A client presents with elephantiasis of the lower legs. Which helminthic infection is most likely suspected?

In cases of elephantiasis, the most likely suspected helminthic infection is filariasis. This condition is typically caused by a type of parasitic worm from the filarial family, particularly Wuchereria bancrofti. These worms are transmitted to humans through mosquito bites, leading to lymphedema and, over time, significant swelling and thickening of the skin, which is characteristic of elephantiasis.

The pathology associated with filariasis involves the obstruction of lymphatic vessels, causing fluid accumulation and subsequent swelling. This is distinct from the other listed conditions which do not typically manifest as elephantiasis. Ascariasis involves infection by the roundworm Ascaris lumbricoides, leading to gastrointestinal issues rather than lymphatic obstruction. Schistosomiasis is caused by trematode worms and primarily affects the urinary and gastrointestinal systems, presenting with symptoms such as hematuria or gastrointestinal bleeding but not with elephantiasis. Trichinosis results from infection with Trichinella spiralis and is characterized by gastrointestinal symptoms and muscle pain, not by elephantiasis.

Thus, the connection between filariasis and the clinical presentation of elephantiasis makes filariasis the most likely suspected helminthic infection in this scenario.