04 December 2023: Articles
Molecular Diagnosis of Severe -Induced Eosinophilic Meningitis: A Case Report Emphasizing the Need for Accurate Detection Methods
Challenging differential diagnosis, Diagnostic / therapeutic accidents, Rare disease
Wei-Ting Luo


DOI: 10.12659/AJCR.941925
Am J Case Rep 2023; 24:e941925
Abstract
BACKGROUND: Angiostrongylus cantonensis, also known as the rat lungworm, is the most common parasitic cause of human eosinophilic meningitis. A. cantonensis infection is an emergent disease causing permanent neurological injury or even death when not diagnosed and treated promptly. Usually, human infection occurs through ingestion of food contaminated by intermediated hosts or the third stage larvae of A. cantonensis. Indicators for diagnosis include clinical signs of meningitis; contact history, such as that from eating raw or improperly cooked intermediated hosts or contaminated vegetables; and cerebrospinal fluid (CSF) eosinophilia. However, diagnosis is now primarily defined through polymerase chain reaction (PCR) assay of CSF or serum.
CASE REPORT: A 66-year-old homeless man with unclear exposure history presented with fever and conscious change. The initial hemogram showed eosinophilia without neutrophilic leukocytosis. Non-contrast computed tomography (CT) and magnetic resonance imaging (MRI) of the head revealed no evidence of stroke. A lumbar puncture was performed and showed eosinophilic meningitis. The patient was ultimately diagnosed through PCR and sequencing for A. cantonensis infection, and dexamethasone treatment was started immediately. Although his general condition improved after dexamethasone treatment, his mental status did not improve completely.
CONCLUSIONS: Our report highlights the importance of applying molecular techniques in diagnosis of angiostrongylosis, especially in individuals who have unknown contact history.
Keywords: angiostrongyliasis, Angiostrongylus cantonensis, Meningitis, Polymerase Chain Reaction, Aged, Animals, Humans, Male, Dexamethasone, Eosinophilia, Leukocytosis
Background
Case Report
A 66-year-old homeless man experiencing fever, dizziness, cough, and lethargy for 1 day visited our hospital. Upon arrival, the patient presented with a fever of 39.2°C, which subsequently subsided after he took acetaminophen. The hemo-gram showed eosinophilia without neutrophilic leukocytosis (white cell count 9090 mm3 with 9% eosinophils and 63.9% neutrophils). The COVID-19 PCR test was negative. Following these findings, the patient was discharged. However, the following day, he returned to our ED complaining of chest tightness, headache, and fever. His cardiac enzyme readings were within their normal ranges, and his electrocardiogram findings indicated no myocardial infarction. Eosinophilia without neutrophilic leukocytosis persisted in the hemogram. Blood cultures yielded negative results, and urinalysis was negative for leukocyte esterase and nitrites. Biochemical blood profiles showed elevated creatine kinase (CK) level and myoglobin level. Follow-up biochemical blood profiles revealed decreased CK and myoglobin levels, and he was discharged with improved symptoms. However, he returned to our ED on the same day for a resurgence of fever reaching 37.9°C. His consciousness then deteriorated. Since we were unable to reach any of his family members and his consciousness dramatically deteriorated, the contact history remained unclear.
On examination, he had a Glasgow Coma Scale score of E1V2M4, with spontaneous movement in his arms and legs. His pupils were equal, round, and mildly reactive to light, with a decrease in diameter from 4 to 3 mm. The remainder of the examination revealed normal findings. The white cell count was 10 150 mm3 with 12.5% eosinophils, the blood level of sodium was 128 mmol/L, his C-reactive protein level was 0.82 mg/dL, and the CK level was 457 U/L. His hematocrit results, hemoglobin count, other white cell differential count, platelet count, and anion gap were normal. Similarly, the blood levels of potassium, ethyl alcohol, ammonia, glucose, lactate, and troponin-I were all normal. Additionally, the results of renal and liver function tests were also normal. The urine toxicologic screening was negative. Non-contrast computed tomography (CT) and magnetic resonance imaging (MRI) of the head revealed no evidence of stroke. Lumbar puncture revealed clear CSF and an opening pressure of 24 cm of water. The CSF white blood cell count was 373 cells/mL, and eosinophils were predominant (54%); the glucose level was 107.2 mg/dL; and the protein level was 55 mg/dL. The corresponding serum glucose level was 176 mg/dL. The CSF PCR assays were negative for of cytomegalovirus, enterovirus, herpes simplex virus 1, herpes simplex virus 2, human herpesvirus 6, human parechovirus, varicella zoster virus, Haemophilus influenzae,
Throughout hospitalization, CSF specimen was sent to the Taiwan Centers for Disease Control for testing of leptospirosis, Q fever, and scrub typhus. The results of these tests were negative. Subsequently, we began treatment with intravenous ceftriaxone and doxycycline. However, the patient’s level of consciousness did not improve despite antibiotic treatment. Because the CSF cell count remained eosinophil predominant (36%), we decided to survey
The CSF sample from this patient was tested by standard PCR. A 213 base pairs amplicon of the mitochondrial cytochrome oxidase subunit 1 gene was amplified and sequenced. Mixture for PCR amplification consisted of 0.2 μM CO1ACF7 primer (5’-TGC CTG CTT TTG GGA TTG TTA GAC-3’), 0.2 μM CO1ACR7 primer (5’-TCA CTC CCG TAG GAA CCG CA-3’), the KAPA2G Fast HotStart ReadyMix (KAPA Biosystems, Cape town, South Africa), and 5 μL of the DNA sample in the DNAzol DIRECT solution (Molecular Research Center Inc., Ohio, U. S. A.) in a total volume of 50 μL [6]. Following an initial incubation at 95°C for 10 minutes to activate the thermoactive polymerase, the PCR program was as follows: 94°C for 30 seconds, 50°C for 30 seconds, and 72°C for 30 seconds, repeated for 45 cycles. The PCR amplicons were then subjected to DNA sequencing, later compared to National Center for Biotechnology Information (NCBI) database. Both PCR and sequencing were performed in the biosafety cabinet with BSL 2 facilities of Medical Science and Technology Building of Veterans General Hospital to ensure the safety and security of the personnel. Figure 1 demonstrates the CSF PCR results, show a positive band at 213 bp, revealing positivity for
Brain MRI revealed increased signal intensity in the bilateral periventricular and subcortical white matter on T2-weighted imaging (Figure 3). Susceptibility-weighted imaging (SWI) revealed linear hypointensities over bilateral cerebral hemispheres, suggesting small arterial occlusion compatible with larvae occlusion in the small arteries (Figure 4) [7].
After
Discussion
Eosinophilic meningitis is a rare but potentially fatal disease if not promptly diagnosed. The etiology of eosinophilic meningitis can be divided into non-parasitic and parasitic. Non-parasitic etiology, which is rare, includes fungal infection, such as coccidioidomycosis and cryptococcosis, hypereosinophilic syndromes, and neoplastic diseases. Among the parasitic causes of eosinophilic meningitis,
The diagnosis of
The management of cerebral angiostrongyliasis primarily involves supportive measures, with the infection typically resolving spontaneously. In severe cases, corticosteroids and repeated lumbar puncture is recommended to control inflammation and decrease intracranial pressure. The efficacy and safety of anthelmintic therapy, such as benzimidazoles and ivermectin, remain controversial, as it can exacerbate neurological symptoms by provoking an inflammatory reaction as the worms die off [4,7,8].
Patients with neurological symptoms may undergo head CT or MRI to exclude other non-parasitic causes. Head CT without focal lesions is a sign of neuroangiostrongyliasis rather than gnathostomiasis or neurocysticercosis. A study reported that MRI helps to distinguish between different parasitic causes of eosinophilic meningitis [10].
Conclusions
This report highlights that when assessing a conscious impaired patient with unknown contact history, eosinophilia, or eosinophilic meningitis, clinicians must consider
Figures
References:
1.. Johnston DI, Dixon MC, Elm JL, Review of cases of angiostrongyliasis in Hawaii, 2007–2017: Am J Trop Med Hygiene, 2019; 101; 608-16
2.. Tsai HC, Chen YS, Yen CM: Hawai’i J Med Public Health, 2013; 72; 26-27
3.. Dard C, Tessier E, Nguyen D: Parasite, 2020; 27; 31
4.. Ansdell V, Kramer KJ, McMillan JK, Guidelines for the diagnosis and treatment of neuroangiostrongyliasis: Updated recommendations: Parasitology, 2021; 148; 227-33
5.. Qvarnstrom Y, da Silva ACA, Teem JL, Hollingsworth R: Appl Environ Microbiol, 2010; 76; 5287-89
6.. Qvarnstrom Y, Xayavong M, da Silva ACA: Am J TropMed Hygiene, 2016; 94; 176-81
7.. Ansdell V, Wattanagoon Y: Curr Opin Infect Dis, 2018; 31; 399-408
8.. Mathison BA, Pritt BS, Medical parasitology: Henry’s clinical diagnosis and management by laboratory methods, 2021; 1290-351, Elsevier
9.. Melo LCVd, Souza FCRd, Baccin AdO: Mem Inst Oswaldo Cruz, 2022; 117; e220086
10.. Kanpittaya J, Sawanyawisuth K, Intapan PM, A comparative study of neuroimaging features between human neuro-gnathostomiasis and angiostrongyliasis: Neurol Sci, 2012; 33; 893-98
11.. Tsai HC, Liu YC, Kunin CM: Am J Trop Med Hygiene, 2003; 68; 281-85
12.. Jin E, Ma D, Liang Y: Clin Radiol, 2005; 60; 242-50
13.. Tsai HC, Tseng YT, Yen CM: Vector-Borne Zoonot Dis, 2012; 12; 161-66
14.. Nalini A, Ramakrishna A, Dekumoy P: Neurol India, 2013; 61; 414-18
15.. Chiong F, Lloyd AR, Post JJ, Severe eosinophilic meningoencephalitis secondary to suspected neuroangiostrongyliasis with a good clinical outcome: Case Rep Infect Dis, 2019; 2019; 4037196
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