A HIV-positive drug addict has told how he may have infected up to 10 fellow inmates at a drug rehabilitation centre by sharing needles. The disclosure came as health officials warned against the practice, with the number of HIV cases on the rise among addicts. Long-time heroin user Mo Wai-kit, 51, told the South China Morning Post he had shared needles with 10 other inmates at Shek Kwu Chau drug rehabilitation centre during repeated admissions in the early 1990s. He did not find out about his condition until 1994. 'I hope my story will be a lesson - needle sharing is very bad,' he said. 'Most drug addicts, including myself, have never thought about having the disease. We are aware of the risk, but we just ignore it, and there is no choice when you are locked up and have the urge.' He was sent to the Shek Kwu Chau centre, run by the Society for the Aid and Rehabilitation of Drug Abusers (Sarda), eight times after being convicted of various charges of shoplifting and theft. Mr Mo is now one of two HIV-positive addicts at the Christian Zheng Sheng Association's drug rehabilitation centre in Kam Tin, which requires HIV tests for all new inmates. He has taken heroin for more than three decades and shared needles as frequently as three times a day. 'Back in the 1980s, sharing needles was very common. At that time, only glass syringes were available and each cost about $4 or $5 - expensive to us. A bag of heroin only cost $10 in those days, so we usually used the old needle together. I did so for about 10 years, three times a day.' Mr Mo was not aware he was infected until he took a blood test after he was struck down by tetanus in 1994. His doctor said he had contracted the disease from sharing needles. 'The news shocked me. I did not believe it at all when the doctor told me I was infected,' he said. 'After I cooled down, I asked myself: 'I have such bad luck but what can I do? If I have a choice, I would have chosen to be kept in the dark. 'I got this disease from needle sharing, but at the same time, I am afraid that I also spread it to others. It is too late for regret - I am old now and there is no return. I just want to help others.' Sarda's executive director, Peter Pi Wing-lee, conceded some inmates at the Shek Kwu Chau centre took drugs. But he said 'we take this problem very seriously, and we do not tolerate anyone who takes drugs in our centre. About needle-sharing, it happens but it does not happen that frequently.' On average, more than 100 inmates a year are expelled after routine urine tests show they have taken drugs. So far this year, more than 70 inmates have been ejected. A study jointly conducted by the Department of Health and the University of Hong Kong in 1998 found 18 per cent of more than 1,300 drug users had shared needles with an average of three people. Department of Health figures showed that at the end of March this year, there had been 24 reported HIV infections due to drug injection. At least six of these people have now developed Aids and three were known to have died. In 1994, only about 0.05 per cent of all drug addicts were infected with HIV. The figure jumped to one per cent last year.