title: The development and validation of dried blood spots for external quality assurance of syphilis serology.
abstract: BACKGROUND
  Syphilis causes up to 1,500,000 congenital syphilis cases annually. These could be prevented if all pregnant women were screened, and those with syphilis treated with a single dose of penicillin before 28 weeks gestation. In recent years, rapid point-of-care tests have allowed greater access to syphilis screening, especially in rural or remote areas, but the lack of quality assurance of rapid testing has been a concern. We determined the feasibility of using dried blood spots (DBS) as specimens for quality assurance of syphilis serological assays.
  
  
  METHODS
  We developed DBS extraction protocols for use with Treponema pallidum particle agglutination assay (TPPA), Treponema pallidum haemagglutination assay (TPHA) and an enzyme immunoassay (EIA) and compared the results with those using matching plasma samples from the same patient.
  
  
  RESULTS
  Since DBS samples showed poor performance with TPHA and EIA (TPHA sensitivity was 50.5% (95% confidence interval: 39.9-61.2%) and EIA specificity was 50.4% (95% CI: 43.7-57.1%), only the DBS TPPA was used in the final evaluation. DBS TPPA showed an sensitivity of 95.5% (95% CI: 91.3-98.0%) and a specificity of 99.0% (95% CI: 98.1-99.5%) compared to TPPA using plasma samples as a reference.
  
  
  CONCLUSIONS
  DBS samples can be recommended for use with TPPA, and may be of value for external quality assurance of point-of-care syphilis testing.
authors: Leiden Cytology and Pathology Laboratory, Leiden, The Netherlands. Pieter.smit@lshtm.ac.uk
authors: Pieter W
authors: PW
authors: Smit
authors: Thomas
authors: T
authors: van der Vlis
authors: David
authors: D
authors: Mabey
authors: John
authors: J
authors: Changalucha
authors: Julius
authors: J
authors: Mngara
authors: Benjamin D
authors: BD
authors: Clark
authors: Aura
authors: A
authors: Andreasen
authors: Jim
authors: J
authors: Todd
authors: Mark
authors: M
authors: Urassa
authors: Basia
authors: B
authors: Zaba
authors: Rosanna W
authors: RW
authors: Peeling
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000372:Agglutination Tests / Q000379:methods / Q000592:standards; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011247:Pregnancy; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013588:Syphilis Serodiagnosis / Q000379:methods* / Q000592:standards*; D014210:Treponema pallidum / Q000276:immunology*; D055815:Young Adult
chemical_list: D000907:Antibodies, Bacterial