The epidemiology of hepatitis A in countries across the world is changing due to improvements in hygiene and living conditions which reduce the transmissibility of the infection.
A mathematical model is formulated to describe the changes in incidence of a directly transmitted infection produced by a long term decline in its transmissibility.
The basic reproduction number, the parameter describing transmissibility, is considered as a function of time.
The relationship between the basic reproduction number and the force of infection is derived.
Theoretical examples demonstrate that a decline in transmissibility results in an initial decline in the force of infection, but that this may be followed by a substantial resurgence.
Resurgences may be possible after several decades of declining incidence, and are most marked following a rapid decline.
Countries which have experienced a rapid decline in the incidence of hepatitis A may be at risk of a resurgence.
More detailed mathematical models, informed with data from regular age-stratified serological surveys, should provide the basis for decisions on vaccination policy.
Mots-clés Pascal : Hépatite virale A, Virose, Infection, Modèle mathématique, Transmission, Epidémiologie, Homme, Appareil digestif pathologie, Foie pathologie
Mots-clés Pascal anglais : Viral hepatitis A, Viral disease, Infection, Mathematical model, Transmission, Epidemiology, Human, Digestive diseases, Hepatic disease
Notice produite par :
Inist-CNRS - Institut de l'Information Scientifique et Technique
Cote : 96-0390177
Code Inist : 002B05C02G. Création : 10/04/1997.