A 31-year-old Chinese woman farmer has been diagnosed with the deadly H5N1 bird flu virus, the ministry of health said Thursday night.
This case, from the north-eastern Liaoning province, is China's fifth confirmed case of bird flu in the last two months.
She tested negative for laboratory tests before December 5 but on that day, experts from the Chinese Centre for Disease Control and Prevention tested her blood samples again and she tested positive for the deadly H5N1 strain of the virus.
All the people who had close contact with her are free from the disease.
Of the other four who tested positive for H5N1, two were reported in East China's Anhui Province, and one each in Central China's Hunan Province and South China's Guangxi Zhuang Autonomous Region.
Two female farmers from Anhui province died from the deadly strain in November. A girl in the Guangxi region has undergone emergency treatment.
The H5N1 virus has killed nearly 70 people in South East Asia since its outbreak in 2003.
The latest victim of bird flu in China fell ill in Heishan county on 30 October, according to Xinhua news agency. She had a high fever and pneumonia-like symptoms, but she recovered following treatment at a hospital and was discharged on 29 November, it said.
The China Daily newspaper has said there have been at least 30 avian outbreaks of bird flu in 11 provinces and regions this year.
The Chinese authorities have culled millions of birds, but experts are warning that the virus is entrenched in parts of the country.
Beijing intends to vaccinate all of the country's estimated 14 billion poultry, but it is feared that wild birds could spread the virus.
The disease does not transmit easily from birds to humans, and no human-to-human cases have been confirmed.
But health officials remain fearful that the virus could mutate into a form that could spread from person to person, potentially sparking a global pandemic.
Meanwhile, the State Forestry Bureau yesterday set up a State-level surveillance station for wild-life epidemics in Shenyang, capital of Liaoning Province.
The station will monitor various infectious diseases and their sources among wild animals, especially migratory birds, Zhao Liangping, director of the station, said yesterday.
Migratory birds have been confirmed by scientists as one of the carriers of the avian influenza virus.