title: Neurological disease in wild loggerhead sea turtles Caretta caretta.
abstract: Beginning in October 2000, subadult loggerhead sea turtles Caretta caretta showing clinical signs of a neurological disorder were found in waters off south Florida, USA. Histopathology indicated generalized and neurologic spirorchiidiasis. In loggerhead sea turtles (LST) with neurospirorchiidiasis, adult trematodes were found in the meninges of the brain and spinal cord of 7 and 3 affected turtles respectively, and multiple encephalic intravascular or perivascular eggs were associated with granulomatous or mixed leukocytic inflammation, vasculitis, edema, axonal degeneration and occasional necrosis. Adult spirorchiids were dissected from meningeal vessels of 2 of 11 LST brains and 1 of 10 spinal cords and were identified as Neospirorchis sp. Affected LST were evaluated for brevetoxins, ciguatoxins, saxitoxins, domoic acid and palytoxin. While tissues from 7 of 20 LST tested positive for brevetoxins, the levels were not considered to be in a range causing acute toxicosis. No known natural (algal blooms) or anthropogenic (pollutant spills) stressors co-occurred with the turtle mortality. While heavy metal toxicosis and organophosphate toxicosis were also investigated as possible causes, there was no evidence for their involvement. We speculate that the clinical signs and pathologic changes seen in the affected LST resulted from combined heavy spirorchiid parasitism and possible chronic exposure to a novel toxin present in the diet of LST.
authors.affiliation: College of Veterinary Medicine, University of Florida, Gainesville, Florida 32610, USA. jacobsone@mail.vetmed.ufl.edu
authors.forename: Elliott R
authors.initials: ER
authors.lastname: Jacobson
authors.forename: Bruce L
authors.initials: BL
authors.lastname: Homer
authors.forename: Brian A
authors.initials: BA
authors.lastname: Stacy
authors.forename: Ellis C
authors.initials: EC
authors.lastname: Greiner
authors.forename: Nancy J
authors.initials: NJ
authors.lastname: Szabo
authors.forename: Cheryl L
authors.initials: CL
authors.lastname: Chrisman
authors.forename: Francesco
authors.initials: F
authors.lastname: Origgi
authors.forename: Sadie
authors.initials: S
authors.lastname: Coberley
authors.forename: Allen M
authors.initials: AM
authors.lastname: Foley
authors.forename: Jan H
authors.initials: JH
authors.lastname: Landsberg
authors.forename: Leanne
authors.initials: L
authors.lastname: Flewelling
authors.forename: Ruth Y
authors.initials: RY
authors.lastname: Ewing
authors.forename: Richie
authors.initials: R
authors.lastname: Moretti
authors.forename: Susan
authors.initials: S
authors.lastname: Schaf
authors.forename: Corinne
authors.initials: C
authors.lastname: Rose
authors.forename: Douglas R
authors.initials: DR
authors.lastname: Mader
authors.forename: Glenn R
authors.initials: GR
authors.lastname: Harman
authors.forename: Charles A
authors.initials: CA
authors.lastname: Manire
authors.forename: Nancy S
authors.initials: NS
authors.lastname: Mettee
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Mizisin
authors.forename: G Diane
authors.initials: GD
authors.lastname: Shelton
mesh_terms: D000818:Animals; D001921:Brain / Q000469:parasitology; D002802:Cholinesterases / Q000032:analysis; D005260:Female; D005431:Florida; D007668:Kidney / Q000737:chemistry; D008099:Liver / Q000737:chemistry; D008297:Male; D008387:Marine Toxins / Q000032:analysis; D019216:Metals, Heavy / Q000032:analysis; D018482:Muscle, Skeletal / Q000737:chemistry / Q000473:pathology; D009422:Nervous System Diseases / Q000469:parasitology / Q000473:pathology / Q000662:veterinary*; D035964:Oxocins / Q000032:analysis; D012584:Sciatic Nerve / Q000473:pathology; D014200:Trematoda / Q000302:isolation & purification* / Q000472:pathogenicity; D014201:Trematode Infections / Q000473:pathology / Q000662:veterinary*; D014426:Turtles / Q000469:parasitology*; D000095702:Polyether Toxins
chemical_list: D002802:Cholinesterases; D008387:Marine Toxins; D019216:Metals, Heavy; D035964:Oxocins; C053342:brevetoxin; D000095702:Polyether Toxins