In its April 13 Situation Report, the United States Department of Agriculture (USDA) Animal and Plant Health Inspection Service (APHIS) confirmed the year’s first cases of vesicular stomatitis virus (VSV) in the United States. Horses on two premises tested positive for VSV (Indiana serotype) — a single horse on a Dona Ana County premises, which met the case definition of infection with compatible clinical signs and virus isolation-positive results, and another premises in adjoining Sierra County — which met the case definition with compatible clinical signs and reverse transcription-polymerase chain reaction (RT-PCR)-positive results.

The Dona Ana County horse, which is the only horse on its premises, presented with coronary band lesions around April 6. No other animals, including livestock, reside on the premises, and no livestock have moved on or off the premises.

At the Sierra County premises, only one of the three horses in residence showed coronary band lesions, around April 8. No other susceptible species reside on the premises, and no livestock have moved on or off the premises. Both premises are under state quarantine.

VSV-Indiana serotype was last isolated in the United States during the 2019 VSV outbreak