title: The incubation period of acute retroviral syndrome as a multistep process: a parametric survival analysis.
abstract: A long duration of acute retroviral syndrome (ARS) and a short incubation of ARS (IncARS) are independent predictors of a fast progression to AIDS. The first objective of this study was to validate previous estimates of IncARS by comparing durations between health care workers (HCWs) accidentally infected by HIV and individuals infected by other routes (non-health care workers [N-HCWs]). The second objective was to use parametric survival models to generate hypotheses on various steps occurring during the IncARS. Data from a prospective cohort of patients with documented ARS and from individuals with ARS as the result of accidental exposure to HIV were analyzed. Nonparametric and parametric survival models were used to describe the incubation of ARS. No differences were found for the median IncARS between 34 HCWs (21.5 days) and 70 N-HCWs (21.5 days) (log-rank test, P = 0.72). According to survival models, IncARS can be modeled with a gamma and/or lognormal model with means of 26.4 days and 26.7 days, respectively. The gamma model suggests that 3 sequential stages are present during the IncARS, which is compatible with basic science investigations identifying crossing of the epithelial barrier by the virus, the virus-host cell interactions, and the viral systemic dissemination.
authors.affiliation: Laboratory of Epidemiology and Public Health, INSERM U271, Université Claude Bernard, and Epidemiology Unit, Edouard Herriot Hospital, Lyon, France. philipva@lyon-sud.univ-lyon1.fr
authors.forename: Philippe
authors.initials: P
authors.lastname: Vanhems
authors.forename: Nicolas
authors.initials: N
authors.lastname: Voirin
authors.forename: Pierre
authors.initials: P
authors.lastname: Philippe
authors.forename: Bernard
authors.initials: B
authors.lastname: Hirschel
authors.forename: Joelle
authors.initials: J
authors.lastname: Brassard
authors.forename: Andrew
authors.initials: A
authors.lastname: Carr
authors.forename: David A
authors.initials: DA
authors.lastname: Cooper
authors.forename: Luc
authors.initials: L
authors.lastname: Perrin
authors.forename: Robert
authors.initials: R
authors.lastname: Allard
mesh_terms: D015331:Cohort Studies; D018450:Disease Progression; D005260:Female; D015658:HIV Infections / Q000175:diagnosis* / Q000635:transmission; D006801:Humans; D017758:Infectious Disease Transmission, Patient-to-Professional; D008297:Male; D011237:Predictive Value of Tests; D011379:Prognosis; D016016:Proportional Hazards Models; D016019:Survival Analysis; D013577:Syndrome; D013997:Time Factors