13 research outputs found
Noise, nonlinearity and seasonality: the epidemics of whooping cough revisited
Understanding the mechanisms that generate oscillations in the incidence of
childhood infectious diseases has preoccupied epidemiologists and population
ecologists for nearly two centuries. This body of work has generated simple yet
powerful explanations for the epidemics of measles and chickenpox, while the
dynamics of other infectious diseases, such as whooping cough, have proved more
challenging to decipher. A number of authors have, in recent years, proposed
that the noisy and somewhat irregular epidemics of whooping cough may arise due
to stochasticity and its interaction with nonlinearity in transmission and
seasonal variation in contact rates. The reason underlying the susceptibility of
whooping cough dynamics to noise and the precise nature of its transient
dynamics remain poorly understood. Here we use household data on the incubation
period in order to parametrize more realistic distributions of the latent and
infectious periods. We demonstrate that previously reported phenomena result
from transients following the interaction between the stable annual attractor
and unstable multiennial solutions