Field evaluation of a coproantigen detection test for fascioliasis diagnosis and surveillance in human hyperendemic areas of Andean countries

PLoS Negl Trop Dis. 2012;6(9):e1812. doi: 10.1371/journal.pntd.0001812. Epub 2012 Sep 13.

Abstract

Background: Emergence of human fascioliasis prompted a worldwide control initiative including a pilot study in a few countries. Two hyperendemic areas were chosen: Huacullani, Northern Altiplano, Bolivia, representing the Altiplanic transmission pattern with high prevalences and intensities; Cajamarca valley, Peru, representing the valley pattern with high prevalences but low intensities. Coprological sample collection, transport and study procedures were analyzed to improve individual diagnosis and subsequent treatments and surveillance activities. Therefore, a coproantigen-detection technique (MM3-COPRO ELISA) was evaluated, using classical techniques for egg detection for comparison.

Methodology and findings: A total of 436 and 362 stool samples from schoolchildren of Huacullani and Cajamarca, respectively, were used. Positive samples from Huacullani were 24.77% using the MM3-COPRO technique, and 21.56% using Kato-Katz. Positive samples from Cajamarca were 11.05% using MM3-COPRO, and 5.24% using rapid sedimentation and Kato-Katz. In Huacullani, using Kato-Katz as gold standard, sensitivity and specificity were 94.68% and 98.48%, respectively, and using Kato-Katz and COPRO-ELISA test together, they were 95.68% and 100%. In Cajamarca, using rapid sedimentation and Kato-Katz together, results were 94.73% and 93.58%, and using rapid sedimentation, Kato-Katz and copro-ELISA together, they were 97.56% and 100%, respectively. There was no correlation between coproantigen detection by optical density (OD) and infection intensity by eggs per gram of feces (epg) in Cajamarca low burden cases (<400 epg), nor in Huacullani high burden cases (≥ 400 epg), although there was in Huacullani low burden cases (<400 epg). Six cases of egg emission appeared negative by MM3-COPRO, including one with a high egg count (1248 epg).

Conclusions: The coproantigen-detection test allows for high sensitivity and specificity, fast large mass screening capacity, detection in the chronic phase, early detection of treatment failure or reinfection in post-treated subjects, and usefulness in surveillance programs. However, this technique falls short when evaluating the fluke burden on its own.

Publication types

  • Comparative Study
  • Evaluation Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adolescent
  • Antigens, Helminth / analysis*
  • Bolivia
  • Child
  • Child, Preschool
  • Clinical Laboratory Techniques / methods*
  • Enzyme-Linked Immunosorbent Assay / methods
  • Fascioliasis / diagnosis*
  • Feces / chemistry
  • Feces / parasitology*
  • Female
  • Humans
  • Male
  • Mass Screening / methods
  • Parasitology / methods*
  • Peru
  • Sensitivity and Specificity
  • Specimen Handling / methods

Substances

  • Antigens, Helminth

Grants and funding

This study was funded by projects number SAF2006-09278 and SAF No. 2010-20805 of the Spanish Ministry of Science and Technology, Madrid, and by Red de Investigación de Centros de Enfermedades Tropicales (RICET) grant number ISCIII-RETIC RD06/0021/0017 of the Programa de Redes Temáticas de Investigación Cooperativa (RETICS/FEDER) of the Fondo de Investigación Sanitaria (FIS), Ministry of Health, Madrid, Spain. Pilot interventions on fascioliasis in children carried out in the endemic areas of the Northern Altiplano, Bolivia, and Cajamarca province, Peru, were funded by Preventive Chemotherapy and Transmission Control (PCT/NTD), Department of Control of Neglected Tropical Diseases, World Health Organization (WHO/OMS), Geneva, Switzerland. Joint coordination activities also carried out within project number RLA5049 of the International Atomic Energy Agency (Animal Production and Health Section, Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture, Department of Nuclear Sciences and Applications, IAEA Headquaters Vienna, Austria). The funding agencies had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript. The content is solely the responsibility of the authors and does not necessarily represent the official views of the funding and supporting agencies.