Fears further escalated that the new avian influenza A H7N9 may indeed be transmitted through human contact after the World Health Organisation (WHO) declared that some of those currently infected in China did not have had any contact at all with poultry.

This, as the seven-year old girl from Beijing who got infected with the virus had recovered from the sickness, was discharged and finally sent home on Wednesday.

The mystery virus, in just two weeks' time, has killed 16 lives and infected 82. The numbers are expected to escalate.

To date, both Chinese and international disease experts still cannot pinpoint the exact cause and origin of the new avian influenza A H7N9.

"It might be because of dust at the wet markets, it could be another animal source beside poultry, it could also be human-to-human transmission," Gregory Hartl, a spokesman from WHO, told Reuters. "This is one of the puzzles still (to) be solved and therefore argues for a wide investigation net."

Although there have been 11 H7N9 outbreaks identified in birds around China, the virus doesn't make birds sick.

"Something like 47,000 to 48,000 birds have been tested, and only 39 have come back positive," Mr Hartl said. "Those come from poultry, duck and pigeons."

On Tuesday, China's National Health and Family Planning Commission revealed 40 per cent of those infected had no contact with poultry.

The unidentified seven-year-old girl, together with her parents, addressed local reporters at a press conference organised by hospital authorities, that she "feels much better and wants to go home."

"I want to return home and play," she said.

Wearing a face mask, hospital authorities said the girl recovered through a combined treatment of Western and Chinese medicine.

Read more:

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China Bird Flu Pandemic: UN's FAO Alarmed H7N9 Virus Could Spread Outside China