The eight considered to have exposure to a horse that died from the disease this week will undergo blood tests at fortnightly intervals for six weeks to monitor for infection.
They have been told what symptoms to watch for.
Hendra, carried by native fruit bats in Australia, can infect horses. From horses, the virus is able to make the jump into humans.
Of the seven known cases of Hendra infection in people since 1994, four have proved fatal. The last two victims were equine veterinarians.
Testing confirmed the case of Hendra at Kerry, near Beaudesert, this week.
The horse had been at an agistment facility and had been brought home when unwell.
The two properties involved are now under quarantine, and five other horses are undergoing tests at the agistment property for the virus, but are not showing signs of the disease.
Queensland Health said none of the eight people considered exposed had shown indications of infection.
Biosecurity Queensland Chief Veterinary officer Rick Symons said blood samples had already been taken from five horses, on Wednesday.
"All of these horses appeared clinically normal on examination by Biosecurity Queensland vets but we need to wait for results later this week to find out whether the horses are negative on this first round of testing.
"Further rounds of testing will then need to be conducted before the quarantine can be lifted.
"About 25 horses on the second property where the horse was transported, and later died, will also be examined and samples from these animals will be tested.
"It is understood the sick horse was isolated from these horses when it was moved to the property. However, the risk of exposure of individual horses on the property is still being assessed.
"Full tracing is also being undertaken to locate any other horses that may have been in contact with the infected horse.
"Both properties will remain under quarantine - this means that no movement of horses to or from these properties is permitted - until Biosecurity Queensland is sure there is no further risk of infection. This is typically 30 to 35 days."
Symons said the property where the infection occurred would also be surveyed for flying foxes.
"At this stage we have only conducted a visual inspection and have identified some large fig trees in the horse paddock that flying foxes could inhabit," Dr Symons said.
"Further investigations to identify recent flying fox activity in the area will be undertaken, including sampling of flying fox populations."
Dr Symons said Biosecurity and Queensland Health officers had been conducting a door knock of neighbours in the immediate vicinity of the properties to notify them of the incident and to provide information.
"A Department of Employment, Economic Development and Innovation mobile office has also been set up in Beaudesert for people who want to discuss their situation with Biosecurity Queensland or Queensland Health.
"Our industry liaison officer will continue to work with the affected property owners as well as the private veterinary practice involved. This officer is an experienced veterinarian and is providing expert advice and support to those involved, including advice on biosecurity practices."