title: Diagnosis of treponemal co-infection in HIV-infected West Africans.
abstract: OBJECTIVE
  To evaluate the performance of two enzyme immunoassays (EIA), Murex and ICE, and the Determine TP point-of-care test (POCT) in diagnosing treponemal infection (syphilis or yaws) in patients attending a large HIV clinic in Ghana; to determine the prevalence of treponemal co-infections; and to characterise demographic and clinical features of patients with infection.
  
  
  METHODS
  Samples were tested with EIAs and rapid plasma reagin (RPR), then POCT and reference assays for Treponema pallidum to determine prevalence of active and past infection. Sensitivity and specificity of each assay were calculated and demographic and clinical characteristics of patients compared. Data were collected from case notes of patients retrospectively.
  
  
  RESULTS
  Overall, 45/284 patient samples (14.8%, 95% CI, 11.1-19.4%) were Treponema pallidum particle agglutination (TPPA) positive, and of these, 27 (64.3%) were RPR positive and 4 (8.9%) were treponemal IgM positive. Both EIAs and Determine TP POCT showed high sensitivities and specificities for identifying infection although RPR was less reliable. Clinical features of syphilis or yaws were rarely identified in TPPA-positive patients suggesting most had previous or late latent infection. Treatment of various intercurrent infections using short courses of antibiotics active against T. pallidum was common in the clinic.
  
  
  CONCLUSIONS
  A high proportion of this HIV-infected cohort showed evidence of treponemal infection. Both EIAs as well as the POCT were practical and effective at diagnosing treponemal co-infection in this setting. RPR alone was unreliable at identifying active treponemal co-infection, however might be useful in some settings where treponemal-specific assays are unaffordable.
authors.affiliation: The James Cook University Hospital, Middlesbrough, UK  Komfo Anokye Teaching Hospital, Kumasi, Ghana  Health Protection Agency South West Regional Laboratory, Bristol, UK.
authors.forename: Yaasir
authors.initials: Y
authors.lastname: Mamoojee
authors.forename: Grace
authors.initials: G
authors.lastname: Tan
authors.forename: Sandra
authors.initials: S
authors.lastname: Gittins
authors.forename: Stephen
authors.initials: S
authors.lastname: Sarfo
authors.forename: Lisa
authors.initials: L
authors.lastname: Stephenson
authors.forename: David
authors.initials: D
authors.lastname: Carrington
authors.forename: George
authors.initials: G
authors.lastname: Bedu-Addo
authors.forename: Richard
authors.initials: R
authors.lastname: Phillips
authors.forename: Lambert T
authors.initials: LT
authors.lastname: Appiah
authors.forename: David
authors.initials: D
authors.lastname: Chadwick
mesh_terms: D000328:Adult; D015897:Comorbidity; D003430:Cross-Sectional Studies; D005260:Female; D005869:Ghana / Q000453:epidemiology; D015658:HIV Infections / Q000453:epidemiology*; D006801:Humans; D008297:Male; D019095:Point-of-Care Systems; D012680:Sensitivity and Specificity; D016036:Seroepidemiologic Studies; D012698:Serologic Tests / Q000379:methods*; D013588:Syphilis Serodiagnosis / Q000379:methods; D014211:Treponemal Infections / Q000175:diagnosis* / Q000453:epidemiology*