Over 100 people in south China's Guangxi Zhuang Autonomous Region who had been in contact with a girl diagnosed with H5N1 avian influenza have been released from medical observation, the local health department reported on Wednesday.

Tan Mingjie, deputy head of the regional health bureau, told Xinhua News Agency that a series of measures have been taken to prevent further human infections.

The 10-year-old girl named Tang, from Baiyangping Village of Liangshui Township in Ziyuan County, fell ill with fever and pneumonia on November 23.

The health ministry confirmed on Tuesday that she had been diagnosed by the Chinese Center for Disease Control and Prevention (China CDC). She is now undergoing close treatment and is making a quick recovery.

WHO spokesperson Roy Wadia told China Daily that she had reportedly had contact with domestic poultry one to two weeks before she fell ill, but that the details were sketchy.

Wadia said the WHO does not know where the poultry was, whether any birds were ill, or exactly how she contracted the virus.

Local experts, as well as those sent by the Ministry of Health, are investigating potential sources of exposure.

There have been no reports of bird flu outbreaks amongst poultry in Guangxi this year, though the region was the first to report infections last year on January 27, 2004.

But Ziyuan County does neighbor Hunan Province, which has reported both human cases and bird outbreaks this year.

Wadia said it is difficult to trace isolated outbreaks on small farms and stressed that there was no evidence that the virus had acquired the ability to jump effectively or efficiently from human to human.

Also yesterday, Hubei Province's headquarters for the prevention and control of highly pathogenic bird flu said the quarantine of Xiaonan District of Xiaogan City, where an outbreak was confirmed by Ministry of Agriculture on November 17, has been lifted, according to Xinhua.

China has reported 30 outbreaks amongst birds this year in 11 provinces and autonomous regions and reported four confirmed human infections, as well as one likely but unverifiable one.

(Xinhua News Agency, China Daily December 8, 2005)