Advances, challenges, and applications of laboratory culture of digenean trematode parasites

The development of parasite cultures has long been pivotal in advancing parasitology, with broad applications in medicine, veterinary science, and biology. Laboratory cultures are invaluable tools for studying parasite biology, host-parasite interactions, and the development of treatments and vaccines. However, cultures of digenean trematodes under laboratory conditions remain a challenging yet critical endeavour in parasitology. These parasites hold significant importance to both human health and ecological systems. Nevertheless, trematodes exhibit a complex life cycle involving multiple hosts, which demands innovative culture methods. This review aims to provide a comprehensive overview of laboratory culture techniques for digenean trematodes, covering in vitro, in vivo, and in ovo approaches. These techniques are discussed in order across the different parasitic life stages of trematodes, from sporocyst/redia to adults, as well as the handling of trematode eggs, with a focus on optimising media composition, host-cell integration, and environmental parameters. In vitro approaches, particularly those using host-cell-based media or host-derived sera, have shown promise for certain zoonotic species. However, cultures of marine trematodes often face limitations due to suboptimal media protocols. On the other hand, in vivo and in ovo methods, while generally achieving higher success rates, raise ethical and logistical concerns. Despite notable progress, the standardisation of protocols and the adaptation of techniques for a broader range of species remain significant challenges in digenean trematode cultures. Future research should prioritise the development of host-cell-based media, innovative culture technologies, and integrative molecular and proteomic tools to address these limitations and further our understanding of trematode biology.