title: Prevalence and correlates of unknown HIV infection among patients seeking care in a public hospital emergency department.
abstract: OBJECTIVE
  Screening for human immunodeficiency virus (HIV) infection in the emergency department (ED) has been proposed as an effective approach to increase early HIV diagnosis. To evaluate the potential for the implementation of routine screening, we determined the prevalence of unknown HIV infection among patients being seen in an urban public hospital ED.
  
  
  METHODS
  We conducted a cross-sectional study among patients presenting to the San Francisco General Hospital's ED during March 2007. We reviewed patients' medical records to determine HIV infection status. In patients with unknown or negative HIV-infection status, we tested de-identified remnant blood specimens by HIV-antibody and nucleic-acid assays. We used a sensitive/less sensitive testing algorithm to determine the duration of HIV infection.
  
  
  RESULTS
  During the study period, 1,820 patients had blood collected for clinical evaluation. Of those patients, 146 (8.0%) were known to be HIV-infected. Among the remaining 1,674 patients with unknown HIV-infection status, HIV-infection prevalence was 0.9% (15 of 1,674, 95% confidence interval [CI] 0.55, 1.47). In addition, one case of acute HIV infection (HIV-antibody negative, HIV RNA detected) was identified. Patients with unknown HIV infection vs. those who were uninfected were more likely to be homeless (odds ratio [OR] = 3.89, 95% CI 1.32, 11.45, p<0.05) and 18 to 30 years of age (OR=3.15, 95% CI 1.03, 9.61, p<0.05).
  
  
  CONCLUSIONS
  In a sample of patients visiting a county ED, the relative prevalence of unknown HIV infection (10%) was modest and less than national estimates (25%). Acutely HIV-infected patients might account for a significant proportion of those with unknown HIV infection in an ED setting.
authors.affiliation: Division of Infectious Diseases, Department of Medicine, University of California, San Francisco, CA, USA.
authors.forename: Nicola M
authors.initials: NM
authors.lastname: Zetola
authors.forename: Beth
authors.initials: B
authors.lastname: Kaplan
authors.forename: Teri
authors.initials: T
authors.lastname: Dowling
authors.forename: Trevor
authors.initials: T
authors.lastname: Jensen
authors.forename: Brian
authors.initials: B
authors.lastname: Louie
authors.forename: Mahtab
authors.initials: M
authors.lastname: Shahkarami
authors.forename: Grant
authors.initials: G
authors.lastname: Colfax
authors.forename: Jeffrey D
authors.initials: JD
authors.lastname: Klausner
mesh_terms: D000293:Adolescent; D000328:Adult; D002140:California / Q000453:epidemiology; D003430:Cross-Sectional Studies; D004636:Emergency Service, Hospital / Q000706:statistics & numerical data*; D005260:Female; D015658:HIV Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000276:immunology; D006779:Hospitals, Public; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D010342:Patient Acceptance of Health Care / Q000706:statistics & numerical data*; D012307:Risk Factors; D016036:Seroepidemiologic Studies; D014481:United States / Q000453:epidemiology; D055815:Young Adult