Cambridge scientists have unraveled the genetic code of a rare tapeworm that lived inside a patient's brain for at least four years. Researchers hope it will present new opportunities to diagnose and treat this invasive parasite. Matthew Stock reports.
This sequence of MRI scans shows the movement of a tapeworm inside a person's brain over four years. Scientists in Cambridge say the parasite, measuring up to 2 centimetres, had never been reported in the UK before. The patient - a 50-year-old Chinese man - is believed to have been infected on a trip to his home country. He was admitted to hospital suffering headaches and seizures, but neuropathologist Andrew Dean said intitial tests left doctors baffled. (SOUNDBITE) (English) DR. ANDREW DEAN, CONSULTANT NEUROPATHOLOGIST, SAYING: "Rather unexpectedly, the centre of gravity of the lesion was moving slowly from one side of the brain into the other side of the cerebral hemisphere; leaving a kind of trail of scar tissue behind it." After successful removal from the brain, they found the tapeworm had travelled about 5 centimetres. Dr Hayley Bennett from the Wellcome Trust Sanger Institute was part of the team enlisted to identify the species. They sequenced one particular gene - known as the 'barcode of life'. (SOUNDBITE) (English) DR. HAYLEY BENNETT FROM THE WELLCOME TRUST SANGER INSTITUTE, SAYING: "We take that DNA and we chop it up into manageable pieces, and we actually use these fragments and read the sequence of the DNA, so that's As, Ts, Cs and Gs, a hundred letters at a time... And it's sort of like a linear jigsaw puzzle, where you're trying to piece together all this information." Dr. Matthew Berrimen says their genomic research will benefit scientists the world-over. (SOUNDBITE) (English) DR. MATTHEW BERRIMAN, GROUP LEADER AT WELLCOME TRUST SANGER INSTITUTE, SAYING: "By producing a genome sequence we're laying open the instruction manual to an organism. Scientists from all over the world can now dip into those data and instead of having to do early experiments, they can explore their hypothesese just using the data itself." Infectious disease consultant Dr Effrossyni Gkrania-Klotsas hopes this will lead to more effective medication. (SOUNDBITE) (English) DR. EFFROSSYNI GKRANIA-KLOTSAS, INFECTIOUS DISEASE CONSULTANT AT CAMBRIDGE UNIVERSITY HOSPITAL, SAYING: "Our drugs are very crude in a way, they're very blunt instruments. So understanding more what the parasite is likely respond to helps us design medication that is better for this particular type of infection. It also gives us insights on how to go about designing medication for all kinds of parasites." Doctors report the patient is now 'systemically well' with no notable side-effects after hosting the tapeworm for so long.