CDC Investigation Finds Man got Cancer from Tapeworms
Experts from the Centers for Disease Control and Prevention (CDC) have made a startling find.
The scientists conducted an investigation into the death of a 41-year-old HIV positive man from Colombia and discovered that he had developed tumors from tapeworms. The patient sought out care in 2013 at a hospital in Medellin. At the time, he was dealing with a fever, difficulties breathing and a tapeworm infestation. He had also lost a significant amount of weight.
When the doctors tried to understand why he was having trouble breathing, they found something in his lungs that looked like tumors. However, unlike regular tumors, the ones in his lungs were made up of "cells that were not human," Dr. Atis Muehlenbachs, the lead author of the report and a pathologist at the CDC, explained reported by NPR.
"This has been the most unusual case, it caused many sleepless nights," he said to BBC News.
After conducting DNA tests, Dr. Muehlenbachs and experts from the Natural History Museum in London were able to confirm that the tumors were made up of tapeworm cells. These tapeworm tumors were also found in the man's liver and adrenal glands.
"We knew invertebrates can grow tumors, but the fact that one can invade and disseminate in a human and make them sick just really, really defied belief," Dr. Muehlenbachs said.
Biologist Peter Olson from London reasoned that the tapeworm could have transmitted cancer when it was reproducing inside the man. Olson explained that the dwarf tapeworm (Hymenolepis nana), which usually does not cause severe problems in humans, could have mutated in the man's compromised gut. Every time the tapeworm multiplied, the risks of mutation increased, which could then lead to cancerous cells.
"There is something very special about this species. It is able to carry out its whole lifecycle in one host and that is absolutely unique," Olson said to BBC. "They were dividing and proliferating out of control and that is really what defines a cancer so they had a tape worm tumor."
He added, "We don't know how rare this disease is. It's the most common tapeworm worldwide, and HIV is also very common. So we're very eager to learn about other cases and potentially those that we might have an opportunity to attempt treatment."
The case was published in the New England Journal of Medicine.