title: Ring-screening to control endemic transmission of Taenia solium.
abstract: BACKGROUND
  Taenia solium is a major cause of preventable epilepsy in developing nations. Screening and treatment of human intestinal stage infection (taeniasis) within high-risk foci may reduce transmission and prevent epilepsy by limiting human exposure to infective eggs. We piloted a ring-strategy that involves screening and treatment for taeniasis among households located nearby pigs heavily-infected with the larval stage (cysticercosis). These pigs mark areas of increased transmission and can be identified by tongue examination.
  
  
  METHODS
  We selected two villages in northern Peru for a controlled prospective interventional cohort pilot study. In the intervention village (1,058 residents) we examined the tongues of all pigs every 4 months for nodules characteristic of cysticercosis. We then screened all residents living within 100-meters of any tongue-positive pig using enzyme-linked immunosorbent assay to detect Taenia antigens in stool. Residents with taeniasis were treated with niclosamide. In both the intervention and control (753 residents) we measured incidence of exposure by sampling the pig population every 4 months for serum antibodies against cysticercosis using enzyme-linked immunoelectrotransfer blot.
  
  
  RESULTS
  Baseline seroincidence among pigs born during the study was 22.6 cases per 100 pigs per-month (95% confidence interval [CI] 17.0-30.0) in the intervention and 18.1 (95% CI 12.7-25.9) in the control. After one year we observed a 41% reduction in seroincidence in the intervention village compared to baseline (incidence rate ratio 0.59, 95% CI 0.41-0.87) while the seroincidence in the control village remained unchanged. At study end, the prevalence of taeniasis was nearly 4 times lower in the intervention than in the control (prevalence ratio 0.28, 95% CI 0.08-0.91).
  
  
  CONCLUSIONS
  Ring-screening reduced transmission of T. solium in this pilot study and may provide an effective and practical approach for regions where resources are limited. However, this strategy requires validation in larger populations over a greater period of time.
authors.affiliation: Department of Public Health and Preventive Medicine, Oregon Health & Science University, Portland, Oregon, United States of America.
authors.forename: Seth E
authors.initials: SE
authors.lastname: O'Neal
authors.affiliation: Cysticercosis Elimination Program and Center for Global Health - Tumbes, Universidad Peruana Cayetano Heredia, Tumbes, Peru.
authors.forename: Luz M
authors.initials: LM
authors.lastname: Moyano
authors.affiliation: Cysticercosis Elimination Program and Center for Global Health - Tumbes, Universidad Peruana Cayetano Heredia, Tumbes, Peru.
authors.forename: Viterbo
authors.initials: V
authors.lastname: Ayvar
authors.affiliation: Instituto de Ciencias Neurológicas, Lima, Peru.
authors.forename: Silvia
authors.initials: S
authors.lastname: Rodriguez
authors.affiliation: School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru.
authors.forename: Cesar
authors.initials: C
authors.lastname: Gavidia
authors.affiliation: Division of Parasitic Diseases and Malaria, Centers for Disease Control, Atlanta, Georgia, United States of America.
authors.forename: Patricia P
authors.initials: PP
authors.lastname: Wilkins
authors.affiliation: Department of International Health, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America; Department of Microbiology, School of Sciences, Universidad Peruana Cayetano Heredia, Lima, Peru.
authors.forename: Robert H
authors.initials: RH
authors.lastname: Gilman
authors.affiliation: Cysticercosis Elimination Program and Center for Global Health - Tumbes, Universidad Peruana Cayetano Heredia, Tumbes, Peru; Instituto de Ciencias Neurológicas, Lima, Peru; Department of Microbiology, School of Sciences, Universidad Peruana Cayetano Heredia, Lima, Peru.
authors.forename: Hector H
authors.initials: HH
authors.lastname: Garcia
authors.affiliation: School of Veterinary Medicine, Universidad Nacional Mayor de San Marcos, Lima, Peru.
authors.forename: Armando E
authors.initials: AE
authors.lastname: Gonzalez
mesh_terms: D000818:Animals; D000909:Antibodies, Helminth / Q000097:blood*; D000923:Anticestodal Agents / Q000627:therapeutic use; D002675:Child, Preschool; D003551:Cysticercosis / Q000453:epidemiology; D005243:Feces; D005260:Female; D006801:Humans; D015994:Incidence; D008297:Male; D009534:Niclosamide / Q000627:therapeutic use; D010568:Peru / Q000453:epidemiology; D010865:Pilot Projects; D015995:Prevalence; D011446:Prospective Studies; D013552:Swine; D013553:Swine Diseases / Q000453:epidemiology / Q000469:parasitology*; D041201:Taenia solium; D013622:Taeniasis / Q000453:epidemiology / Q000635:transmission / Q000662:veterinary*; D014059:Tongue / Q000469:parasitology*; D015047:Zoonoses
chemical_list: D000909:Antibodies, Helminth; D000923:Anticestodal Agents; D009534:Niclosamide