title: Comparison of methods for the detection of treponema pallidum in lesions of early syphilis.
abstract: BACKGROUND
  The clinical diagnosis of primary and secondary syphilis can be difficult because of the wide variability of lesions. The available laboratory tests (dark-field microscopy and direct fluorescent antibody) require specialized microscopes and skilled technicians, and serologic tests are insensitive in early infection.
  
  
  METHODS
  Dark-field microscopy and monoclonal antibody staining were compared to a new solid-phase enzyme-linked immunosorbent assay (Visuwell test) for detection of T. pallidum in lesion exudate of 188 patients with genital lesions.
  
  
  RESULTS
  Sixty-four patients (34%) had lesions of early syphilis diagnosed by either dark-field, monoclonal antibody staining, or both. The Visuwell test and dark-field examination were positive in 52 (81.3%) and 55 (85.9%) of the 64 patients, respectively, whereas the monoclonal antibody staining technique demonstrated the presence of T. pallidum in 59 (92.2%) of the 64 patients. The Visuwell test gave a negative result in 111 of 124 patients who had negative dark-field and direct fluorescent antibody test results (89.5% specificity).
  
  
  CONCLUSIONS
  The Visuwell test is an alternative method for evaluating genital ulcers but is less sensitive and specific than existing tests.
authors.affiliation: Department of Medicine, State University of New York Health Science Center, Brooklyn 11203, USA.
authors.forename: M C
authors.initials: MC
authors.lastname: Cummings
authors.forename: S A
authors.initials: SA
authors.lastname: Lukehart
authors.forename: C
authors.initials: C
authors.lastname: Marra
authors.forename: B L
authors.initials: BL
authors.lastname: Smith
authors.forename: J
authors.initials: J
authors.lastname: Shaffer
authors.forename: L R
authors.initials: LR
authors.lastname: Demeo
authors.forename: C
authors.initials: C
authors.lastname: Castro
authors.forename: W M
authors.initials: WM
authors.lastname: McCormack
mesh_terms: D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods*; D019085:Fluorescent Antibody Technique, Direct / Q000379:methods; D006801:Humans; D008853:Microscopy / Q000379:methods; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013591:Syphilis, Cutaneous / Q000175:diagnosis* / Q000382:microbiology*; D013997:Time Factors