If you're squeamish, here's a story you might not want to hear.
Doctors in England were having a hard time figuring out what was giving a Chinese man headaches and seizures and causing disturbances in his sense of smell. After the 50-year-old man tested negative for various diseases, a series of brain scans revealed the cause of the strange symptoms -- a tapeworm had been living inside the man's brain for four years. Freaky!
The parasite measured about one centimeter in length and had tunneled five centimeters through the man's brain before surgeons removed it in 2012, The Guardian reported. The man is now reportedly cured of the infection.(Story continues below.)
Researchers identified the parasite as a Spirometra erinaceieuropaei, a rare species of tapeworm normally found in China, South Korea, Japan and Thailand. Only 300 cases of infection by the parasite have been reported in humans.
Scientists believe that Spirometra erinaceieuropaei may be contracted by eating crustaceans and reptiles that harbor it, or by using a Chinese remedy for sore eyes that is made from frogs.
"We did not expect to see an infection of this kind in the U.K., but global travel means that unfamiliar parasites do sometimes appear," Dr. Effrossyni Gkrania-Klotsas, a researcher at the department of infectious disease at Addenbrooke's NHS Trust in Cambridge, said in a written statement.
Dr. Effrossyni Gkrania-Klotsas and her colleagues used a sample of the worm to sequence the creature's entire genome for the first time. The results of this research were published online on Nov. 21 in the journal Genome Biology.
The researchers say the newly sequenced genome, which is 10 times bigger than the genome of any other tapeworm, will shed light on how the parasite worms its way into humans and other host animals--and help point the way to new drug treatments, according to the researchers.
"By comparing the genome to other tapeworms we can see that certain gene families are expanded," lead researcher Dr. Hayley Bennett, a researcher at the Wellcome Trust Sanger Institute in Hixton, England, said in a written statement. "These possibly underpin this worm's success in a large variety of host species."
Most parasitic tapeworms that infect humans and animals--including Spirometra erinaceieuropaei--live in the intestines, cause few symptoms, and are easy to treat. However, in rare cases, including this one, the worms can make their way to the brain.
This is a magnified view of the worm and adjacent brain tissue from biopsy.