Worm Lives in Man's Head for Four Years

A worm lived in a man’s head near his brain for four years, according to a new study that also determined the parasite had an incredibly long genome.

The research, conducted at the Wellcome Trust Sanger Institute, reveals the genetic secrets of the elusive parasite with origins in the Far East. It’s a tapeworm known as Spirometra erinaceieuropaei that no human would want as a guest.

The worm causes sparganosis, meaning inflammation of the body’s tissues in response to the parasite. When this occurs in the brain, it can result in seizures, memory loss and headaches. Thankfully the UK man lived to tell the tale and is now doing well.

“We did not expect to see an infection of this kind in the UK, but global travel means that unfamiliar parasites do sometimes appear,” co-author Effrossyni Gkrania-Klotsas from the Department of Infectious Disease at Addenbrooke’s NHS Trust said in a press release.

It is thought that people may become infected with the worm by accidentally consuming tiny infected crustaceans from lakes, eating raw meat from reptiles and amphibians, or by using a raw frog poultice, which is a Chinese remedy to calm sore eyes.

Before the nearly ½-inch-long parasite was diagnosed in the man and successfully removed by surgery, it had traveled 2 inches from the right side of the man’s brain to the left. It’s little wonder that the victim reported suffering from headaches. The tapeworm was reserved for the later genome sequencing.

Fortunately for the patient, the gene’s DNA sequence revealed that the parasite was the more benign of two known sparganosis-causing worm species. The researchers, however, were shocked by the size of the tapeworm’s genome.

Spirometra erinaceieuropaei’s genome turned out to be 1.26Gb long, making it 10 times larger than other tapeworm genomes and one-third the size of the human genome. The medical experts suspect that some of this comes from an increase in the number of genes that may help the parasite to break up proteins and invade its host, coupled with the fact that the genome is much more repetitive than other tapeworm genomes.

The tapeworm was also found to possess a large selection of molecular motors for moving proteins around its cells, which could underpin the large changes in body shape and environmental adaptions that the worm undergoes during its complicated lifecycle.

Read more at Discovery News