A neurosurgeon investigating a woman’s mystery symptoms in an Australian hospital has plucked a three-inch live worm from the patient’s brain.
In a remarkable medical case, the diligent efforts of neurosurgeon Hari Priya Bandi eventually solved this unsettling mystery.
The patient had been experiencing baffling symptoms that defied conventional diagnosis.
Dr Bandi, a clinical lecturer and examiner for the ANU Medical School and examiner for the Royal Australasian College of Surgeons clinical exam, performed a biopsy.
Extracting a wriggling, three-inch worm from the brain, the seasoned neurosurgeon later admitted to feeling a sense of discomfort upon this shocking revelation.
The larva of an Australian native roundworm was a species previously unrecognised as a human parasite and designated as Ophidascaris robertsi.
These parasites are typically associated with carpet pythons, their natural hosts. As a result of the astonishing finding, Dr Bandi and her colleagues authored a compelling article recounting the extraordinary case.
The 64-year-old woman from south-eastern New South Wales, Australia, was admitted to a local hospital in late January 2021 after three weeks of abdominal pain and diarrhoea, followed by a dry cough and night sweats.
Her medical history included diabetes mellitus, hypothyroidism, and depression. She was treated for community-acquired pneumonia with doxycycline and had not recovered fully.
The team recall that during three months in 2022, the patient experienced forgetfulness and worsening depression.
They write: ‘In June 2022, she underwent an open biopsy. We noted a string-like structure within the lesion, which we removed; it was a live and motile helminth (80 mm long, 1mm diameter).
‘In this case, the patient resided near a lake area inhabited by carpet pythons. Despite no direct snake contact, she often collected native vegetation, warrigal greens, from around the lake to use in cooking. We hypothesised that she inadvertently consumed O. robertsi eggs either directly from the vegetation or indirectly by contamination of her hands or kitchen equipment.
‘The patient’s clinical and radiologic progression suggests a dynamic process of larval migration to multiple organs, accompanied by eosinophilia in blood and tissues, indicative of visceral larva migrans syndrome. We suspect the splenic lesions are a separate pathology because they remained stable and were not PET avid, unlike the pulmonary and hepatic lesions.’
They suggest this case highlights the difficulty in obtaining a suitable specimen for parasitic diagnosis and the challenging management decisions regarding immunosuppression in the presence of potentially life-threatening HES.
Although visceral involvement is common in animal hosts, the invasion of the brain by Ophidascaris larvae had not been reported previously.
‘The patient’s immunosuppression may have enabled the larvae to migrate into the central nervous system (CNS). The growth of the third-stage larva in the human host is notable, given that previous experimental studies have not demonstrated larval development in domesticated animals, such as sheep, dogs, and cats, and have shown more restricted larval growth in birds and non-native mammals than in native mammals,’ they say.
‘After we removed the larva from her brain, the patient received anthelmintics and dexamethasone to address potential larvae in other organs. Ophidascaris larvae survive for long periods in animal hosts; for example, laboratory rats have remained infected with third-stage larvae for more than four years. The rationale for ivermectin and albendazole was based on data from the treatment of nematode infections in snakes and humans. Albendazole has better penetration into the CNS than ivermectin. Dexamethasone has been used in other human nematode and tapeworm infections to avoid deleterious inflammatory CNS responses following treatment.’
They conclude: ‘This case emphasises the ongoing risk for zoonotic diseases as humans and animals interact closely. Although O. robertsi nematodes are endemic to Australia, other Ophidascaris species infect snakes elsewhere, indicating that additional human cases may emerge globally.’
Their comprehensive account is published in the latest edition of Emerging Infectious Disease.
Figure 2. Ophidascaris robertsi nematode infection was detected in a 64-year-old woman from southeastern New South Wales, Australia. A) MRI of the patient’s brain by fluid-attenuated inversion recovery demonstrating an enhancing right frontal lobe lesion, 13 × 10mm. A live third-stage larval form of Ophidascaris robertsi (80mm long, 1mm diameter) was removed from the patient’s right frontal lobe. C) Live third-stage larval form of O. robertsi (80mm long, 1mm diameter) under a stereomicroscope (original magnification ×10).
