Mainland drug users are estimated to be sharing more than half a million needles every day, which one Aids expert says remains the country's main cause of HIV transmission. Officials are eager to reduce such high-risk behaviour by increasing access to clean needles. The number of registered drug addicts on the mainland rose from 70,000 in 1990 to more than 900,000 last year. Among them, 450,000 use intravenous drugs and half of these people, or about 225,000, share needles. Wu Zunyou, a research scientist at the National Centre for Aids Prevention and Control, said methadone programmes and increased access to clean needles would provide new hope in the fight to control the epidemic. Among the 30,736 officially registered HIV/Aids patients in China by the end of last year, 68 per cent had contracted the virus through needle sharing. Blood donations accounted for 9.7 per cent of cases and unsafe sex for 7.2 per cent. Dr Wu said that as each drug addict injected two or three times a day, needles are shared on average between 450,000 and 675,000 times daily. The Guangdong government has introduced a drive to increase the number of shops selling clean needles. In the past, only licensed medical equipment shops could sell needles, but the local government has relaxed the restriction to allow some drug stores to do so. The province recorded more than 1,800 HIV infections between 2000 and 2001. Of these, 81.3 per cent contracted the disease through drug use. Officials estimate 53 per cent of drug addicts in the province share needles. Dr Wu said the migrant population also needed more Aids education because many belonged to high-risk groups, including sex workers. 'The tricky nature of Aids makes control difficult. People infected with HIV have no symptoms for eight to 10 years and can continue work but spread the virus to others,' he said. He also said Aids remained a taboo subject, adding: 'Some people refuse to receive promotional information about Aids. They worry if they are seen accepting this material, they will be seen as a patient, or having bad behaviour.' One mainland official said it was worrying that even her colleagues in the health-care field were afraid of Aids. 'One of my colleague was sick and there were rumours about her contracting HIV. Some very educated officials refused to visit her in the hospital,' she said.