Open AccessProtozoal coinfection in horses with equine protozoal myeloencephalitis in the eastern United States
Author(s) -
Schale Sarah,
Howe Daniel,
Yeargan Michelle,
Morrow Jennifer K.,
Graves Amy,
Johnson Amy L.
Publication year - 2018
Publication title -
journal of veterinary internal medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.356
H-Index - 103
eISSN - 1939-1676
pISSN - 0891-6640
DOI - 10.1111/jvim.15127
Subject(s) - toxoplasma gondii , medicine , serology , titer , horse , coinfection , cerebrospinal fluid , sarcocystis , seroprevalence , toxoplasmosis , neospora , protozoan infection , pleocytosis , immunology , neospora caninum , antibody , myelopathy , pathology , biology , parasite hosting , virus , spinal cord , paleontology , psychiatry , world wide web , computer science
Background Infection by 2 or more protozoa is linked with increased severity of disease in marine mammals with protozoan encephalitis. Hypothesis/Objectives To assess whether horses with equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona also have evidence of infection with Neospora hughesi or Toxoplasma gondii . We hypothesized that horses with EPM would be more likely than horses with cervical vertebral stenotic myelopathy (CVSM) to be positive for antibodies to multiple protozoan parasites. Animals One hundred one horses with neurologic disease: 49 with EPM and 52 with CVSM. Methods Case review. Archived serum and cerebrospinal fluid (CSF) from 101 horses were examined. Inclusion criteria included neurologic disease, antemortem or postmortem diagnosis of EPM or CVSM, and availability of serological results or archived samples for testing. Additional testing for antibodies was performed on serum for T. gondii , as well as serum and CSF for N. hughesi . Results Horses with EPM were more likely than horses with CVSM to have positive immunologic results for S. neurona on serum (95.9% versus 76.9%, P = .0058), CSF (98.0% versus 44.2%, P < .00001), and serum : CSF titer ratio (91.8% versus 0%, P < .00001). Positive results for Neospora and Toxoplasma were uncommon, with total seroprevalence rates of 12.9% and 14.9%, respectively. The proportions of EPM cases testing positive for Neospora and Toxoplasma (16% and 12%) were not different from the proportions of CVSM cases testing positive (10% and 17%, P = .31 and .47, respectively). Conclusion Results do not indicate an important role for protozoal coinfection in EPM in the eastern United States.