Over 70 percent of amphetamines seizures around the world have been in the countries of eastern and southeastern Asia, mostly China and Thailand. Cambodia is still the main supplier of cannabis, particularly for the local region. China has now become the main destination and transit region for heroin, which also explains the fact that over the past five years, seizures of heroin in that country have increased by a considerable amount. The use of drugs is also expected to rise in Afghanistan following the return of refugees from regions where poppies are cultivated and opium and heroin are manufactured. Of particular concern is the increasing incidence of the AIDS virus along the drug distribution routes in eastern and southeastern Asia. In some parts of China, the number of AIDS sufferers has reached epidemic proportions among intravenous users, while one in two users in Myanmar and Thailand is HIV positive.