The woman who returned to Perth from West Africa has been admitted to the Sir Charles Gairdner Hospital with Ebola-like symptoms, watoday.com reported Tuesday.
The woman was showing Ebola-like symptoms but could be suffering from malaria.
"The woman under investigation has some symptoms that are often associated with Ebola, but does not fit the picture of Ebola virus infection," a health department spokesman said.
"While tests are being undertaken to determine the cause of illness, it is appropriate to take a precautionary approach, whereby the patient is isolated and measures are taken to minimise the risk of transmission of any infectious agent," the spokesman said.
Earlier, a 25-year-old man and an infant sparked an Ebola virus disease scare in Queensland and Victoria respectively. Both of them were tested negative for the disease.
The deadliest Ebola virus disease epidemic in history has claimed 2,800 lives in west Africa, the World Health Organisation (WHO) said Monday.
A total of 5,800 people were infected with the Ebola virus in the hardest-hit countries -- Guinea, Liberia and Sierra Leone, the UN health agency said.