The hospital and blood center do not bear any liability for a five-year-old girl's infection of HIV during an operation in Fuzhou, Fujian province four years ago, according to the provincial health authority.

Maomao (nickname) was found to carry the deadly HIV virus in a physical checkup in September, 2014. Further investigation confirmed that she contracted HIV from a blood transfusion during an operation for her congenital heart disease in 2010.

The HIV blood was from one donor who passed routine tests during the blood donation because he was in a window period, which refers to a two to four-week period after infection during which a test cannot detect the virus.

The rate of HIV infection during a window period is about 1/500,000, said Yang Minhong, an official with the provincial health and family planning committee.

Under Chinese law, blood centers and medical institutions cannot be blamed for HIV infection by a blood donor during the window period, she added.

The Committee also said it will provide humanitarian compensation and assistance for the girl.

"The (infection during) window period is inevitable, while the blood transfusion is a must. We can only call on donors to keep a healthy life and give safer blood," said Lai Dongsheng, an official with the blood center.