Sentence:  Other helminths or wormlike fellow travellers became common in the human gut, including the "Enterobius" (pinworm or threadworm), the yards-long tapeworm, and the <WSD>filarial</WSD> worms which cause elephantiasis and African river blindness. 
Meaning of the word marked with <WSD> tags:  Of or pertaining to the microscopic parasitic worms known as filaria, or an infestation thereof.