Transmission risk assessment of invasive fluke Fascioloides magna using GIS-modelling and multicriteria analysis methods

The combination of multicriteria analysis (MCA), particularly analytic hierarchy process (AHP) and geographic information system (GIS) were applied for transmission risk assessment of Fascioloides magna (Trematoda; Fasciolidae) in south-western Slovakia. Based on the details on F. magna life cycle, the following risk factors (RF) of parasite transmission were determined: intermediate (RF_IH) and final hosts (RF_FH) (biological factors), annual precipitation (RF_AP), land use (RF_LU), flooded area (RF_FA), and annual mean air temperature (RF_AT) (environmental factors). Two types of risk analyses were modelled: (1) potential risk analysis was focused on the determination of the potential risk of parasite transmission into novel territories (data on F. magna occurrence were excluded); (2) actual risk analysis considered also the summary data on F. magna occurrence in the model region (risk factor parasite occurrence RF_PO included in the analysis). The results of the potential risk analysis provided novel distribution pattern and revealed new geographical area as the potential risk zone of F. magna occurrence. Although the actual risk analysis revealed all four risk zones of F. magna transmission (acceptable, moderate, undesirable and unacceptable), its outputs were significantly affected by the data on parasite occurrence what reduced the informative value of the actual transmission risk assessment.