Zhangjiajie health authority said, the boy was confirmed HIV positive in July 2015, after he received a blood transfusion in January, 2014 when he was seriously injured in a traffic accident.
The authority said that although the boy had definitely been infected, it was difficult to determine the exact source and route of the infection.
During a period of 18 months, he was hospitalised eight times in three different hospitals -- Zhangjiajie people's hospital, the provincial children's hospital in Changsha and a Shanghai hospital.
However, the boy also spent considerable time outside the hospitals, which makes ascertaining the precise source of the infection difficult.
In addition to the three hospitals, the co-defendants also include the Zhangjiajie city blood station and a Chinese biological company that produced the human serum albumin, which the boy received in a transfusion during his first operation, the report said.