Abstract
BACKGROUND: Brain infection by free-living amoebae can present as granulomatous amoebic encephalitis if caused by Acanthamoeba spp. or Balamuthia mandrillaris, or as primary amoebic meningoencephalitis if caused by Naegleria fowleri, the latter with high morbidity and mortality. Diagnosis is made by studying cerebrospinal fluid or tissue samples by direct microscopy, culture, polymerase chain reaction, or immunofluorescence. There is no specific treatment, and there are only reports of success with prolonged use of combined drugs. CASES DESCRIPTION: We present five cases with a diagnosis of brain infection by free-living amoebae treated at the Hospital Almenara. The patients received surgical treatment, and four of them also received antiparasitic treatment; in one case, the diagnosis was post-mortem. Antiparasitic treatment consisted of a combination of miltefosine, voriconazole, and albendazole mainly, with an average time of 4.8 months. All cases were diagnosed after the initial surgery, and two patients died. Diagnosis in all cases was by direct microscopy, but typing of the free-living amoeba involved was not possible. CONCLUSION: Brain infection by free-living amoebae is a disease with high morbimortality, which requires early diagnosis for a better prognosis if long-term combined treatment is established.