Objective-To assess the use of CSF testing with an indirect fluorescent antibody test (IFAT) for diagnosis of equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona. Sample Population-Test results of 428 serum and 355 CSF samples from 182 naturally exposed, experimentally infected, or vaccinated horses. Procedure-EPM was diagnosed on the basis of histologic examination of the CNS. Probability distributions were fitted to serum IFAT results in the EPM+ and EPM- horses, and correlation between serum and CSF results was modeled. Pairs of serum-CSF titers were generated by simulation, and titer-specific likelihood ratios and post-test probabilities of EPM at various pretest probability values were estimated. Post-test probabilities were compared for use of a serum-CSF test combination, a serum test only, and a CSF test only. Results-Post-test probabilities of EPM increased as IFAT serum and CSF titers increased. Post-test probability differences for use of a serum-CSF combination and a serum test only were less than or equal to 19% in 95% of simulations. The largest increases occurred when serum titers were from 40 to 160 and pre-test probabilities were from 5% to 60%. In all simulations, the difference between pre- and post-test probabilities was greater for a CSF test only, compared with a serum test only. Conclusions and Clinical Relevance-CSF testing after a serum test has limited usefulness in the diagnosis of EPM. A CSF test alone might be used when CSF is required for other procedures. Ruling out other causes of neurologic disease reduces the necessity of additional EPM testing.

acute Sarcocystis cruzi infection in calves (exper.), hematologic studies support claim that anemia is an extravascular hemolytic event, probably with immunologic basis; coagulation studies indicate that endothelial S. cruzi schizonts may cause endothelial damage, resulting in coagulation abnormalities that include disseminated intravascular coagulation

Sarcocystis suicanis, Georgia isolate, pigs (exper.), pathology, reduced growth rate of host

Eight bovine hearts with lesions of eosinophilic myositis (EM) and 2 bovine hearts without EM lesions were collected at slaughter. Blood samples from these 10 hearts, and the heart of a newborn calf also were collected. Histologically, Sarcocystis cruzi was identified in the 8 hearts with EM lesions and the 2 hearts without EM lesions, but not in the heart of the newborn calf. Serum was harvested from the 10 blood samples and was used in homologous, modified, passive cutaneous anaphylaxis test. Antigen was prepared from S cruzi bradyzoites isolated from the 2 hearts without EM lesions. Serum samples from the 8 cattle with EM lesions reacted positively to S cruzi antigen. When heat-inactivated IgE in serum (56 C for 4 hours) was used, all passive cutaneous anaphylaxis responses were considered negative. Using ELISA, serum IgE concentrations from the 10 cattle with and without EM lesions were 2.2 to 9 U/ml. As determined by radial immunodiffusion, IgM concentrations were 80 to 215 mg/dl. Immunoglobulin G concentrations were 420 to 2,050 mg/dl, but most were less than or equal to 1,700 mg/dl. Immunoglobin A concentrations were 0 to 62 mg/dl; 1 steer with EM lesions had 0 mg/dl. Double-gel immunodiffusion confirmed the presence of Sarcocystis-specific precipitating antibodies. Sera from the 10 cattle with and without EM lesions formed at least 1 precipitin band.

Sarcocystis capracanis, pregnant dairy goats immunized with a subclinical dose of sporocysts and subsequently challenged with lethal doses, concluded that: i) subclinical dose given in early pregnancy can cause fetal death without causing clinical disease in doe; ii) abortion can occur prior to development of 2nd-generation meronts; and iii) Sarcocystis-induced immunity is impaired during pregnancy

Sarcocystis spp. in infected meat from ox, sheep, goats, moose, elk, and mule deer fed to raccoons, none shed Sarcocystis sporocysts in feces

sarcocystosis causing death in calf immediately after birth, rosette and palisade configurations of merozoites in schizonts observed in histologic sections of gray and white matter from cerebrum; encephalitis, to lesser extent meningitis, and necrosis of cerebrum, cerebellum, and brain stem; calf's dam probably was exposed to infective cysts in feed or water contaminated by feces from carnivores

Sarcocystis odocoileocanis, S. odoi n. sp., and Sarcocystis sp. found in muscles of white-tailed deer, measurements, ultrastructure; cat fed Sarcocystis-infected meat from deer shed sporocysts 24 days later which probably belonged to S. odoi n. sp.

Sarcocystis cruzi, calves fed sporocysts of 2 different isolates from coyotes, number of merozoites in peripheral blood, duration of parasitemia, and extent of multiplication of merozoites

Sarcocystis cruzi, newborn calves (exper.), correlation of development of Sarcocystis with the resulting lesions