title: Predictive Factors for HIV Seroconversion Among Individuals Attending a Specialized Center After an HIV Risk Exposure: A Case-Control Study.
abstract: To better target our current prevention strategies, we assessed factors associated with HIV seroconversion in individuals attending a specialized center after a risk exposure.
  
  
  
  We studied individuals from an HIV Unit's contact risk cohort at a tertiary care hospital in Barcelona, Spain, between 2003 and 2013 and performed a retrospective matched case-control study. Cases were individuals who seroconverted to HIV after at least 3 months since first follow-up visit for a contracting risk. Controls were HIV-negative individuals from the same cohort. Demographics and behavior variables were studied and compared using a McNemar test assessing factors associated with seroconversion. Univariate analysis and binary logistic regression were performed to develop a model for predicting probability of HIV seroconversion. We also evaluated sensitivity and specificity of our model and an area under Receiver Operating Characteristic (ROC) curve was estimated.
  
  
  
  Sixty-nine (2.2%) individuals seroconverted after a median (interquartile range) of 24 (9-34) months since last follow-up. Seroconverters were predominantly male (96%) and men who have sex with men (MSM) (94%). No differences were observed regarding risk of exposure. Being MSM [odds ratio (OR) 5.2 (1.4-20.2), p = .01], having a known HIV-positive partner [OR 2.7 (1.2-6.2), p = .02], previous postexposure prophylaxis (PEP) [OR 3.9 (1.0-15.6), p = .05], and having previous sexually transmitted infections (STIs) [OR 4.6 (1.9-10.9), p = .001] were the factors independently associated with HIV seroconversion. The sensitivity and specificity of our model were 64.06% and 73.53%, respectively, and the area under ROC curve was 0.777.
  
  
  
  HIV seroconversions were observed frequently between individuals attending a specialized center because of a risk exposure. Being MSM, having had previous PEP, an HIV-positive sexual partner, and previous STI were predictive factors for HIV seroconversion. Closer and longer follow-up and/or pre-exposure prophylaxis should be considered to prevent HIV infections in this high-risk population.
authors.affiliation: 1 HIV Vaccine Development in Catalonia (HIVACAT) , Barcelona, Spain .|2 HIV Unit, Hospital Clínic of Barcelona, University of Barcelona , Barcelona, Spain .
authors.forename: Lorna
authors.initials: L
authors.lastname: Leal
authors.affiliation: 1 HIV Vaccine Development in Catalonia (HIVACAT) , Barcelona, Spain .|2 HIV Unit, Hospital Clínic of Barcelona, University of Barcelona , Barcelona, Spain .
authors.forename: Berta
authors.initials: B
authors.lastname: Torres
authors.affiliation: 1 HIV Vaccine Development in Catalonia (HIVACAT) , Barcelona, Spain .|2 HIV Unit, Hospital Clínic of Barcelona, University of Barcelona , Barcelona, Spain .
authors.forename: Agathe
authors.initials: A
authors.lastname: León
authors.affiliation: 1 HIV Vaccine Development in Catalonia (HIVACAT) , Barcelona, Spain .|2 HIV Unit, Hospital Clínic of Barcelona, University of Barcelona , Barcelona, Spain .
authors.forename: Constanza
authors.initials: C
authors.lastname: Lucero
authors.affiliation: 1 HIV Vaccine Development in Catalonia (HIVACAT) , Barcelona, Spain .|2 HIV Unit, Hospital Clínic of Barcelona, University of Barcelona , Barcelona, Spain .
authors.forename: Alexy
authors.initials: A
authors.lastname: Inciarte
authors.affiliation: 1 HIV Vaccine Development in Catalonia (HIVACAT) , Barcelona, Spain .|2 HIV Unit, Hospital Clínic of Barcelona, University of Barcelona , Barcelona, Spain .
authors.forename: Vicens
authors.initials: V
authors.lastname: Diaz-Brito
authors.affiliation: 2 HIV Unit, Hospital Clínic of Barcelona, University of Barcelona , Barcelona, Spain .
authors.forename: Elisa
authors.initials: E
authors.lastname: de Lazzari
authors.affiliation: 1 HIV Vaccine Development in Catalonia (HIVACAT) , Barcelona, Spain .|2 HIV Unit, Hospital Clínic of Barcelona, University of Barcelona , Barcelona, Spain .
authors.forename: José María
authors.initials: JM
authors.lastname: Gatell
authors.affiliation: 1 HIV Vaccine Development in Catalonia (HIVACAT) , Barcelona, Spain .|2 HIV Unit, Hospital Clínic of Barcelona, University of Barcelona , Barcelona, Spain .
authors.forename: Felipe
authors.initials: F
authors.lastname: García
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D003661:Decision Support Techniques; D005260:Female; D006679:HIV Seropositivity; D006801:Humans; D008297:Male; D010044:Outpatient Clinics, Hospital; D012189:Retrospective Studies; D012307:Risk Factors; D012680:Sensitivity and Specificity; D013030:Spain; D062606:Tertiary Care Centers
keywords: men who have sex with men; post-exposure prophylaxis; risk behavior; seroconversion