Statistical Aspects of Health Monitoring in Rodents

To make a valid diagnosis for specific infections in animals, the sample size has to be calculated based upon the expected prevalence, i.e., the fraction of animals that it is reasonable to assume, that this specific agent will infect in the colony, and the sensitivity of the assay, i.e., how the fraction of the infected animals are likely to become positive in the assay. In smaller colonies, the size of the colony also has an impact on the sample size