Indirect fluorescent antibody testing of cerebrospinal fluid for diagnosis of equine protozoal myeloencephalitis

Paulo C. Duarte, Eric D. Ebel, Josie Traub-Dargatz, William D Wilson, Patricia A Conrad, Ian Gardner

Research output: Contribution to journalArticle

15 Citations (Scopus)

Abstract

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 pre-test probability values were estimated. Post-test probabilities were compared for use of a serum-CSF test cobination, 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 ≤ 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.

Original languageEnglish (US)
Pages (from-to)869-876
Number of pages8
JournalAmerican Journal of Veterinary Research
Volume67
Issue number5
DOIs
StatePublished - May 2006

Fingerprint

equine protozoal myeloencephalitis
Encephalomyelitis
cerebrospinal fluid
antibody detection
Horses
Cerebrospinal Fluid
Antibodies
Serum
testing
Sarcocystis
Nervous System Diseases
antibodies

ASJC Scopus subject areas

  • veterinary(all)

Cite this

Indirect fluorescent antibody testing of cerebrospinal fluid for diagnosis of equine protozoal myeloencephalitis. / Duarte, Paulo C.; Ebel, Eric D.; Traub-Dargatz, Josie; Wilson, William D; Conrad, Patricia A; Gardner, Ian.

In: American Journal of Veterinary Research, Vol. 67, No. 5, 05.2006, p. 869-876.

Research output: Contribution to journalArticle

@article{9ce2dac2c04447f1b192481a7cfa66bb,
title = "Indirect fluorescent antibody testing of cerebrospinal fluid for diagnosis of equine protozoal myeloencephalitis",
abstract = "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 pre-test probability values were estimated. Post-test probabilities were compared for use of a serum-CSF test cobination, 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 ≤ 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.",
author = "Duarte, {Paulo C.} and Ebel, {Eric D.} and Josie Traub-Dargatz and Wilson, {William D} and Conrad, {Patricia A} and Ian Gardner",
year = "2006",
month = "5",
doi = "10.2460/ajvr.67.5.869",
language = "English (US)",
volume = "67",
pages = "869--876",
journal = "American Journal of Veterinary Research",
issn = "0002-9645",
publisher = "American Veterinary Medical Association",
number = "5",

}

TY - JOUR

T1 - Indirect fluorescent antibody testing of cerebrospinal fluid for diagnosis of equine protozoal myeloencephalitis

AU - Duarte, Paulo C.

AU - Ebel, Eric D.

AU - Traub-Dargatz, Josie

AU - Wilson, William D

AU - Conrad, Patricia A

AU - Gardner, Ian

PY - 2006/5

Y1 - 2006/5

N2 - 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 pre-test probability values were estimated. Post-test probabilities were compared for use of a serum-CSF test cobination, 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 ≤ 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.

AB - 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 pre-test probability values were estimated. Post-test probabilities were compared for use of a serum-CSF test cobination, 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 ≤ 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.

UR - http://www.scopus.com/inward/record.url?scp=33744495993&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33744495993&partnerID=8YFLogxK

U2 - 10.2460/ajvr.67.5.869

DO - 10.2460/ajvr.67.5.869

M3 - Article

C2 - 16649923

AN - SCOPUS:33744495993

VL - 67

SP - 869

EP - 876

JO - American Journal of Veterinary Research

JF - American Journal of Veterinary Research

SN - 0002-9645

IS - 5

ER -