An 18-year-old woman is relieved she has tested negative for Ebola after arriving in Queensland from west Africa, but understands she needs to have more tests, officials say.

Queensland’s chief health officer Dr Jeannette Young says a total of 19 people are in home isolation in relation to Ebola.

But the 18-year-old, members of her immediate family, and others confined to their homes after recently arriving from west Africa appear to be well,  Young has told reporters in Brisbane.

Young said four families, including the girl’s family, had arrived in Brisbane under humanitarian circumstances.

The families came separately and officials knew in advance they were headed to Queensland, she said.

Because they were coming from Ebola-hit parts of west Africa, they were asked if they would voluntarily enter home detention on arrival, which they did.

Young said none of the 19, other than the girl, who remains in isolation in hospital, had shown any symptoms of the virus.

The 18-year-old girl will undergo a second test for Ebola on Wednesday, she said.

A clinician is phoning the isolated families each day to discuss any changes in their condition and ensure any potential infection is detected early.

“If they have any symptoms at all we get notified and then the plan is the person is transported to the relevant hospital by ambulance,” Young said.

She said she didn’t have specific details at this stage of any other families from west Africa who were planning to come to Queensland.

The 18-year-old is the third person in Queensland to have been tested for Ebola.

A Gold Coast man, 27, was cleared in mid-September after claiming to have spent time in Africa and having vague symptoms.

Cairns nurse Sue-Ellen Kovack, 57, who developed a fever after returning from treating Ebola patients in Sierra Leone, tested negative on October 10.

She’s since been released from home isolation.

Young again urged members of the public not to panic, saying the virus is hard to contract.

“It isn’t contagious like measles or a cold or the flu … you need direct contact with excretions from someone who is sick at that time.”

She said about 18,000 people travelling from west Africa had already been checked before boarding planes there.

Anyone travelling to Australia would have their temperatures checked at their arrival point as well, she said.

Two health care workers from Queensland are still in west Africa and will go into home quarantine when they return, Young said.