The genetic propensity of animals to transmit diseases affects survival in populations during epidemics, study shows. Image Turbot fish Survival in animal populations during an epidemic is partly determined by the genetic propensity of individual animals to transmit it to others, research shows. It is well known that genetic differences in disease resistance affect mortality rates in populations during an epidemic. A genetic study led by scientists at the Roslin Institute, in collaboration with researchers in Spain, found that mortality rates also depend on genetic differences in endurance – the propensity of a sick animal to survive infection – and infectivity – the propensity of an infected animal to transmit the disease to others. This is the first time scientists have provided evidence of genetic variation in infectivity of infected animals. Important aquaculture disease Scientists looked at how long it took for turbot to become infected and ill with – or die of – scuticociliatosis after being exposed to infected fish. Scuticociliatosis is one of the most important diseases in marine aquaculture worldwide. They used novel experimental designs and statistical modelling to investigate whether differences in the genes determined endurance, infectivity and resistance of infected fish and demonstrated how this contributed to survival. Understanding and controlling epidemics This study is the first existing evidence that animals differ genetically not only in their resistance to disease, but also in their ability to transmit disease. Our infection model in fish shows that genetic variation in infectivity of infected animals, in addition to variation in resistance and endurance, affects survival in populations. These results have important implications for understanding and controlling epidemics. Professor Andrea WilsonPrincipal Investigator, the Roslin Institute The study is published in the journal Scientific Reports and has been funded by the EU FP7 Framework project Fishboost and the UK Government’s Biotechnology and Biological Sciences Research Council. ** The Roslin Institute is part of the University of Edinburgh’s Royal (Dick) School of Veterinary Studies. ** Relevant links Scientific publication Aquaculture genetics consortium set to tackle industry challenges Genetic basis of host resistance Prof. Andrea Wilson on the genetics of disease and behaviour Fishboost
