A parasitic worm that grows up to a metre long has been found in the foot of a Melbourne man who is believed to have been living with it for years.
The parasite, which usually travels through the walls of its victims' intestines and digs through their body to try to exit through a painful blister on their skin, was recently diagnosed in a Sudanese migrant who had been living in Australia for four years.
Dr Jonathan Darby, an infectious diseases physician at St Vincent's Hospital, said the 38-year-old man sought help for a swollen foot that had been painful for about a year, prompting doctors to wonder if he had stood on something that had become stuck in his foot or had caused an infection.
But to their surprise, an X-ray showed what appeared to be two pieces of curled up "Guinea worm" or Dracunculiasis medinensis in his ankle and foot.
Despite its ability to grow to great lengths, the two pieces of worm were only several centimetres long, probably because it had died and started to degenerate inside the man. It was surgically removed and the man made a full recovery.
The parasite, found in Africa, enters people through drinking water containing water fleas that have ingested Dracunculus larvae. Once swallowed, the larvae burrow through the walls of the intestines where they develop into adult worms that look like spaghetti. The female worms usually then move through tissue in the abdomen and into the legs, feet or toes, where they try to emerge through skin, producing painful blisters or ulcers.
Dr Darby said this usually causes people a burning sensation that makes them put the affected part of their body into water. If the worms meet water, the females discharge their larvae, setting in motion a new life cycle.
"That whole process can take years. It can sit inside the human body alive for years or die, degenerate, and then cause problems in the area like it did for our patient," he said.
In developing countries, Dr Darby said live worms are usually delicately pulled from people's exit wounds over days or weeks to ensure they don't break and cause more harm.
"If you google it, you'll find some fairly dramatic photos of people getting match sticks and twirling their worm out centimetre per day," he said.
Dr Darby said the Melbourne man - a Sudanese migrant who had not left Australia since he arrived four years ago - was most likely infected in Africa where the parasite is still found in Southern Sudan, Ethiopia, Ghana and Chad despite efforts to eradicate it. While there is no treatment for the disease, people carrying the parasites cannot infect others.
Details of the case were published in the medical journal Pathology to inform doctors about the possibility of it in people with symptoms, particularly migrants.
"Increased refugee and migration movement from endemic as well as recently certified free countries may lead to cases of imported dracunculiasis being reported, and hence clinical vigilance in non-endemic countries remains important," the doctors wrote.
