Yes, they came over on the same plane so they were all quarantined together and intentionally the last allowed on the grounds and the first to leave. They had to be escorted for any activity outside of the stabling area by a vet or vet-tech and were not allowed out into the common areas. As CEM is a STD there really wasn't much risk, but that was how the USDF & USEF wanted to handle it. They all had to be off of the property immediately after the ride, thus the reason they didn't stand for BC.
Living in the area, Kentucky and especially the Horse Park take any risk very seriously. I've actually been pulled over and inspected just driving through the state.
They were subject to all drug testing at the finish as well, I escorted one of them down for testing.
