A man, who contracted Hendra virus from horses at the Redland Bay veterinary clinic, was readmitted to hospital on Wednesday. And a woman was admitted to hospital Thursday night for observation.
The virus broke out last week where one horse died and another was put down.
Up to 50 people who had contact with the property have been screened for the virus.
Clinic owner Dr David Lovell says staff are devastated by the latest positive test.
"I guess no one really knows what to do, but we're all very close," he said.
Dr Lovell says the infected pair reported a range of symptoms.
"Bit of aches and pains, headache and certainly a fever," he said.
Queensland Health spokesman Doctor Brad McCall says the two are doing well but are still being closely monitored.
There is no vaccine for the virus but Dr McCall says he is confident they have the necessary skills to treat it.
"Two cases in question, the two people in question, are under the care of medical specialists," he said.
"We have leading specialists in this field, as you know Queensland has had the experience, the unfortunate experience and tragic experience with this case in the past so therefore we have probably very good local expertise on this."
Biosecurity Queensland says it will now ask federal and interstate experts to help review protocols on dealing with horses infected with Hendra virus.
Chief Veterinary Officer Ron Glanville says the latest human case highlights the urgent need for the review.
"It certainly is a bit of a wake up call for veterinarians dealing with horses," he said.
Dr Glanville says a local task force is nearing the end of its investigation.
"We hope to have some results out of that sometime next week," he said.
"One of the important things is the way the disease expressed itself in this Redlands case is different to what we've seen previously.
"We've already done a quick revision of the guildines for veterinarians in terms of what to look for, but after this event, we'll need to look at all those aspects - what sort of symptoms vets look for, how they treat, how they approach investigations of sick or dead horses - all that sort of thing."