{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,31]],"date-time":"2026-01-31T01:32:47Z","timestamp":1769823167474,"version":"3.49.0"},"reference-count":49,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2025,3,19]],"date-time":"2025-03-19T00:00:00Z","timestamp":1742342400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Vet. Sci."],"abstract":"<jats:p><jats:italic>Balamuthia mandrillaris<\/jats:italic> is an amoeba that can cause granulomatous amoebic encephalitis (GAE) as well as lung and skin infections in both humans and animals. Studies on <jats:italic>B. mandrillaris<\/jats:italic>-related GAE cases have increased in recent years. This amoeba has been identified as a cause of encephalitis and death in several non-human primates. In this study, we report a case of a 4-year-old female Bornean orangutan (<jats:italic>Pongo pygmaeus<\/jats:italic>) in a zoological center that exhibited neurological symptoms for several days. After unsuccessful treatments and a worsening in her condition, euthanasia was deemed necessary. Additionally, we describe the case of a 4-year-old male chimpanzee (<jats:italic>Pan troglodytes verus<\/jats:italic>) who died suddenly in a different zoo. Postmortem analysis revealed brain lesions with multiple hemorrhages, oedema, and inflammation in various organs in both cases. Histology showed the presence of <jats:italic>B. mandrillaris<\/jats:italic> trophozoites in necrotic and inflamed brain tissues, consistent with granulomatous amoebic meningoencephalitis. The diagnosis was confirmed using a multiplex qPCR assay on brain tissue samples from both animals water and soil samples from the chimpanzee\u2019s and orangutan\u2019s enclosure tested positive for <jats:italic>B. mandrillaris<\/jats:italic> DNA by qPCR, confirming environmental exposure. An immunofluorescent antibody (IFA) assay detected <jats:italic>B. mandrillaris<\/jats:italic> in chimpanzee brain slices. According to the authors\u2019 knowledge, this report documents the first known cases of <jats:italic>Balamuthia<\/jats:italic> amoebic encephalitis in non-human primates in Spain and the first case in <jats:italic>Pan troglodytes verus<\/jats:italic>.<\/jats:p>","DOI":"10.3389\/fvets.2025.1534378","type":"journal-article","created":{"date-parts":[[2025,3,19]],"date-time":"2025-03-19T13:43:37Z","timestamp":1742391817000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":2,"title":["Fatal amoebic meningoencephalitis caused by Balamuthia mandrillaris in Pongo pygmaeus and first case report in Pan troglodytes verus"],"prefix":"10.3389","volume":"12","author":[{"given":"Rub\u00e9n 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