%0 Journal Article
%T Converging seasonal prevalence dynamics in experimental epidemics
%A Sandra Lass
%A J¨¹rgen W Hottinger
%A Thomas Fabbro
%A Dieter Ebert
%J BMC Ecology
%D 2011
%I BioMed Central
%R 10.1186/1472-6785-11-14
%X In an outdoor experiment, populations were set up to include the extremes of the prevalence spectrum observed in natural populations: 5% initial prevalence mimicking a newly invading parasite, 100% mimicking a rock pool population founded by infected hosts only, and 50% prevalence which is commonly observed in natural populations in spring. The parasite exhibited similar prevalence changes in all treatments, but seasonal patterns in the 100% treatment differed significantly from those in the 5% and 50% treatments. Populations started with 5% and 50% prevalence exhibited strong and regular seasonality already in the first year. In contrast, the amplitude of changes in the 100% treatment was low throughout the experiment demonstrating the long-lasting effect of initial conditions on prevalence dynamics.Our study shows that the time needed to approach the seasonal changes in prevalence depends strongly on the initial prevalence. Because individual D. magna populations in this rock pool metapopulation are mostly short lived, only few populations might ever reach a point where the initial conditions are not visible anymore.Seasonal changes in prevalence are ubiquitous in infectious diseases of plants, invertebrates and vertebrates [1-7]. Some of the more famous ones are influenza and measles, two of the paradigms for regular seasonal epidemics. Understanding the dynamics of such prevalence patterns has been a major challenge in epidemiology for the last decades. Numerous factors are known to cause and influence seasonal prevalence dynamics. Extrinsic factors affecting prevalence dynamics include physical conditions such as weather as well as community context of the host-parasite system, i.e. interactions with other members of the community [6-13]. Transmission of the influenza virus has been shown to depend on temperature and humidity and to be favoured by dry and cold conditions [14]. Intrinsic factors, inherent properties of the host-parasite system itself, include th
%K Daphnia magna
%K microparasite
%K microsporidium
%K Hamiltosporidium tv£¿rminnensis
%K Octosporea bayeri
%K population density
%U http://www.biomedcentral.com/1472-6785/11/14