Drivers of individual and temporal variation in host infectiousness: a bird-specific Borrelia as a model system.

A crucial factor to predict the persistence and spread of infections in natural systems (and potential spill-over to humans) is the capacity of so-called reservoir hosts to maintain the infection and transmit it to others. This is known to vary greatly between species, but also within species and through time, although this part of the variation is often less well understood. In this proposal we focus on between- and within-individual variation in infectiousness in a natural population, using a bird-tick-Borrelia system as model. Great tits are among the most important reservoirs of Borrelia garinii, one of the main causal agents of Lyme disease. We will study how the capacity of birds to transmit these bacteria to feeding ticks varies between individuals, how it varies through the annual cycle, and whether stressful episodes may reactivate infections in birds that previously were not infective. We will do this in a well-studied population where we can repeatedly test the infectiousness of the same individuals and relate this to their age, sex, condition and other factors. We will also keep a small number of birds in captivity to study year-round variation in infectiousness in standard conditions. We will challenge birds with moderate stress levels of ecological relevance (e.g. variation in food quality, or brood size). Ultimately we will study how temporal and individual variation affects the basic reproduction number R0 of the infection in nature.

Keywords:INFECTION ECOLOGY, BORRELIA, BIRD POPULATIONS

Disciplines:Animal ecology, Infectious diseases, Parasitology

Project type:Collaboration project