; D015827:Onchocerciasis, Ocular / Q000453:epidemiology / Q000473:pathology*; D015995:Prevalence; D015203:Reproducibility of Results