A tapeworm that normally infects barn animals and dogs came as a literal shock for one 35-year-old French woman, according to a case report published Thursday in The New England Journal of Medicine. The woman learned her three-month ordeal of worsening muscle weakness and electrical zaps in both legs was ultimately caused by worms that had lodged themselves inside her spine.
By the time the unnamed woman visited an emergency department, she had been struggling to stay upright, regularly falling without reason. Following a physical examination, it was confirmed that the woman’s legs had started to lose sensation and she could barely flex her feet. Blood tests also suggested she had come down with some sort of infection. But it wasn’t until her MRI came back that the culprit was spotted: a lumpy lesion in the middle section of her backbone.
The woman had the lesion — and the 9th thoracic vertebra where it was found — surgically removed, with the hole left behind in the spine repaired via an implant. And upon further examination, the lesion was found to contain larval cysts of the dog tapeworm, formally known as Echinococcus granulosus.
As the name implies, the worm typically sticks to four-legged animals, though humans can occasionally get caught in its path. The adult worm breeds eggs that are pooped out of its primary host (i.e. dogs), where they get ingested by any number of secondary hosts such as sheep, goats, and other grazing types. The eggs find their way to the small intestine, where they develop into cysts. These cysts then ride the bloodstream and attach themselves to other organs where they continue to grow, all so they can await the very special day when another dog comes around and eats the cyst-filled organs of their host animal, and the process begins anew.
In people, though, this process usually hits a dead end for reasons that should be obvious. But the cysts left behind can still do some serious damage. They typically infest the lungs or liver, but it’s not unheard of them to end up in the central nervous system or bones. You can also tote around these tiny worm friends for years before becoming sick. It’s not 100 per cent clear how the woman got infected, but she had come into contact with cattle at some point before her symptoms started.
Luckily, the woman’s story ends about as happily as it can. Nine months after the procedure, and following a course of antiparasitic medication, the woman showed no symptoms or no signs of a continued infestation. [The New England Journal of Medicine]