title: Results of the National External Quality Assessment for Toxoplasmosis Serological Testing in China.
abstract: BACKGROUND
  Toxoplasmosis is typically diagnosed by serologic testing. External quality assessment (EQA) of clinical laboratories could ensure the accuracy and reliability of serological tests. We assessed the quality of toxoplasma serological assays in Chinese clinical laboratories by an EQA performed between 2004 and 2013 by the National Center for Clinical Laboratories.
  
  
  RESULTS
  EQA panels were prepared and shipped at room temperature to participating laboratories that employed toxoplasma IgG and IgM serological detection. By 2013, 5,384 EQA test reports for toxoplasma-specific IgM and 2,666 reports for toxoplasma-specific IgG were collected. Enzyme-linked immunosorbent (ELISA) and chemical immunofluorescent assays were the most commonly used detection methods. The overall coincidence rates of negative samples were better than those of positive samples. The overall EQA score for toxoplasma-specific IgM detection ranged between 84.3% and 99.6%. The ratio of laboratories that achieved correct IgG detection ranged from 61.1% to 99.3%. However, the inter- and intra-assay variabilities were found to be considerable. The most common problem was failure to detect low titers of antibody.
  
  
  CONCLUSIONS
  The EQA scheme showed an improvement in toxoplasma serological testing in China. However, further optimization of assay sensitivity to detect challenging samples remains a future challenge.
authors.affiliation: National Center for Clinical Laboratories, Beijing Hospital, Beijing, China; Graduate School, Peking Union Medical College, Chinese Academy of Medical Science, Beijing, China.
authors.forename: Kuo
authors.initials: K
authors.lastname: Zhang
authors.affiliation: National Center for Clinical Laboratories, Beijing Hospital, Beijing, China.
authors.forename: Lunan
authors.initials: L
authors.lastname: Wang
authors.affiliation: National Center for Clinical Laboratories, Beijing Hospital, Beijing, China.
authors.forename: Guigao
authors.initials: G
authors.lastname: Lin
authors.affiliation: National Center for Clinical Laboratories, Beijing Hospital, Beijing, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Sun
authors.affiliation: National Center for Clinical Laboratories, Beijing Hospital, Beijing, China.
authors.forename: Rui
authors.initials: R
authors.lastname: Zhang
authors.affiliation: National Center for Clinical Laboratories, Beijing Hospital, Beijing, China.
authors.forename: Jiehong
authors.initials: J
authors.lastname: Xie
authors.affiliation: National Center for Clinical Laboratories, Beijing Hospital, Beijing, China; Graduate School, Peking Union Medical College, Chinese Academy of Medical Science, Beijing, China.
authors.forename: Jinming
authors.initials: J
authors.lastname: Li
mesh_terms: D000913:Antibodies, Protozoan / Q000032:analysis; D002681:China; D019411:Clinical Laboratory Techniques / Q000379:methods* / Q000592:standards / Q000639:trends; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods / Q000639:trends; D005455:Fluorescent Antibody Technique / Q000379:methods / Q000639:trends; D006790:Host-Parasite Interactions / Q000276:immunology; D006801:Humans; D007074:Immunoglobulin G / Q000032:analysis; D007075:Immunoglobulin M / Q000032:analysis; D007753:Laboratories / Q000592:standards / Q000706:statistics & numerical data; D059021:Laboratory Proficiency Testing; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000379:methods* / Q000592:standards / Q000639:trends; D014122:Toxoplasma / Q000276:immunology* / Q000502:physiology; D014123:Toxoplasmosis / Q000175:diagnosis / Q000276:immunology* / Q000469:parasitology
chemical_list: D000913:Antibodies, Protozoan; D007074:Immunoglobulin G; D007075:Immunoglobulin M