The ratio of patients of drug users increases rapidly. Since 1984, incidence of infections through sexual contacts had accounted for 90% of all cases for most of time. But in 2005, drug using patients accounted for more than 50%. To prevent the disease from spreading to general population rapidly, the CDC announced the "Harm Reduction Pilot Projects for IDUs". The program includes expansion of the existing education and rehabilitation network, and the establishment of a harm reduction program unprecedented to the country.