There is an 8 cm long parasite in the brain, which is still wriggling when taken out ...
Recently, Australia reported the world's first case of Ophidascaris robertsi infecting humans, and doctors removed a parasite up to 8 cm long from the patient's right frontal lobe.
Screenshot of the paper
The case was published in the September issue of EID (Emerging Infectious Diseases), a journal of the US Centers for Disease Control and Prevention (CDC).
Abdominal pain and diarrhea were admitted to the hospital, and the condition recurred within a year
In January 2021, a 64-year-old woman from New South Wales, Australia, presented to a local hospital complaining of abdominal pain, diarrhoea, dry cough, and night sweats lasting three weeks. The patient's history also includes diabetes, hypothyroidism, and depression. The patient was previously diagnosed with community-acquired pneumonia and has not fully recovered.
Blood tests showed eosinophils as high as 9.8×10^9/L (normal <0.5×10^9/L) and C-reactive protein up to 102 mg/L (normal <5 mg/L). CT shows multifocal opacy of the lungs with ground-glass changes and liver and spleen damage. Up to 30% of eosinophils are present in bronchoalveolar lavage fluid, but there are no signs of malignancy or pathogenic organisms, including parasites.
After ruling out other causes, doctors diagnose eosinophilic pneumonia of unknown etiology and take prednisolone to suppress immunity and improve symptoms.
Three weeks later, the patient was readmitted to the hospital due to recurrent fever and persistent cough during the medication. Blood tests and CT results are similar to those three weeks ago, and lung biopsy is consistent with eosinophilic pneumonia. Cultures of bacteria, fungi, and mycobacteria are negative. Echinococcus, fascioliformis, schistosomiasis antibodies did not show a positive reaction. No parasite eggs were found in stool specimens.
Also, the detection of monoclonal T cell pleocytosis suggests possible T-cell-driven eosinophilia syndrome (HES). Doctors raise the dose of prednisolone in patients and add mycophenolate mofetil in tandem to enhance immunosuppressive effects.
Subsequently, with the improvement of the patient's condition, the number of eosinophils was controlled within the normal range with the addition of mepolimab (interleukin-5 monoclonal mab).
Snake roundworms were found in the brain, the world's first case of infection
After about one year of treatment, the patient developed symptoms of forgetfulness and worsened pre-existing depression, with brain MRI showing 13×10 mm of enhanced lesions in the right frontal lobe.
In June 2022, the patient underwent an open biopsy of the brain, and doctors found a linear structure in the lesion area, and observed the resection of the lesion and found that it was a live, peristaltic parasite (80mm long, 1mm diameter). Circumferential durotomy and corticotomy were subsequently performed, and no other worms were found.
Ophidascaris robertsi larvae removed
Source: Reference 1
Based on the known epidemiological distribution and appearance characteristics, the worm has been tentatively identified as the third stage larvae of Ophidascaris robertsi. Subsequently, the strain was confirmed after sequencing by the University of Sydney and the University of Melbourne.
After surgery, lung and liver lesions regressed, but spleen lesions did not change. After stopping immunosuppressive therapy, antiparasitic drugs are taken to eliminate potential larvae from other organs. After treatment, the patient's eosinophils remained normal and psychiatric symptoms improved.
Ophidascaris robertsi is found in Australia, and its ultimate host is the local carpet python (Morelia spilota). Adult roundworms parasitize the esophagus and stomach of pythons, worm eggs are excreted through feces, various small mammals are intermediate hosts, larvae develop in vivo after feeding on worm eggs, and the life cycle of the parasite is completed after the python eats the infected intermediate host [2].
Human infection with Ophidascaris Robertsi has not been previously reported.
The patient lives near the lake where carpet pythons inhabit, and although there is no direct contact with the pythons, she often collects local plants (Tetragonia tetragonioides, New Zealand spinach) from around the lake for cooking. Plants contaminated with eggs may have been eaten directly or indirectly entered the digestive tract through hands or utensils contaminated with eggs.
The patient's clinical progression suggests a dynamic migration of larvae to multiple organs, eosinophilia in blood and tissues suggests visceral migration, and immunosuppressive therapy may prompt migration to the central nervous system.
Acknowledgements: This article has been reviewed by the Institute of Parasitic Diseases Prevention and Control of the Chinese Center for Disease Control and Prevention @小虫子大能量
Curated by: Yuu. | Executive producers: Gyouza, Carollero
Information collation: artichoke flowers
Image source: Reference 1
Resources:
[1] Hossain M, Kennedy KJ, Wilson HL, et al. Human Neural Larva Migrans Caused by Ophidascaris robertsi Ascarid. Emerging Infectious Diseases. 2023;29(9):1900-1903. doi:10.3201/eid2909.230351.
[2] Gonzalez-Astudillo V, Knott L, Valenza L, Henning J, Allavena R. Parasitism by Ophidascaris robertsi with associated pathology findings in a wild koala (Phascolarctos cinereus). Vet Rec Case Rep. 2019;7:e000821. DOIExternal LinkGoogle ScholarExternal Link
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