200 Years. 200 Stories. Story 81: “I Would Not Eat Worm Eggs and Ham … Wait, What??? ”

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photo of parasite specimens
Human parasites collected by Joseph Leidy. The one on the far left is Ascaris lumbricoides, or giant roundworm. It causes ascariasis, a parasitic disease that is very common in many tropical and subtropical countries. The other three specimens are Taenia saginata, or beef tapeworm. It's the culprit of taeniasis, a disease that is transmitted between beef cattle and humans. This parasite can be especially long-lived and may reach total lengths in excess of 30 feet. The specimens in the two middle jars actually belong to a single tapeworm.

I Would Not Eat Worm Eggs and Ham … Wait, What???

Joseph Leidy, one of the Academy’s foremost scientists of the 19th century, accidentally discovered the link between food and tapeworm infection in humans one morning during breakfast. As he was about to start eating his breakfast ham, he noticed numerous small, white flecks decorating the meat. Most people would have pushed away their plates in disgust and thrown their meals in the garbage. Being an Academy scientist with a full arsenal of research tools at his disposal, Leidy simply took a meat sample back to his laboratory and placed it under the microscope. He discovered that the little white specks were in fact tapeworm larvae cysts. These cysts were a variant called Trichina spiralis, which he already was familiar with because of his work with tapeworm infection in humans. This discovery would save countless lives.

The Academy’s Malacology Department has several tapeworm samples that Joseph Leidy collected, making them more than 100 years old. These samples enabled Leidy and his peers to gain knowledge of food-borne illness, making tapeworm infection a rarity today. You can thank Leidy for the comfort you find in knowing that the only eggs you’ll be eating with your ham will most likely be scrambled, fried, or in the case of Sam-I-Am, green.

Find out more about Joseph Leidy!

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