title: An evidence based approach to testing for antibody to herpes simplex virus type 2.
abstract: OBJECTIVE
  To establish whether a simple risk scoring system, based on limited information, can reflect the variation in HSV-2 prevalence in a population, and whether a common system can be used across settings. To establish whether knowledge of a patient's score can aid the interpretation of the result from one of the commercial type specific assays.
  
  
  METHODS
  Four previous cross sectional studies are considered, with HSV-2 antibody results by western blot or type specific ELISA tests. The clinical settings were a blood donor centre (1359 participants) and STD clinic (808 participants), London, United Kingdom, an antenatal clinic, Sydney, Australia (2317 participants), and a family medical centre, Seattle, United States (478 participants). We determined the factors associated with HSV-2 prevalence, the similarity of associations across settings, and the variation in HSV-2 prevalence by risk score.
  
  
  RESULTS
  A simple scoring captured much variation in HSV-2 prevalence in each population-for example, for London blood donors, scoring based on sex, age, and number of lifetime partners, prevalence varied from 0.7% (95% CI 0.1 to 2.0) to 47.3% (37.9 to 56.6) across five risk groups. For number of lifetime partners, and sex, the association with HSV-2 varied significantly across studies.
  
  
  CONCLUSIONS
  A scoring system can aid test interpretation-for example, in London blood donors the post-test probability of infection following a positive result varies from around 25% to 98% across risk groups for a typical type specific assay. Further work could address whether this theoretical benefit can be realised in practice. A common risk scoring probably could not be used across settings.
authors.affiliation: Department of Sexually Transmitted Diseases, Royal Free and University College Medical School, Mortimer Market Centre, off Capper Street, London WC1E 6AU, UK. acopas@gum.ucl.ac.uk
authors.forename: A J
authors.initials: AJ
authors.lastname: Copas
authors.forename: F M
authors.initials: FM
authors.lastname: Cowan
authors.forename: A L
authors.initials: AL
authors.lastname: Cunningham
authors.forename: A
authors.initials: A
authors.lastname: Mindel
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D000914:Antibodies, Viral / Q000032:analysis*; D015153:Blotting, Western; D003430:Cross-Sectional Studies; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006558:Herpes Genitalis / Q000175:diagnosis* / Q000276:immunology / Q000821:virology; D018258:Herpesvirus 2, Human / Q000276:immunology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D018570:Risk Assessment; D012307:Risk Factors; D012747:Sexual Partners
chemical_list: D000914:Antibodies, Viral