title: Frequency and Spectrum of Unexpected Clinical Manifestations of Primary HIV-1 Infection.
abstract: BACKGROUND
  Prospectively and systematically collected data on frequency and spectrum of unexpected clinical manifestations during primary human immunodeficiency virus (HIV) infection (PHI) have not been published.
  
  
  METHODS
  We prospectively enrolled 290 patients with documented PHI in the Zurich Primary HIV Infection Study. Typical acute retroviral syndrome (ARS) was defined as fever plus at least 1 symptom or sign typically considered to be associated with ARS; in absence of fever, presence of 2 or more ARS symptoms or signs. Atypical ARS was defined as lack of symptoms or signs, a single symptom or sign only and absence of fever, presence of symptoms or signs that are not considered typically associated with ARS, or occurrence of an opportunistic disease. Time to diagnosis was calculated based on estimated date of infection and first positive HIV test.
  
  
  RESULTS
  We analyzed 290 patients (271 males). PHI manifested with typical ARS in 202 (70%) and with atypical ARS in 88 (30%) patients. Patients with atypical ARS were hospitalized 4 times more often compared with typical ARS (43% vs 11%; P < .001). The gastrointestinal tract was the most frequent organ system affected in patients with atypical manifestations. Only in 112 (38%) patients was HIV infection suspected during the first medical attendance. Patients with typical ARS were diagnosed slightly earlier compared with atypical ARS, but this difference was not significant (P = .3).
  
  
  CONCLUSIONS
  Unexpected clinical presentations occurred in a large fraction of patients with PHI and were associated with substantial morbidity. Universal HIV testing may be mandatory in high-risk groups.
authors.affiliation: Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich Institute of Medical Virology, University of Zurich, Switzerland.
authors.forename: Dominique L
authors.initials: DL
authors.lastname: Braun
authors.affiliation: Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich Institute of Medical Virology, University of Zurich, Switzerland.
authors.forename: Roger D
authors.initials: RD
authors.lastname: Kouyos
authors.affiliation: Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich.
authors.forename: Belinda
authors.initials: B
authors.lastname: Balmer
authors.affiliation: Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich.
authors.forename: Christina
authors.initials: C
authors.lastname: Grube
authors.affiliation: Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich.
authors.forename: Rainer
authors.initials: R
authors.lastname: Weber
authors.affiliation: Division of Infectious Diseases and Hospital Epidemiology, University Hospital Zurich Institute of Medical Virology, University of Zurich, Switzerland.
authors.forename: Huldrych F
authors.initials: HF
authors.lastname: Günthard
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D005260:Female; D015658:HIV Infections / Q000175:diagnosis* / Q000453:epidemiology / Q000473:pathology*; D015497:HIV-1 / Q000302:isolation & purification*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011446:Prospective Studies; D013557:Switzerland / Q000453:epidemiology; D055815:Young Adult
keywords: ARS; acute HIV-infection; acute retroviral syndrome; atypical clinical presentation; primary HIV-1 infection