Encephalitozoon cuniculi Genotype I as a Causative Agent of Brain Abscess in an Immunocompetent Patient

Abstract

A brain abscess caused by Encephalitozoon cuniculi genotype I together with Streptococcus intermedius occurred in a patient without major immunocompromise and with diabetes. The distinguishing clinical signs were hemiparesis and epilepsy. The microsporidium was observed in the abscess aspirate, and its specific DNA was also detected in stool and urine. The patient was successfully treated with albendazole and mebendazole. CASE REPORTA 56-year-old male patient with a history of myocardial infarction years ago, recently diagnosed with type II diabetes mellitus treated with metformin and hypertension treated with antihypertensives, was transferred from a county referral hospital with a 5-day history of illness that after two episodes of loss of conscience with generalized seizures left him with residual hemiparesis on the left side and severe cognitive impairment, along with a temperature of 39.5°C. By occupation, he is a groundskeeper in city parks. Prior to admission he spent most of his work time mowing lawns.The initial cranial CT scan did not detect any pathology except for some fluid in his paranasal sinuses-right-sided frontal, ethmoid, and maxillary sinusitis. Lumbar puncture revealed a mild elevation in protein (99 mg/dl) and leukocytes (14 cells/l, 63% segmented neutrophils and 37% lymphocytes) (corresponding to the initial stage of aseptic meningitis). General markers of systemic inflammation (leukocytes, C-reactive protein [CRP], and procalcitonin in serum) did not suggest bacterial infection. The preliminary diagnosis was viral encephalitis, most likely tick-borne, complicated by sinusitis.The initial therapy included diazepam, phenytoin, omeprazole, dexamethasone, mannitol, tiapride, and empirical amoxicillin clavulanate due to the fluid present in the sinuses. Due to the progression of left-sided regional seizures to generalized seizures and to status epilepticus, he was intubated 5 days after admission and mechanically ventilated for 3 days. After extubation, his state of conscience improved to Glasgow coma scale 15, with no subsequent seizures, and the patient manifested only residual weakness of his left hand. His temperature normalized and antibiotics were discontinued after 10 days. CRP and procalcitonin never exceeded 35 mg/liter and 0.2 ng/ml, respectively.

Limited effect of adaptive immune response to control encephalitozoonosis

“…Microsporidiosis is an emerging infectious disease with a rapidly broadening clinical spectrum including gastrointestinal, pulmonary, nasal, ocular, muscular, cerebral and systemic infections. Microsporidiosis should be considered not only in the differential diagnosis of HIV‐related symptomatic disease of virtually all organ systems affected, but also in immunocompetent individuals as causative agents of diseases with unknown aetiology …”

“…Microsporidiosis should be considered not only in the differential diagnosis of HIV-related symptomatic disease of virtually all organ systems affected, 24 but also in immunocompetent individuals as causative agents of diseases with unknown aetiology. 25,26 In recent decades, intense study of host immunity against microsporidia has been enabled by the establishment of murine models that successfully reproduce the different courses of infection observed in hosts of varying immunological status. Although the roles of both humoral and cellular immunity were previously demonstrated, the central role of cell-mediated immunity, especially that of CD8 + cytotoxic T lymphocytes, in the defence against microsporidial infection has been recently confirmed with adoptive transfer experiments.…”

Latent Microsporidiosis Caused by Encephalitozoon cuniculi in Immunocompetent Hosts: A Murine Model Demonstrating the Ineffectiveness of the Immune System and Treatment with Albendazole

“…Latent microsporidiosis also can be dangerous for the carrier himself if undergoing chemotherapy for cancer or other immunosuppressive therapies. In addition, microsporidia can also cause serious disease in immunocompetent hosts [45].…”

Microsporidiosis

“…A. algerae primarily infects mosquitoes and this finding suggests that vectorborne transmission of microsporidiosis is possible. A patient with diabetes and a history of myocardial infarction and hypertension was reported with a brain abscess due to Streptococcus intermedius and E. cuniculi genotype I [34*], and endocarditis associated with E. cuniculi was reported in a patient whose pacemaker had been replaced 3 months earlier [35]. As awareness grows and diagnostic methods are applied to deliberately examine immune compromised individuals for microsporidia, it is expected that the number of case reports of opportunistic microsporidioses in such patients will continue to increase.…”