Sentence:  Dr. Elliott said that in Argentina, researchers found that patients with multiple sclerosis who were infected with the human <WSD>whipworm</WSD> had milder cases and fewer flare-ups of their disease over a period of four and a half years. 
Meaning of the word marked with <WSD> tags:  (ver=170605), a roundworm, causing trichuriasis when it infects a human large intestine.