Dr. Grassi Eats Worms

Giovanni Battista Grassi
Worm Incubator

On 10 October 1878, the Sicilian doctor Giovanni Battista Grassi was conducting an autopsy when he found the large intestine of the corpse to be riddled with tapeworm (Ascaris lumbricoides) and their eggs. Grassi immediately realized he could ingest some of the eggs and prove it was possible to infect oneself with tapeworms in this way.

However, in order to conduct his experiment properly, Grassi first needed to determine that he wasn’t already infected. So he fished the eggs out of the intestines and placed them in a solution of moist excrement, where he could keep them alive indefinitely. Then he microscopically examined his own faeces every day for almost a year to confirm his lack of infection.



Ascaris lumbricoides and eggs
Finally, on 20 July 1879, he felt confident he was free of worms, so he spooned 100 of the eggs out of their faecal home and swallowed them down. A month later, much to his pleasure, Grassi experienced intestinal discomfort and then found tapeworm eggs in his stool. His experiment was a success. Having confirmed his infestation, he treated himself with an herbal anti-worm medicine, and flushed the immature parasites out of his body.

After the example set by Grassi, self-infection with worm eggs became something of a gruesome rite of passage among parasitologists. In 1887, Friedrich Zschokke and his students at the University of Basel ingested tapeworm eggs and grew worms up to six feet in length in their intestines. In 1922, the Japanese paediatrician Shimesu Koino set a record by consuming 2000 mature Ascaris lumbricoides eggs, giving himself such a full-blown infection that he began coughing up larval worms from his lungs. And as late as 1984, the Soviet researcher V.S. Kirichek reported sampling worm eggs he found in the brains of arctic reindeer.