RESUMO
BACKGROUND: Encephalitis caused by a free-living amoeba is relatively rare and usually fatal. This is because the diagnosis is often made late and treatment is difficult. CASE DESCRIPTION: A 41-year-old patient with a previous history including kidney transplant was admitted with clinical symptoms of encephalitis. Brain imaging showed a number of hypodense regions, which were possibly abscesses. Although an infectious cause seemed probable, even the most extensive antimicrobial treatment was ineffective. The cause was not found until 2 months after the patient's death: infection with Balamuthia mandrillaris. A PCR test was used to detect this amoeba. CONCLUSION: This case study describes the first patient in the Netherlands to be diagnosed with granulomatous amoebic encephalitis caused by B. mandrillaris. An amoeba may be the cause of encephalitis with either a fulminant course or with a gradual increase of symptoms, without conventional anti-infective therapy being effective.