Fulminant Amebic Encephalitis in a Kidney Transplant Patient

Free-living ameba is an opportunistic protozoan and is ubiquitous in nature. Amebic encephalitis (AE) is an almost uniformly fatal infection in immunocompromised hosts despite multidrug combination therapy. Naegleria and Acanthamoeba are known species that cause rare and almost always fatal AE. We report a case of AE in a kidney transplant recipient, who presented 1 month after transplantation with headache, aphasia, and convulsions. Magnetic resonance imaging (MRI) of the brain showed hyperintense lesions in the subcortical white matter of the left frontal and left temporal lobes. Cerebrospinal fluid (CSF) polymerase chain reaction (PCR) was negative for viruses, bacteria, tuberculosis, and Cryptococcus . The patient was started on empiric amphotericin, vancomycin, meropenem, voriconazole, co-trimoxazole, and steroids. A repeat MRI with spectroscopy performed on day 3 of presentation showed an increase in the size of lesions with microhemorrhages. Brain biopsy confirmed the diagnosis of trophozoite and cyst forms of free-living amebae. Differentiation of species could not be ascertained as PCR was not done. The patient was treated with miltefosine, azithromycin, and moxifloxacin while continuing the previous empiric therapy. He succumbed within 8 days of presentation. The case reports of free-living AE in transplantation, available in the literature, with their clinical presentation, CSF and imaging findings, diagnosis and treatment, and outcome were reviewed, with the conclusion that these infections tend to be fulminant with high mortality in transplant patients, and early tissue diagnosis is required, as CSF and imaging findings are inconclusive.