8-cm live worm removed from woman's brain in world's 1st discovery

SYDNEY: In a world's first such case, a team of Australian neurosurgeons has removed an eight cm-long parasitic roundworm from a patient who complained of forgetfulness and depression.

The world's first case of a new parasitic infection in humans was discovered by researchers at The Australian National University (ANU) and the Canberra Hospital after they detected a live roundworm from a carpet python in the brain of a 64-year-old Australian woman.

The Ophidascaris robertsi roundworm was pulled from the patient after brain surgery -- still alive and wriggling. It is suspected larvae, or juveniles, were also present in other organs in the woman’s body, including the lungs and liver.

"This is the first-ever human case of Ophidascaris to be described in the world," said Sanjaya Senanayake, leading ANU and Canberra Hospital infectious disease expert in a paper published in the journal Emerging infectious diseases.

"To our knowledge, this is also the first case to involve the brain of any mammalian species, human or otherwise. Normally the larvae from the roundworm are found in small mammals and marsupials, which are eaten by the python, allowing the life cycle to complete itself in the snake," Senanayake added.

Ophidascaris robertsi roundworms are common to carpet pythons. It typically lives in a python's oesophagus and stomach, and sheds its eggs in the host's faeces. Humans infected with Ophidascaris robertsi larvae would be considered accidental hosts.

The researchers say the woman, from southeastern New South Wales in Australia, likely caught the roundworm after collecting a type of native grass, Warrigal greens, beside a lake near where she lived in which the python had shed the parasite via its faeces. The patient used the Warrigal greens for cooking and was probably infected with the parasite directly from touching the native grass or after eating the greens. She initially developed abdominal pain and diarrhoea, followed by fever, cough and shortness of breath.

"In retrospect, these symptoms were likely due to migration of roundworm larvae from the bowel and into other organs, such as the liver and the lungs. Respiratory samples and a lung biopsy were performed; however, no parasites were identified in these specimens," said Karina Kennedy, Canberra Hospital’s Director of Clinical Microbiology and Associate Professor at the ANU Medical School, Senanayake said the world-first case highlighted the danger of diseases and infections passing from animals to humans, especially as we start to live more closely together and our habitats overlap more and more.

"There have been about 30 new infections in the world in the last 30 years. Of the emerging infections globally, about 75 per cent are zoonotic, meaning there has been transmission from the animal world to the human world. This includes coronaviruses," he said. The patient continues to be monitored by the team of infectious diseases and brain specialists.