MANILA - Health officials are investigating two patients in the Philippines and Australia showing symptoms of a new, mysterious coronavirus spreading from China's Wuhan province.

A five-year-old boy was taken to a hospital in Cebu City, in central Philippines, just hours after he arrived with his mother from Wuhan on Jan 12. He was coughing and had a fever.

A man in Brisbane, meanwhile, was in isolation in his home, as the Queensland health authorities ran tests on whether he was carrying the Wuhan virus.

The man recently returned from Wuhan, and would have flown into Sydney from China.

The authorities said there was no cause for alarm.

Queensland chief medical officer Jeannette Young said the man was recovering at home in the north-eastern city of Brisbane, where the health authorities were awaiting the results of tests to determine whether he had contracted the new virus.

Philippine Health Secretary Francisco Duque told reporters samples taken from the five-year-old boy tested negative for Sars or Mers, illnesses caused by two deadly coronavirus strains.

But the samples tested positive for a "non-specific pancorona virus", and were sent to a laboratory in Melbourne, Australia, for further tests.

The respiratory illness caused by the new coronavirus had also been detected in Beijing, Shanghai and Shenzhen.

The World Health Organisation (WHO) had tallied 222 cases so far, 218 of which were in China.

Four people have died.

Japan, Thailand and South Korea had reported a total of four cases.

Dr Duque said the boy from Wuhan was still coughing, "but is currently stable".

Test results from Australia should be known in two days, he said.

Three Chinese tourists heading for the popular resort island of Boracay on separate dates last week had also been tested for the new virus after they showed flu-like symptoms.

They were shown to have just mild cases of the flu, and allowed to proceed to Boracay.

"Signs and symptoms manifested by these three Chinese nationals… did not fit the case definition… of the new coronavirus… There was no reason to hold them. They were not persons under investigation," said Dr Duque.

The new strain of coronavirus can pass from person to person, China has confirmed.

Respiratory expert Zhong Nanshan, who heads the health commission team investigating the virus, said 14 medical workers had caught it while treating patients.

The outbreak has revived memories of the Sars virus that killed 774 people in the early 2000s across dozens of countries, mostly in Asia.

Analysis of the genetic code of the new virus shows it is more closely related to Sars than any other human coronavirus.

The BBC reported that the number of people infected could still be far greater, with estimates closer to 1,700.

Dr Rabindra Abeyasinghe, the WHO's representative in the Philippines, said "it's too early now to say that it is a severe infection".

"We are in the early stages of trying to understand how severe this infection is, and how many deaths it is likely to cause," he said.