title: Assessing Ultrasonography as a Diagnostic Tool for Porcine Cysticercosis.
abstract: Taenia solium inflicts substantial neurologic disease and economic losses on rural communities in many developing nations. "Ring-strategy" is a control intervention that targets treatment of humans and pigs among clusters of households (rings) that surround pigs heavily infected with cysticerci. These pigs are typically identified by examining the animal's tongue for cysts. However, as prevalence decreases in intervened communities, more sensitive methods may be needed to identify these animals and to maintain control pressure. The purpose of this study was to evaluate ultrasonography as an alternative method to detect pigs heavily infected with T. solium cysts.
  
  
  
  We purchased 152 pigs representing all seropositive animals villagers were willing to sell from eight communities (pop. 2085) in Piura, Peru, where T. solium is endemic. Tongue and ultrasound examinations of the fore and hind-limbs were performed in these animals, followed by necropsy with fine dissection as gold standard to determine cyst burden. We compared the sensitivity and specificity of ultrasonography with tongue examination for their ability to detect heavy infection (≥ 100 viable cysts) in pigs. Compared to tongue examination, ultrasonography was more sensitive (100% vs. 91%) but less specific (90% vs. 98%), although these differences were not statistically significant. The greater sensitivity of ultrasound resulted in detection of one additional heavily infected pig compared to tongue examination (11/11 vs. 10/11), but resulted in more false positives (14/141 vs. 3/141) due to poor specificity.
  
  
  
  Ultrasonography was highly sensitive in detecting heavily infected pigs and may identify more rings for screening or treatment compared to tongue examination. However, the high false positive rate using ultrasound would result in substantial unnecessary treatment. If specificity can be improved with greater operator experience, ultrasonography may benefit ring interventions where control efforts have stalled due to inadequate sensitivity of tongue examination.
authors.affiliation: School of Public Health, Oregon Health & Science University and Portland State University, Portland, Oregon, United States of America.
authors.forename: Robert H
authors.identifier: 0000-0002-3165-0220
authors.initials: RH
authors.lastname: Flecker
authors.affiliation: School of Public Health, Oregon Health & Science University and Portland State University, Portland, Oregon, United States of America.
authors.forename: Ian W
authors.initials: IW
authors.lastname: Pray
authors.affiliation: School of Sciences, Department of Microbiology, Universidad Peruana Cayetano Heredia, Lima, Peru.|Instituto Peruano de Parasitologia Clinica y Experimental - INPPACE, Lima, Peru.
authors.forename: Saul J
authors.initials: SJ
authors.lastname: Santivaňez
authors.affiliation: Center for Global Health Tumbes, Universidad Peruana Cayetano Heredia, Tumbes, Peru.
authors.forename: Viterbo
authors.initials: V
authors.lastname: Ayvar
authors.affiliation: Center for Global Health Tumbes, Universidad Peruana Cayetano Heredia, Tumbes, Peru.
authors.forename: Ricardo
authors.initials: R
authors.lastname: Gamboa
authors.affiliation: Center for Global Health Tumbes, Universidad Peruana Cayetano Heredia, Tumbes, Peru.
authors.forename: Claudio
authors.initials: C
authors.lastname: Muro
authors.affiliation: Center for Global Health Tumbes, Universidad Peruana Cayetano Heredia, Tumbes, Peru.
authors.forename: Luz Maria
authors.initials: LM
authors.lastname: Moyano
authors.affiliation: Center for Global Health Tumbes, Universidad Peruana Cayetano Heredia, Tumbes, Peru.
authors.forename: Victor
authors.initials: V
authors.lastname: Benavides
authors.affiliation: School of Sciences, Department of Microbiology, Universidad Peruana Cayetano Heredia, Lima, Peru.|Center for Global Health Tumbes, Universidad Peruana Cayetano Heredia, Tumbes, Peru.
authors.forename: Hector H
authors.initials: HH
authors.lastname: Garcia
authors.affiliation: School of Public Health, Oregon Health & Science University and Portland State University, Portland, Oregon, United States of America.|Center for Global Health Tumbes, Universidad Peruana Cayetano Heredia, Tumbes, Peru.
authors.forename: Seth E
authors.initials: SE
authors.lastname: O'Neal
mesh_terms: D000818:Animals; D003551:Cysticercosis / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000469:parasitology / Q000662:veterinary*; D013552:Swine; D013553:Swine Diseases / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000469:parasitology; D041201:Taenia solium / Q000502:physiology; D014463:Ultrasonography / Q000379:methods* / Q000662:veterinary