The Hong Kong family whose teenage son slipped into a vegetative state last week after receiving treatment at a hospital in Shenzhen lashed out yesterday at medical staff for trying to deny responsibility for the incident. Tsang Chun-wah, a 17-year-old student who lived with his parents and sister in Tuen Mun, was admitted to the Sha Jing People's Hospital in the Baoan district of Shenzhen last Tuesday after he felt uncomfortable and vomited during a family trip across the border. The teenager's condition seemed to improve after two days of treatment, but it deteriorated suddenly on Thursday when he was placed on a drip. A relative recalled that after the drip had been administered, the teenager's face began turning black, while big patches of red spots appeared all over his body. The teenager began having difficulty breathing and his heartbeat stopped, a spokesman for the hospital said yesterday. The next morning, the hospital decided to conduct a skull-dissection operation on the patient, who suffered severe hydrocephalus in which abnormal accumulation of cerebrospinal fluid had accumulated in the brain. After surgery, the hospital said the teenager's brain stem was dead and that he was in a vegetative state. His parents, who were by their son's side during all his treatment at the hospital, were overwhelmed by the outcome. 'It is mental breakdown for our whole family,' said father Tsang Shu-hing yesterday, who was crying next to his son's bed. The teenager now relies on a machine to breathe for him. 'How can we believe our healthy son has turned into a vegetable overnight?' he asked. The family suspected the medicine in the drip that the doctor used on the boy caused a severe allergic reaction. They also accused the hospital of conducting the surgery in a ward where equipment was not sufficiently disinfected, rather than in an operating theatre. The hospital ruled out the possibility of an allergic reaction, insisting staff had done skin tests before placing the teenager on the drip. 'It is common for us to do operations in a ward, which is aimed at saving as much time as possible to treat critical patients,' the hospital's spokesman said. The hospital revealed yesterday that the teenager probably suffered myocarditis - an infection or inflammation of the myocardium, the muscular part of the heart - but an exact determination would not be available without an autopsy. Mr Tsang said he had called mainland government departments and health authorities, including the liaison office of the central government in Hong Kong and the Baoan District Health Bureau. No one offered help. The Immigration Department in Hong Kong said it could help the family transport their son home.