Most horses have been infected with EHV-1, but the virus can become latent and persist without ever causing signs of infection. In 2006, an outbreak of EHV-1 among stables in Florida resulted in the institution of quarantine measures.
Many horses are carriers of EHV-1, yet the virus can remain latent and not manifest symptoms indefinitely. In 2006, a widespread EHV-1 outbreak at stables in Florida necessitated the introduction of quarantine protocols.