To develop methods for estimating the incidence of HIV-1 infection among adults from age-specific prevalence data derived in stable endemic conditions.
Two methods are proposed.
The first method is the Cumulative Incidence and Survival Method which treats HIV-1 prevalence at any given age as the cumulative incidence of new infections at each preceding age, adjusted for mortality.
A model for age-specific incidence is fitted to the data using maximum likelihood techniques.
The other method is the Constant Prevalence Method whereby the incidence of new infections within a time interval (t-r, t) is calculated as the difference, after adjusting for mortality, between observed prevalence levels at two successive age intervals, whose mean ages are r years apart.
The two methods were applied to data from Kampala, Uganda.
Plausible estimates of age-specific and cumulative HIV-1 incidence were obtained from each of the methods.
Estimates of HIV-1 incidence are sensitive to assumptions regarding the length of the survival period after infection and the stability of the epidemic.
Reasonable estimates of HIV-1 incidence can be obtained from prevalence data derived in near-stable conditions.
With the Constant Prevalence Method, these conditions may be relaxed if large sample sizes are available and age-reporting is good.
The methods proposed could be used in the design and implementation of HIV-1 prevention trials. (...)
Mots-clés Pascal : SIDA, Virose, Infection, Virus HIV1, Virus immunodéficience humaine, Lentivirinae, Retroviridae, Virus, Méthode, Estimation, Modèle mathématique, Evolution, Incidence, Adulte, Homme, Prévalence, Epidémie, Immunopathologie, Immunodéficit, Epidémiologie, Statistique
Mots-clés Pascal anglais : AIDS, Viral disease, Infection, HIV-1 virus, Human immunodeficiency virus, Lentivirinae, Retroviridae, Virus, Method, Estimation, Mathematical model, Evolution, Incidence, Adult, Human, Prevalence, Epidemic, Immunopathology, Immune deficiency, Epidemiology, Statistics
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 97-0036201
Code Inist : 002B06D01. Création : 21/05/1997.