Discussion

Fasciola hepatica, the common liver fluke, is an important cause of disease in sheep and cattle. Sub-clinical infections have a significant impact on productivity, reducing daily live weight gain and milk yield. Prevalence of infection appears to be increasing; climate change, increased animal movements and changes in farming practices have all been suggested as possible reasons for this increase. Control of fluke relies almost exclusively on the use of flukicides and resistance to triclabendazole, the only product active against pathogenic juvenile parasites, is evident. Over the past 10 years we have been using different modeling approaches to develop improved advice on control of fasciolosis for farmers. From a non-modeler’s perspective, I will highlight advances we have made and identify those gaps that are still to be filled. I will demonstrate how we have identified climatic, geographical and topographical factors that explain the spatial distribution of fluke in England and Wales and discuss our current understanding of risk factors at a farm level. I will show how future predicted climate may impact on fluke prevalence and disease incidence and finally I will describe how models can inform vaccine design.