ABSTRACT
An indirect fluorescent antibody test (IFAT) for detection of Toxoplasma gondii infection was validated using serum from 77 necropsied southern sea otters (Enhydra lutris nereis) whose T. gondii infection status was determined through immunohistochemistry and parasite isolation in cell culture. Twenty-eight otters (36%) were positive for T. gondii by immunohistochemistry or parasite isolation or both, whereas 49 (64%) were negative by both tests. At a cutoff of 1:320, combined values for IFAT sensitivity and specificity were maximized at 96.4 and 67.3%, respectively. The area under the receiver-operating characteristic curve for the IFAT was 0.84. A titer of 1:320 was used as cutoff when screening serum collected from live-sampled sea otters from California (n = 80), Washington (n = 21), and Alaska (n = 65) for T. gondii infection. Thirty-six percent (29 out of 80) of California sea otters (E. lutris nereis) and 38% (8 out of 21) of Washington sea otters (E. lutris kenyoni) were seropositive for T. gondii, compared with 0% (0 out of 65) of Alaskan sea otters (E. lutris kenyoni).
Subject(s)
Antibodies, Protozoan/blood , Fluorescent Antibody Technique, Indirect/veterinary , Otters/parasitology , Toxoplasma/immunology , Toxoplasmosis, Animal/epidemiology , Alaska/epidemiology , Animals , Brain/parasitology , California/epidemiology , Female , Fluorescent Antibody Technique, Indirect/methods , Immunohistochemistry/veterinary , Male , Otters/blood , ROC Curve , Sensitivity and Specificity , Seroepidemiologic Studies , Statistics, Nonparametric , Toxoplasma/growth & development , Toxoplasmosis, Animal/immunology , Toxoplasmosis, Animal/parasitology , Washington/epidemiologyABSTRACT
OBJECTIVE: To determine the effects of petroleum exposure on hematologic and clinical biochemical results of mink and to identify variables that may be useful for making management decisions involving sea otters (Enhydra lutris) that have been exposed to oil in their environment. ANIMALS: 122 American mink (Mustela vison). PROCEDURES: Mink were exposed once to a slick of oil (Alaskan North Slope crude oil or bunker C fuel oil) on seawater or via low-level contamination of their daily rations. RESULTS: In the acute phase of exposure, petroleum directly affected RBC, WBC, neutrophil, and lymphocyte counts, fibrinogen, sodium, calcium, creatinine, total protein, and cholesterol concentrations, and alanine transaminase, creatine kinase, alkaline phosphatase, and gamma-glutamyltransferase activities. Aspartate transaminase, alkaline phosphatase, gamma-glutamyltransferase, and lactate dehydrogenase activities and cholesterol concentration also varied as a result of chronic low-level contamination of feed. CONCLUSIONS AND CLINICAL RELEVANCE: Our results are in agreement with reports that attribute increased alanine transaminase and alkaline phosphatase activities and decreased total protein concentration to petroleum exposure in sea otters during an oil spill. Sodium, calcium, creatinine, cholesterol, and lactate dehydrogenase may be valuable variables to assess for guidance during initial treatment of sea otters exposed to oil spills as well as for predicting which petroleum-exposed sea otters will reproduce following an oil spill. Measurement of these variables should aid wildlife professionals in making decisions regarding treatment of sea otters after oil spills.