title: Late presentation to HIV testing is overestimated when based on the consensus definition.
abstract: OBJECTIVE
  In 2011, a consensus was reached defining "late presenters" (LPs) as individuals presenting for care with a CD4 count < 350 cells/μL or with an AIDS-defining event, regardless of CD4 count. However, a transient low CD4 count is not uncommon in recent infections. The objective of this study was to investigate how measurements of late presentation change if the clinical stage at the time of diagnosis is taken into account.
  
  
  METHODS
  Case surveillance data for newly diagnosed patients in Belgium in 1998-2012 were analysed, including CD4 count at diagnosis, the presence of AIDS-defining events, and recent infections (< 6 months) as reported by clinicians in the case of acute illness or a recent negative test. First, proportions of LPs were calculated according to the consensus definition. Secondly, LPs were reclassified as "nonlate" if infections were reported as recent.
  
  
  RESULTS
  A total of 7949 HIV diagnoses were included in the study. Recent infections were increasingly reported over time, accounting for 8.2% of new infections in 1998 and 37.5% in 2012. The consideration of clinical stage significantly modified the proportion of LPs: 18.2% of men who have sex with men (MSM) diagnosed in 2012 would be classified as LPs instead of 30.9% using the consensus definition (P < 0.001). The proportion of patients misclassified as LPs increased significantly over time: 5% in MSM in 1998 vs. 41% in 2012.
  
  
  CONCLUSIONS
  This study suggests that low CD4 counts in recent infections may lead to overestimation of late presentation when applying the consensus definition. The impact of transient CD4 count on late presentation estimates should be assessed and, if relevant, the introduction of clinical stage in the definition of late presentation should be considered.
authors.affiliation: Scientific Institute of Public Health, Brussels, Belgium.
authors.forename: A
authors.initials: A
authors.lastname: Sasse
authors.affiliation: Instituut Tropische Geneeskunde Antwerpen, Antwerp, Belgium.
authors.forename: E
authors.initials: E
authors.lastname: Florence
authors.affiliation: European Centre for Disease Prevention and Control, Stockholm, Sweden.
authors.forename: A
authors.initials: A
authors.lastname: Pharris
authors.affiliation: CHU Saint-Pierre, Brussels, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: De Wit
authors.affiliation: Universitair Ziekenhuis Brussel, Brussels, Belgium.
authors.forename: P
authors.initials: P
authors.lastname: Lacor
authors.affiliation: Scientific Institute of Public Health, Brussels, Belgium.
authors.forename: D
authors.initials: D
authors.lastname: Van Beckhoven
authors.affiliation: Scientific Institute of Public Health, Brussels, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Deblonde
authors.affiliation: Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: M-L
authors.initials: ML
authors.lastname: Delforge
authors.affiliation: Instituut Tropische Geneeskunde Antwerpen, Antwerp, Belgium.
authors.forename: K
authors.initials: K
authors.lastname: Fransen
authors.affiliation: Hôpital Erasme, Université Libre de Bruxelles, Brussels, Belgium.
authors.forename: J-C
authors.initials: JC
authors.lastname: Goffard
authors.affiliation: CHU de Charleroi, Charleroi, Belgium.
authors.forename: J-C
authors.initials: JC
authors.lastname: Legrand
authors.affiliation: CHU de Liège, Liege, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Moutschen
authors.affiliation: Universitair Ziekenhuis Brussel, Brussels, Belgium.
authors.forename: D
authors.initials: D
authors.lastname: Piérard
authors.affiliation: Université Catholique de Louvain, Brussels, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Ruelle
authors.affiliation: CHU de Liège, Liege, Belgium.
authors.forename: D
authors.initials: D
authors.lastname: Vaira
authors.affiliation: Cliniques Universitaires Saint-Luc, Brussels, Belgium.
authors.forename: B
authors.initials: B
authors.lastname: Vandercam
authors.affiliation: Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: M
authors.initials: M
authors.lastname: Van Ranst
authors.affiliation: Katholieke Universiteit Leuven, Leuven, Belgium.
authors.forename: E
authors.initials: E
authors.lastname: Van Wijngaerden
authors.affiliation: Universitair Ziekenhuis Gent, Ghent, Belgium.
authors.forename: L
authors.initials: L
authors.lastname: Vandekerckhove
authors.affiliation: Universiteit Gent, Ghent, Belgium.
authors.forename: C
authors.initials: C
authors.lastname: Verhofstede
mesh_terms: D001530:Belgium / Q000453:epidemiology; D018791:CD4 Lymphocyte Count; D032921:Consensus; D057210:Delayed Diagnosis / Q000706:statistics & numerical data; D015658:HIV Infections / Q000175:diagnosis* / Q000453:epidemiology* / Q000473:pathology; D018451:Homosexuality, Male / Q000706:statistics & numerical data; D006801:Humans; D008297:Male; D012307:Risk Factors
keywords: AIDS; HIV; consensus definition; late diagnosis; late presentation; men who have sex with men; testing