title: Evaluation of a field test for antibodies against Chlamydia trachomatis during trachoma surveillance in Nepal.
abstract: OBJECTIVE
  Testing for antibodies to Chlamydia trachomatis has potential as a surveillance tool. Our evaluation compares lateral flow assays (LFAs) during surveillance surveys in Nepal with Multiplex bead array (MBA). Fifty children were randomly sampled from each of 15 random clusters in two districts of Nepal. Finger prick blood samples were collected from 1509 children and tested onsite for anti-Pgp3 antibodies by LFA. The LFA was read at 30min as negative, positive, or invalid. Tests results were also rated as difficult to read ("equivocal"). Blood was processed at Johns Hopkins University using the MBA.
  
  
  RESULTS
  The LFA had agreement of 40.0% for MBA-positive samples and 99.3% for MBA-negative samples. Inter-reader reliability was kappa=0.65 (95% CI=0.56-0.74). If the equivocal results (7%) could be decreased, reliability could be improved.
  
  
  CONCLUSIONS
  Further optimization and testing of the LFA test are needed to improve agreement with MBA and the interpretation of the results.
authors.affiliation: Dana Center for Preventive Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD.
authors.forename: Michelle J
authors.initials: MJ
authors.lastname: Sun
authors.affiliation: Dana Center for Preventive Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD.
authors.forename: Andrea I
authors.initials: AI
authors.lastname: Zambrano
authors.affiliation: International Chlamydia Laboratory, Johns Hopkins University Baltimore, MD, USA.
authors.forename: Laura
authors.initials: L
authors.lastname: Dize
authors.affiliation: Dana Center for Preventive Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD.
authors.forename: Beatriz
authors.initials: B
authors.lastname: Munoz
authors.affiliation: IHRC, Inc. Contractor at the Centers for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Sarah
authors.initials: S
authors.lastname: Gwyn
authors.affiliation: Nepal Netra Jyoti Sangh, Kathmandu, Nepal.
authors.forename: Sailesh
authors.initials: S
authors.lastname: Mishra
authors.affiliation: Division of Parasitic Diseases and Malaria, Center for Disease Control and Prevention, Atlanta, GA, USA.
authors.forename: Diana L
authors.initials: DL
authors.lastname: Martin
authors.affiliation: Nepal Netra Jyoti Sangh, Kathmandu, Nepal.
authors.forename: Shekhar
authors.initials: S
authors.lastname: Sharma
authors.affiliation: Dana Center for Preventive Ophthalmology, Wilmer Eye Institute, Johns Hopkins University, Baltimore, MD. Electronic address: shwest@jhmi.edu.
authors.forename: Sheila K
authors.initials: SK
authors.lastname: West
mesh_terms: D000907:Antibodies, Bacterial / Q000097:blood*; D000942:Antigens, Bacterial / Q000276:immunology; D001426:Bacterial Proteins / Q000276:immunology; D002648:Child; D002675:Child, Preschool; D002692:Chlamydia trachomatis / Q000276:immunology*; D002846:Chromatography, Affinity / Q000379:methods*; D062665:Epidemiological Monitoring; D005260:Female; D006801:Humans; D018189:Immunomagnetic Separation / Q000379:methods*; D007223:Infant; D008297:Male; D009390:Nepal / Q000453:epidemiology; D012698:Serologic Tests / Q000379:methods*; D014141:Trachoma / Q000175:diagnosis* / Q000453:epidemiology
chemical_list: D000907:Antibodies, Bacterial; D000942:Antigens, Bacterial; D001426:Bacterial Proteins; C082169:pgp3 protein, Chlamydia
keywords: Antibodies; C. trachomatis; Nepal; Population surveillance; Trachoma