J. Christian Franson
Erik K. Hofmeister
Gail H. Collins
Robert J. Dusek
2017-02-23
Seroprevalence of West Nile virus in feral horses on Sheldon National Wildlife Refuge, Nevada, United States 2004-2006, 2008 and 2009
The data are provided as a spreadsheet and associated data dictionary in both Microsoft Excel workbook (.xlsx, v. 2010) and comma separate values (.csv) text formats. A help document for defining terms in the data dictionary is provided in text format.
Reston, VA
U. S. Geological Survey
https://dx.doi.org/10.5066/F7S75DDD
J. Christian Franson
Erik K. Hofmeister
Gail H. Collins
Robert J. Dusek
2011
Seroprevalence of West Nile Virus in Feral Horses on Sheldon National Wildlife Refuge, Nevada, United States
Analyzed/summarized
American Journal of Tropical Medicine and Hygiene
The American Society of Tropical Medicine and Hygiene
https://doi.org/10.4269/ajtmh.2011.10-0467
The authors screened 1,397 feral horses (Equus caballus) on Sheldon National Wildlife Refuge, Nevada, United States, for IgM and IgG against flavivirus during 2004-2006, 2008, and 2009. Positive serum samples were tested for neutralizing antibodies to West Nile virus (WNV) and St. Louis encephalitis virus (SLEV). One animal was positive for antibody against WNV in 2004, but all others tested in 2004-2006 were negative. In 2008 and 2009, the authors found evidence of increasing seropositive horses with age, whereas seroprevalence of WNV decreased from 19% in 2008 to 7.2% in 2009. No horses were positive for antibody against SLEV. Being unvaccinated, feral horses can be useful for WNV surveillance.
Little is known about West Nile virus (WNV) in non-domestic (i.e., wild or feral) horses (Equus caballus) beyond serologic surveys that have reported WNV antibody prevalence from < 1% to 63% of animals tested. The authors screened 1,397 feral horses (Equus caballus) on Sheldon National Wildlife Refuge, Nevada, United States, for IgM and IgG against flavivirus during 20042006, 2008, and 2009.Horses are considered dead end hosts of WNV, but wild and feral horses, being unvaccinated, can be useful in WNV surveillance.
2004
2009
ground condition
None planned
-119.55322265507
-118.46008300668
41.979585644306
41.569924429412
Sheldon National Wildlife Refuge
USGS Thesaurus
viruses
zoonotic disease
wildlife disease
disease vectors
wildlife
feral horse
None
West Nile virus
antibody
serology
USGS Metadata Identifier
USGS:5633beede4b048076347f023
Geographic Names Information System
Sheldon National Wildlife Refuge, Nevada, USA
None
None
None
None
none
Acknowledgement of National Wildlife Health Center, U. S. Geological Survey and/or its partners is requested in products derived from these data.
J. Christian Franson
U. S. Geological Survey
mailing and physical
6006 Schroeder Rd
Madison
WI
53711
USA
608-270-2444
jfranson@usgs.gov
Staff of Sheldon-Hart Mountain National Wildlife Refuge Complex, Cattoor Livestock Roundup, M. O'Sullivan, L. Pielstick, M. Lund, L. Karwal, C. Carney, S. Goal, M. Samuel, T. Rocke, P. Steblein
USGS Biocomplexity Thesaurus
Mammals
U. S. Government
Unknown
Integrated Taxonomic Information System (ITIS)
ONLINE_REFERENCE
Unknown
http://www.itis.gov/
J. Christian Franson
U. S. Geological Survey, National Wildlife Health Center
mailing and physical
6006 Schroeder Rd
Madison
WI
53711
USA
608-270-2444
jfranson@usgs.gov
A single easily identifiable species was studied.
Identification was performed by professional biologists in the field setting.
non-domestic (i.e., wild or feral) horses (Equus caballus)
Kingdom
Animalia
Subkingdom
Bilateria
Infrakingdom
Deuterostomia
Phylum
Chordata
Subphylum
Vertebrata
Infraphylum
Gnathostomata
Superclass
Tetrapoda
Class
Mammalia
Subclass
Theria
Infraclass
Eutheria
Order
Perissodactyla
Family
Equidae
Genus
Equus
Subgenus
Equus (Equus)
Species
Equus caballus
feral horse
Horse
No formal attribute accuracy tests were conducted
No formal logical accuracy tests were conducted
Data set is considered complete for the information presented, as described in the abstract. Users are advised to read the rest of the metadata record carefully for additional details.
No formal positional accuracy tests were conducted
No formal positional accuracy tests were conducted
Data were collected in the field by professional biologists during 2004-2006, 2008-2009 and serologic testing was performed at the National Wildlife Health Center, U. S. Geological Survey.
2004
both
Sheldon National Wildlife Refuge (Refuge), managed by the U.S. Fish and Wildlife Service, consists of approximately 575,000 acres in northwest Nevada. The authors obtained portions of 1,397 serum samples from horses gathered on the Refuge, originally collected to test for equine infectious anemia, for flavivirus screening. These samples represented 15-40% of the minimum population on the Refuge each year, during 2004-2006 and 2008-2009. Horses were captured primarily by using a helicopter to herd them into a trap corral. Age of captured horses was determined by teeth characteristics and sex was determined (McMullan 1983).
Serum samples were heat-inactivated for 30 minutes at 56 degrees C and screened for flavivirus-specific IgM by using a WNV IgM capture enzyme-linked immunosorbent assay (MACELISA) and for flavivirus-specific IgG by using an indirect IgG ELISA (Johnson et al. 2000, Bunning et al. 2002). The assays were modified slightly by the use of recombinant WNV envelope antigen (Henessey Research Associates, Shawnee, KS) diluted 1:100 in phosphate-buffered saline-Tween 20 and the corresponding negative antigen (Henessey Research Associates). The peroxidase substrate system (2,2-azino-di (3-ethylbenzthiazoline-6-sulfonate); Kirkegaard and Perry Laboratories, Gaithersburg, MD) was used as substrate for the anti-flavivirus conjugate diluted 1:6,000 in blocking buffer for the MAC-ELISA and for the horseradish peroxidase-conjugated goat anti-horse IgG diluted 1:1,500 in phosphate-buffered saline-Tween 20 for the IgG ELISA. Reagent concentrations were determined by checker-board titration. If the optical density of a test sample divided by the optical density of the negative control was greater than or equal to 2.0, the sample was considered provisionally positive for IgM or IgG against WNV. Positive and negative control equine serum samples were used on each ELISA plate.
Serum samples determined to be provisionally positive for IgM or IgG against flavivirus were tested by using a two-fold dilution series and a plaque reduction neutralization test (PRNT) for reactivity to WNV (National Wildlife Health Center American crow [Corvus brachyrhynchos] isolate 16399-3) and St. Louis encephalitis virus (SLEV) (CDC TBH-28) (Beaty et al. 1989) Positive and negative control equine (WNV) or avian (SLEV) serum samples, a negative tissue culture control (no virus), and a positive virus control (virus test dose), were included in each PRNT. Sera that exhibited a 90% inhibition of the test dose of the virus were considered positive for the corresponding virus (PRNT 90). To differentiate between reactivity to WNV or SLEV, a four-fold difference in titer was required.
Horses sampled in 2008 and 2009 were assigned to four age groups (less than 1 year, 1-4 years, 5-9 years, and greater than or equal to 10 years). Horses sampled in 2004-2006 were excluded from statistical analysis because only one animal was seropositive for WNV during that time. The authors used logistic regression to determine if age or year affected the frequency of seropositive samples and tested for an age effect on seroprevalence within years by using chi-square analysis. The authors then performed pairwise comparisons of seroprevalence between age groups in 2008 and 2009 by using chi-square analysis with the Bonferroni correction.
McMullan WC, 1983. Dental criteria for estimating age in the horse . Equine Pract 5: 36-43.
Bunning ML, Bowen RA, Cropp CB, Sullivan KG, Davis BS, Komar N, Godsey MS, Baker D, Hettler DL, Holmes DA, Biggerstaff BJ, Mitchell CJ, 2002. Experimental infection of horses with West Nile virus. Emerg Infect Dis 8: 380-386.
Johnson AJ, Martin DA, Karabatsos N, Roehrig JT, 2000. Detection of anti-arboviral immunoglobin G by using a monoclonal antibody-based capture enzyme-linked immunosorbent assay. J Clin Microbiol 38: 1827-1831.
Beaty BJ, Calisher CH, Shope RE, 1989. Arboviruses. Schmidt NJ, Emmons RW, eds. Diagnostic Procedures for Viral, Rickettsial and Chlamydial Infections. Sixth edition. Washington, DC:American Public Health Association, 797-855.
Geographic Names Index System (GNIS) placename
Sheldon National Wildlife Refuge, Nevada, USA: GNIS ID # 864194
This dataset consists of one data sheet and associated data dictionary provided in both Microsoft Excel (.xlsx) and comma separated value (.csv) formats. Guidance on interpretation and use of the data dictionary is provided with the data in a text file.
http://dx.doi.org/10.5066/F7S75DDD
U.S. Geological Survey - ScienceBase
mailing and physical
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80225
USA
1-888-275-8747
sciencebase@usgs.gov
Unless otherwise stated, all data, metadata and related materials are considered to satisfy the quality standards relative to the purpose for which the data were collected. Although these data and associated metadata have been reviewed for accuracy and completeness and approved for release by the U.S. Geological Survey (USGS), no warranty expressed or implied is made regarding the display or utility of the data on any other system or for general or scientific purposes, nor shall the act of distribution constitute any such warranty. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government.
20201016
Kathy Wesenberg
U. S. Geological Survey
Information Resource Manager
mailing and physical
6006 Schroeder Rd
Madison
WI
53711
USA
608-270-2421
kwesenberg@usgs.gov
FGDC Biological Data Profile of the Content Standard for Digital Geospatial Metadata
FGDC-STD-001.1-1999