Fig. 1

The Trichobilharzia spp. lifecycle. The lifecycle usually involves pulmonate freshwater snails as intermediate hosts and waterfowl as final hosts. Human infections occur when cercariae incidentally penetrate human skin during water-bound activities, potentially causing swimmer’s itch. *The eggs of nasal Trichobilharzia, such as Trichobilharzia regenti, already hatch into miracidia in the nasal tissue of the final host, leaving the nasal cavity while the host drinks or feeds (dotted line). This is in contrast to the lifecycle of visceral Trichobilharzia, whereby miracidia emerge from eggs following contact with water. Created with BioRender.com