Figure 3. Blueprint illustrating environmental factors known or suspected to be associated with transmission of Opisthorchis viverrini.

Regional environmental change, which is influenced significantly by population growth, resource consumption, economic development projects, agriculture intensification and waste generation, plays an important role in the emergence of infectious disease in general especially in tropical developing regions. In the case of Opisthorchis viverrini (Ov), although the importance of these broader determinants have been evoked more than a decade ago [2], formal research acknowledging their significance in modulating transmission dynamics and disease manifestation has just begun. Of particular concern in the case of Ov is the unprecedented land use and transformation of resource production (urbanization, agricultural expansion and intensification, and natural habitat alteration) that has intensified during the last decade in the region, and that is increasingly recognized to have produced changes in ecological systems, notably in landscapes and, in turn, their natural communities and ultimately in their parasites, animal host, and human populations. Thus the entire host-parasite dynamics is being modified, including pattern of exposure and susceptibility to disease. Designing research and interventions that integrate these broad scale determinants of transmission and their interactions is key for the proper contextualization of Opisthorchis viverrini control. Overarching systemic factors related to public health infrastructure and climate variability, and their interactions with regional environmental change, also contribute significantly to disease emergence although more diffusely.