Table 2.
Unvaccinated and Locally-Bred Horses Positive for Antibodies to WNV, SLEV, ILHV, and FLAV
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HIA titer |
Epitope b-ELISA (%I)a |
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| Sample ID | Locality by town | Gender | Age group (y) | WNV | SLEV | ILHV | FLAV | WNV | SLEV | WNV capture IgMb | WNV PRNT titerc | SLEV PRNT titerd |
| 1C11H | Chaguanas | F | 1–5 | 1:40 | 0 | 0 | 55.2 | 21.4 | 4.1 | 1.0 | 160 | <20 |
| 1CH3H | Chaguaramas | M | >10 | 0 | 0 | 0 | 39.0 | 36.4 | 1.6 | NT | NT | NT |
| 1O7H | Wallerfield | F | 6–10 | 1:320 | 1:20 | 0 | 87.7 | 0 | 26.3 | 1.4 | 320 | <20 |
| 1OR2H | Wallerfield | F | Unknown | 1:320 | 1:20 | 0 | 90.3 | 83 | 19.7 | 1.1 | >640 | <20 |
| 1P1H | Petit Valley | F | 1–5 | 1:320 | 1:40 | 1:20 | 62.1 | 47.9 | 10.6 | 2.6 | NT | NT |
| 1P3H | Petit Valley | F | 6–10 | 1:320 | 1:40 | 1:40 | 73.7 | 43.2 | 29.5 | 1.2 | NT | NT |
| 1S3H | Santa Cruz | M | 1–5 | 1:2560 | 1:160 | 1:160 | 94.9 | 80.7 | 23.3 | 16.3 | >640 | 160 |
| 1S4H | Santa Cruz | M | 1–5 | 1:2560 | 1:80 | 1:40 | 93.5 | 86.9 | 23.3 | 2.7 | >640 | 40 |
| 1S5H | Santa Cruz | M | 1–5 | 1:1280 | 1:160 | 1:80 | 81.3 | 75.2 | 2.7 | 3.0 | >640 | 40 |
| 3RT5H | Arima | F | 1–5 | 1:40 | 0 | 0 | 43.7 | 0 | 29.4 | 1.1 | 160 | <20 |
| 3RT19H | Arima | F | 1–5 | 1:160 | 1:20 | 0 | 41.4 | 0 | 21.5 | 1.3 | 320 | 20 |
Interpretation for epitope-blocking ELISA: <30% inhibition (%I) is antibody-negative, and >30% inhibition is antibody-positive.
West Nile immunoglobulin type M capture ELISA interpretation: <2.0 is antibody-negative, 2.0–3.0 is equivocal, and >3.0 is antibody-positive.
Plaque reduction neutralization test (PRNT) for WNV (titers are expressed as the reciprocal of the serum dilution yielding 90% reduction in the number of plaques).
PRNT for SLEV (titers are expressed as the reciprocal of the serum dilution yielding 90% reduction in the number of plaques).
ELISA, enzyme-linked immunosorbent assay; HIA, hemagglutination inhibition assay; SLEV, St. Louis encephalitis virus; EEEV, eastern equine encephalitis virus; VEEV, Venezuelan equine encephalitis virus; WNV, West Nile virus; ILHV, Ilheus virus; NT, not tested.