Linking Parasite, People and Places: The Food Networks of Liver Fluke Infection

One of the top ten foodborne parasitic infections of global concern is human infection of liver fluke through the consumption of raw or undercooked freshwater fish. This article examines the influences of human–environmental interactions of raw fish sharing and procurement connections on the geographic variation in liver fluke infection. We first discuss the networks embedded in the parasite life cycle that propagates disease transmission. Then, we collect 820 questionnaires from three provinces in northeast Thailand to visualize their fish-sharing and sharing-procurement networks, analyze how the connectivity differences in these networks might be linked to participants’ consumption behaviors and environmental settings, and determine how all these together affect liver fluke infection risks. The results show that infection was positively associated with procuring fish from ponds, but negatively associated with procuring fish from rivers. Incorporating fish procurement sites substantially increases network connectivity, reinforcing the human connection to key fish sources as a potential risk factor for infection. The consideration of the connections between human, disease hosts, and the environment, compared to the previously human-centric approach of deworming, offers new insights for public health intervention.