Doctors in Australia had examined, scanned and tested a woman to find out why she was ill after she was hospitalized with abdominal pain and diarrhoea. They were not prepared for what they found.
A red worm, eight centimeters in size, lived in the woman's brain.
The worm was removed last year after doctors spent more than a year trying to find the cause of the woman's discomfort.
The search for the answer and the startling discovery were described this month in Emerging Infectious Diseases, a monthly journal published by the Centers for Disease Control and Prevention.
The woman, identified in the article as a 64-year-old resident of south-eastern New South Wales, Australia, was admitted to hospital in January 2021 after suffering from three weeks of diarrhea and abdominal pain. She had a dry cough and night sweats.
Scientists and doctors from Canberra, Sydney and Melbourne said in the journal article that the woman was initially told she had a rare lung infection, but the cause was unknown.
Her symptoms improved with treatment, but weeks later she was hospitalized again, this time with a fever and cough. Doctors then treated her for a group of blood disorders known as hypereosinophilic syndrome, and the drugs they used suppressed her immune system.
For a period of three months in 2022, she suffered from forgetfulness and a worsening depression. An MRI revealed she had brain damage, and in June 2022, doctors performed a biopsy.
Inside the lesion, doctors found a “thread-like structure” and removed it. The structure was a red, live parasitic worm about 3.15 inches long and 0.04 inches in diameter.
They determined it was an Ophidascaris robertsi, a species of roundworm native to Australia that reproduces in a large snake, the carpet python got its name from its intricate markings. The pythons pass the worm's eggs in their feces. The eggs are then ingested by small mammals and the worms can grow inside.
Roundworms infect hundreds of millions of people worldwide. according to the Cleveland Clinicbut the researchers in Australia said this is the first report of a human being infected by the worm species Ophidascaris.
The woman may have contracted the worm the same way small animals usually do: by accidentally eating worm eggs.
Carpet pythons were located in a lake area near where the woman lived, the article said. She had no direct contact with the snakes, but often gathered spinach-like warrigal vegetables around the lake to cook. The article said she may have accidentally consumed worm eggs because she ate the vegetables or because her hands or kitchen were contaminated with them.
Scott Gardner, professor of biological sciences and curator of the Manter Parasitology Laboratory at the University of Nebraska-Lincoln, said people don't need to panic if they could contract ophidascaris from snakes and that they should practice good hygiene to avoid becoming infected with the parasite.
“Many of the parasites that can affect humans do so because we are in the wrong place at the wrong time,” said Dr. Gardner, who was not involved in the Australian study, in an interview. “So we're picking up some eggs that shouldn't be entering us, and if we're immunocompromised, we can get a pretty serious infection.”
Karina Kennedy, director of microbiology at Canberra Hospital and author of the article, said in a press release that the woman's first symptoms “were likely due to the migration of roundworm larvae from the intestines and into other organs such as the liver and lungs.”
However, in the early stages of the woman's illness, doctors could not find any evidence of the parasite, said Dr. Kennedy.
“At the time, trying to identify the microscopic larvae, which had never before been identified as causing human infection, was a bit like trying to find a needle in a haystack,” she said.
Six months after the brain surgery, the woman's psychiatric symptoms persisted but had improved, the article said. She was also treated with medication to kill any worm larvae that may have been lodged in her other organs. She is still monitored by infectious disease and brain disease specialists.
dr Kennedy, who is also an associate professor at the Australian National University School of Medicine, advised people to wash their hands after gardening and touching harvested produce, and to thoroughly wash food and surfaces used for cooking.
In the article, the scientists and doctors involved in the woman's case said their experience highlighted the risk of disease transmission from animals to humans. Outbreaks of these diseases have become more frequent in recent decades, accounting for about 60 percent of all known infectious diseases and 75 percent of all emerging diseases. according to CDC.
Although the type of worm that infected the woman is endemic to Australia, the species Ophidascaris infects snakes in other parts of the world. Scientists said in the article that this case “shows that more human cases could be emerging around the world.”
