Validation of an interactive map assessing the potential spread of Galba truncatula as intermediate host of Fasciola hepatica in Switzerland

Abstract

Bovine fasciolosis, caused by <em>Fasciola hepatica</em>, is widespread in Switzerland. The risk regions were modelled in 2008 by an interactive map, showing the monthly potential risk of transmission of <em>F. hepatica</em> in Switzerland. As this map is based on a mathematical model, the aim of the present study was to evaluate the interactive map by means of a field survey taking different data sources into account. It was found that the interactive map has a sensitivity of 40.7-88.9%, a specificity of 11.4-18.8%, a positive predictive value of 26.7-51.4%, and a negative predictive value of 13.1-83.6%, depending on the source of the data. In conclusion, the grid of the interactive map (100 x 100 m) does not reflect enough detail and the underlying model of the interactive map is lacking transmission data.