The National Veterinary Services Laboratories (NVSL) in Ames, Iowa, confirmed a finding of vesicular stomatitis virus (VSV) infection (Indiana serotype) on an equine premises in Platte County, Wyoming, on July 24, 2019. Horses on the premises have met the case definition of infection with compatible clinical signs and positive test results for the virus. This is the 2019 index case of VSV for Wyoming.
Additionally, U.S. Department of Agriculture/Animal and Plant Health Inspection Service provided state-by-state VSV updates since its last situation report on July 18, 2019.
The state has had 40 new confirmed positive cases and 38 new suspect premises, including:
- Adams County – one new confirmed positive premises;
- Archuleta County (newly infected county) – two confirmed positive, one suspect premises;
- Boulder County – eight new confirmed positive cases, three newly suspect premises;
- Broomfield County – one new suspect premises;
- Delta County (newly infected county) – one confirmed positive premises;
- La Plata County – five new confirmed positive cases, six new suspect premises;
- Larimer County – 14 new confirmed positive cases, 25 new suspect premises;
- Montezuma County (newly Infected County) – one confirmed positive premises;
- Morgan County (newly infected county) – one confirmed positive premises; and
- Weld County – seven new confirmed positive, two new suspect premises.
The following previously VSV-infected or suspect premises have been released from quarantine:
- One in Larimer County, and
- Two in Weld County.
The state has one new confirmed positive cases and six new suspect premises:
- Rio Arriba County – one new suspect premises;
- Santa Fe County – two new suspect premises; and
- Valencia County – one new confirmed positive cases and three new suspect premises.
The following previously VSV-infected premises have been released from quarantine:
- One in Los Alamos County and three in Sandoval County.
The state has two new confirmed positive and 11 new suspect premises, including:
- Bastrop County – two new confirmed positive, 10 new suspect premises;
- Hays County – one new suspect premises;
- Hood County – one new confirmed positive premises; and
- Somervell County (newly infected county) – one confirmed positive premises.
Classification of Cases
States categorize premises as confirmed positive after receiving laboratory diagnostic confirmation of VSV. Once a county is confirmed VSV-positive, new equine premises presenting with clinical signs of VSV in that county do not have to be tested for confirmation of the disease. The premises will immediately be quarantined and classified as a suspect premises.
Confirmed positive and suspect premises are quarantined for at least 14 days from the onset of lesions in the last affected animal on the property.
The 2019 VSV outbreak began on June 21, 2019, when the NVSL confirmed the first VSV-positive premises in Kinney County, Texas. New Mexico, Colorado, and Wyoming subsequently broke with cases, which NVSL confirmed on June 26, 2019 (Sandoval County, New Mexico), July 3, 2019 (Weld County, Colorado), and July 24, 2019 (Platte County, Wyoming).
To date, all confirmed cases have been found on equine premises in these four states. Since the start of the outbreak, 209 VSV-affected premises have been identified (124 confirmed positive, 85 suspect).
Colorado has identified 134 affected premises (71 confirmed positive, 63 suspect) in 10 counties (Adams, Archuleta, Boulder, Broomfield, Delta, La Plata, Larimer, Montezuma, Morgan, and Weld).
New Mexico has identified 37 affected premises (28 confirmed positive, nine suspect) in six counties (Los Alamos, Rio Arriba, Sandoval, Santa Fe, Taos, and Valencia). Texas has identified 37 affected premises (24 confirmed positive, 13 suspect) located in 13 counties (Bastrop, Coleman, Hays, Hood, Johnson, Kerr, Kinney, Shackelford, Somervell, Taylor, Tom Green, Val Verde, and Wichita).
Wyoming has identified one affected premises in one county (Platte).
A total of 14 previously VSV-infected or suspect premises have completed the quarantine period and been released.