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

Abstract

SummaryThe 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 fi nal hosts (RF FH ) (biological factors), annual precipitation (RF AP ), land use (RF LU ), fl ooded 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 signifi cantly affected by the data on parasite occurrence what reduced the informative value of the actual transmission risk assessment.

The Large American Liver Fluke (Fascioloides magna): A Survivor’s Journey through a Constantly Changing World

“…The relevance of tributary streams of the Danube as potential expansion routes has been confirmed several times. In Slovakia, the Vah/Vág and the Hron/Garam open gates to spread opposite the flow direction [73]. By the Croatian-Hungarian border river Drava, the same phenomenon can be observed [75,76,82,83].…”

“…Exotic aquatic plants can change the flow velocity, the sediment deposition, and the primary production of the ecosystem [129,132], thus changing the living conditions of potential intermediate hosts of trematodes [43]. The extensive agricultural activity as a risk factor for F. magna infection is confirmed [73]. The increased nutrient content of water enhances the growth of pondweeds, which provide food and shelter for snails.…”

“…The first cases were detected in Slovakia by the Hungarian border [69], then a year later on the opposite side of the border river Danube in Hungary [70,71]. This ecosystem provides ideal conditions for continuous spread through the continent by the river's flow direction [3,5,7,72,73].…”

“…Lymnaea) palustris nuttalliana, and Pseudosuccinea columella [3,5,7,11,12]. However, in Europe, only two species-Galba truncatula and Radix labiata/peregra-are confirmed to be able to acquire infection and produce viable cercariae in natural circumstances [5,11,73].…”