To effectively control an outbreak, it must first be clear how a virus or bacteria is spread. How long do infected animals continue to excrete measurable levels of pathogens, how quickly do other animals become infected and what is the infection route?
These questions can be investigated on a small scale in a transmission experiment, in which a number of deliberately infected animals are brought into contact with non-infected animals. By periodically testing the animals (temperature, swabs, blood samples), much information on the progression of the disease can be acquired, and for instance on the effectiveness of a vaccine. This information is crucial to predict the effect of control strategies.
The epidemiology group is involved with the statistical aspects of such transmission experiments from beginning to end. By carefully considering the design of the experiment beforehand, as much information as possible can be obtained afterwards during the analysis, while using the smallest possible number of animals.