A Chinese descent, based in UK had recently visited China, which
along with South Korea, Japan and Thailand, has more regular occurrences
of the parasite known as Spirometra erinaceieuropaei. Four years
earlier the man had first experienced symptoms, such as headaches, which
the team of doctors at Addenbrookes Hospital, in Cambridge, had
treated as tuberculosis. But when he returned, this is what one of the doctors had to say, "When
he reappeared, he had new symptoms," says Gkrania-Klotsas. The worm was
now pushing on a new part of his brain, causing seizures and weakness
in his legs. The condition associated with his infection was in fact
Sparganosis. There is no known drug to effectively treat the infection
meaning that upon diagnosis doctors had to be quick to remove the worm
surgically.
"These
worms are pretty mysterious," says geneticist Hayley Bennett from the
Wellcome Trust Sanger Institute, in Cambridge, "We know it has a very complicated life cycle."
The
adult form of the Spirometra tapeworm only occurs in the intestines of
cats and dogs but as these animals shed the worms' eggs in their feces
the eggs can enter, and contaminate, water. The resulting juvenile form
of tapeworm -- known as larvae -- can then stay in the water within
certain small crustaceans or end up in frogs and snakes. As larvae they
can invade humans through ingestion or direct contact with infected
animals. The patient in Cambridge was thought to have accidentally drunk
water whilst swimming in an infected lake, according to
Gkrania-Klotsas. The worm then took hold.
Once
you consume them, they can move throughout your body -- your eyes, your
tissues and most commonly your brain. They leave doctors puzzled in
their wake as they migrate and settle to feed on the body they're
invading; a classic parasite, but this one can get into your head.
"The
larvae can encyst in the brain or somewhere else," says Bennett. The
consequences of these cysts can be tissue damage, blindness, paralysis
or even death.
