FUZHOU -- It has been confirmed that a five-year-old girl contracted HIV due to a blood transfusion during an operation four years ago, said the health authority in Fujian province, southeast China.

The provincial health and family planning committee said the Fujian Medical University Union Hospital, where the operation took place, and the blood center, which supplied the blood, must give "humanitarian compensation" to the child, Maomao (not her real name), and her family.

Maomao was just eight-months-old when she underwent heart surgery for congenital heart disease in May 2010.

She tested positive for the virus during a physical examination in September 2014.

Her parents said Maomao was a sickly child and prone to illness. But her condition worsened in August 2014, when she came down with a high fever that lasted 17 days. She was then found to be HIV positive.

Maomao's medical fees have spiralled to 300,000 yuan ($48,320) and her family are now in debt.

Her parents believed the operation was to blame for their daughter's dire health and they demanded a thorough investigation.

"One of eight blood donors, whose blood was used during Maomao's operation, is a person living with HIV/AIDS (PLWHA), who had no idea that he/she was a PLWHA when he/she donated blood, and the blood was accepted as he/she was in a 'window period'," said Yang Minhong, an official with the committee.

A "window period" is the two to four week window from infection before a test can detect the presence of the virus.

The investigation into Maomao's case found that neither the hospital nor the blood center had broken any law or regulation on blood collection and transfusion, said Yang.

"It's a shame that with in this day and ages, a PLWHA cannot be identified during such a specific period of time. Maomao's case is a rare event that sadly occurred even with modern blood testing technology," said Yang.

The hospital and the blood center will start negotiations with Maomao's parents regarding the compensation.

"If it does not work out. Maomao's family can file a law suit," said Yang.

To make things worse, the donor's blood was also transfused into two other patients. The committee is trying to locate the two patients, said the official.

The blood donor made the one-off donation on March 31, 2010.

Following Maomao's case, the Fujian provincial health authorities are also working on a compensation mechanism for this type of "no-fault" blood transfusion case.