Man infected by one of 'world's largest human parasites' after eating raw fish from a lake in India

Daily Mail​

21-04-2025

A 35-year-old Indian man who couldn't urinate learned his problem was being caused by a parasitic worm growing inside him.
Disturbing images published by medics who treated the man show the red worm after it emerged out of his bladder, alive and wriggling.
Analysis revealed the worm belonged to a species called Dioctophyma renale, commonly known as the 'giant kidney worm'.
Interviews with the patient revealed that he commonly ate raw fish from a lake near his home, and medics suspect this was likely how he became infected.
Eating raw or undercooked fish is a known way for humans to become infected as these animals can carry the worm larvae inside their bodies.
Medics, who treated the unnamed man in the city of Meerut, India, said he came into hospital in June 2015 complaining of being unable to urinate and suffering a fever.
Staff who examined his vital signs found he was pale and had an elevated heart rate.
Doctors - suspecting he had an infection - admitted him to hospital and gave him antibiotics.
They also inserted a catheter - a soft flexible tube that empties urine into a plastic bag - to help empty his bladder.
However, on his second day in hospital the patient alerted staff to the presence of a wriggling worm - and some blood - in the catheter bag.
A report, published in the Journal of Clinical and Diagnostic Research, details that the 'blood red' worm was 11.8in long with a diameter of 0.13in and had anatomical features identifying it as a male giant kidney worm.
The man was lucky that he hadn't been infected with a female specimen as these can grow over 3ft.
Medics continued to analyze the man's urine for the next three days but found no additional worms or any traces of any eggs.
The man also revealed to medics he had urinated a few of the worms in the past.
Concluding their report the authors said the man, after a short period of treatment, left hospital against medical advice so they were unable to follow-up his care.
Human infection of giant kidney worm, medically called dioctophymiasis, is very rare.
A 2019 review by Chinese researchers only found 37 human cases recorded in medical literature, some being infected with as many as 15 worms.
While half of patients had a history of eating raw or undercooked fish or frogs, the potential transmission route was unknown for the remaining half.
Drinking un-boiled water where these animals reside is also a potential transmission route.
Once in the human body the worm larvae migrate to the kidney where they then grow into adult worms and can live for up to five years.
They can cause issues like blocking the flow of urine to the bladder, kidney swelling, and tissue death.
Treatment varies depending on the extent of the infection and how much of the kidney has been damaged.
Minor cases can be treated with medication, but more serious infections can require surgery, including potentially removal of the entire kidney.
Medics have noted that due to its rarity dioctophymiasis is often misdiagnosed among patients.
Human infection with giant kidney worm is rare with the parasite more commonly found in carnivorous mammals like dogs, otters, and weasels.