The volunteer nurse who is being monitored inside a Queensland hospital for Ebola has tested negative, a Queensland Health official has confirmed.

Sue Ellen Kovack was tested for the deadly virus on her return from Sierra Leone where she was volunteering with the Red Cross in the fight against Ebola.

There were fears the 57-year-old, from Cairns, was suffering from the illness she was helping to treat after she reported feeling a fever at 1pm AEST on Thursday.

Ms Kovack was put under observation and quarantined at Cairns Hospital.

Chief Health Officer Dr Jeannette Young stated on Friday morning that initial tests taken have returned a negative result.

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Sue Ellen Kovack volunteered as a nurse treating Ebola patients in Sierra Leone last month

Ms Kovack posted a number of snaps of her on the job in Sierra Leone on her Facebook page

There are an estimated 7,200 Ebola cases in West Africa, according to the latest figures from the Centre for Disease Control

Dr Young said the woman was likely to remain under observation for at least another 24-hours.

'This is a necessary precaution given the patient has been to West Africa and has had a fever within the incubation period of 21 days. For the sake of her health and to follow due diligence, we want to be sure she is clear of Ebola virus disease as well as any other disease.'

Dr Young said regardless of the outcome of the tests, the broader community was not at risk of contracting EVD.

Ms Kovack just returned to Australia on Tuesday after a month volunteering for the Red Cross in the West African nation.

Red Cross Australia confirmed one of their aid workers was under observation for the deadly virus.

'Our heartfelt thoughts are with the Red Cross aid worker and her family. We will do everything we can to support her at this difficult time,' the organisation's head of international program Peter Walton said in a statement to the Red Cross Australia Twitter page.

Mr Walton later told 9News: '[Ms Kovack's] well, I've spoken with her recently.

'We just have to play a bit of a waiting game.

'She's in good spirits - she's feeling good at the moment.'

Ms Kovack decked out in medical gear during her stint in the West African nation

Dr Jeannette Young broke the news at a press conference on Thursday afternoon

A friend of Ms Kovack's, Jennifer King, told ABC's Lateline the volunteer nurse was 'popular' and 'well-known' in the Cairns medical community, and her situation had sparked an outpouring of support from her colleagues at the north Queensland hospital.

Ms King said her friend of 25 years was used to working in the tough conditions of African nations.

'She wants to help people, she's incredibly compassionate and she's selfless like not many people on earth,' Ms King said.

'A bunch of the nurses [at Cairns Hospital] have gone down to Accident and Emergency [department] to offer to nurse Sue Ellen, which is really brave.

SPREADING WITH DEADLY SPEED: EBOLA VIRUS Ebola virus disease (EVD) - which is thought to have originated in fruit bats - is often fatal to humans

The deadly disease is passed from animals to humans and can be spread from person to person

There are five types of Ebola including Zaire, Bundibugyo, Sudan, Reston and Taï Forest

Guinea, Sierra Leone and Liberia are currently the most infected countries but it has spread to Nigeria and Senegal, according to the ABC

The World Health Organisation says the latest strain in west Africa is of the Zaire species

Symptoms of the disease include fever, fatigue, muscle pain, headache and sore throat at the start

Then vomiting, diarrhoea, rash, kidney and liver dysfunctions and sometimes there is internal and external bleeding, such as from the gums and in stools Advertisement

'They're upset and they want to help.'

But Ms Kovack's humanitarian efforts have been slammed by outspoken Federal MP Bob Katter.

The member for Kennedy - whose electorate takes in the southern area of Cairns and the town's airport - said her volunteering pursuits had put the nation at risk.

Mr Katter said it was 'unbelievable and incomprehensive' how a person could get into Australia from an Ebola-infected country.

'There cannot be any compromise with this,' Mr Katter said.

'If you want to go to one of these countries, however laudable your motivation, I am sorry but when you return to Australia, you must be quarantined for three weeks - not home quarantined.'

Mr Katter said Australian aid workers travelling to west Africa, including Ms Kovack, were putting Australia at risk.

'We love these people, and we honour these Australians for being self-sacrificing, but compared to the risk they create for our country, it is not remotely comparable. One person's moral and humanitarian ambitions are being carried out at a very grave cost to Australia,' he said.

But Queensland's chief medical officer Dr Jeannette Young praised Ms Kovack's efforts and said she had acted appropriately when raising the alarm to health authorities.

'I think she's an amazing lady to go to Africa and provide that service,' Dr Young said.

She added: 'She has done everything appropriately.'

Ms Kovack has been in isolation since she returned home as is the protocol for medical workers who have treated Ebola patients overseas.

Dr Young said Ms Kovack had been testing herself in the 'isolation' of her own home and had not been into the Cairns community since she returned on Tuesday.

'This morning she rang up as part of [national health] protocol because she developed a low-grade fever of 37.6 degrees Celsius.

'But we felt it important that she come into Cairns Hospital for Ebola virus disease.'

Ms Kovack is originally from Toronto, Canada but is living in Cairns, Queensland

Cairns Hospital where the 57-year-old is under observation and quarantined

Dr Young stressed it was almost impossible that Ms Kovack to have infected other people, including her housemate who is showing no symptoms or passengers on her flight, as she did not develop symptoms until Thursday morning.

Doctors awaited the results of a blood test and received the results early Friday morning as the sample had been sent to Brisbane for testing on Thursday afternoon.

Dr Young said the actual blood testing process took about four hours.

A Federal Department of Health spokeswoman told Daily Mail Australia any health care worker who comes back from an affected country needs to monitor their health - including taking their temperature twice a day - and cannot return to work for 21 days.

Health Minister Peter Dutton has moved to reassure the public that talking to people arriving from Ebola-hit countries is still the best method of screening for the deadly disease.

He said doctors still backed the process to identify and contact people arriving into the country who may have been exposed to the disease.

'I think that's the more effective screening process at the moment, but these things evolve,' he told the ABC.

Mr Dutton said introducing a screening in arrivals halls could be problematic.

'It provides a sort of air of complacency if you like,' he told the ABC.

'So people come through, they feel unwell a couple of days later and they think "No, no, I've just been through that screening process and I wasn't picked up, I'm ok".'

Mr Dutton reiterated the World Health Organisation had not asked Australia for on-the-ground health workers in the stricken African countries.

But he said that advice may change over time.

Australia will send help if a case presents in the region, for example in PNG, the minister says.

'We would be expected within our region to rapidly respond, and we have the capacity to do that with a team out of Darwin ... and resources within Canberra,' Mr Dutton said.

Before she left for Sierra Leone, Ms Kovack spoke to media about her journey, and was actively keeping her friends and family up to date on Facebook.

'I'm a little bit nervous, a little bit anxious but healthily anxious I think,' she told local newspaper The Cairns Post.

In an interview with the ABC last month, she said it was her responsibility to help those in need.

'I care about humanity and if I have what people need, I would like to use these skills.

'Why me? Well, if not me then who?' Ms Kovack said.

Except for the fever, Dr Young said Ms Kovack was 'perfectly well' but because of the circumstances: 'I am treating it as if it was (Ebola)'.

She said there was no risk to fellow passengers on Ms Kovack's flights home.

'She did not have any symptoms at all when she was on those flights, so there is no risk at all,' she said.

'The Ebola virus is very difficult to transmit.

'It's not transmitted through the air - you need to be exposed to secretions: vomit, diarrhoea, blood.

'She doesn't have any symptoms producing those secretions.'

Ms Kovack is expected to find out on Friday morning whether or not she has the deadly virus

Ms Kovack recently shared happy snaps of her in Sierra Leone, dressed in quarantine uniforms and being sprayed by decontamination hoses.

On September 23, she wrote: 'Big day... Have taken our first bloods from our first ebola survivor at the (International Federation of the Red Cross) treatment centre.

It was not the first time Ms Kovack had travelled overseas to help those in need.

She had previously worked with the Red Cross in war-torn South Sudan and had volunteered in Sierra Leone in 2002.

The Ebola virus has infected an estimated 7,200 people, according to the World Health Organisation. More than 3300 have died.

There have been no recorded cases in Australia.

Last month, a Gold Coast man was placed in isolation after he was feared to be suffering the deadly illness.