It is estimated that there were 13.2 million injecting drug users (IVDUs) worldwide at the end of 2003. Around 78% of these people were living in developing and transitional countries. Around 25% of all injecting drug users live in South and South-east Asia, and a further 18% in East Asia. Both China and India are home to more than a million IVDUs. The world's highest rates of HIV infection among IVDUs are found in Asia. By 1999, drug-dependent individuals comprised about 77% of HIV infections in Malaysia and 69% in China, and 66% of AIDS cases in Vietnam. A further 24% of injecting drug users are found in Eastern Europe and Central Asia. There are around two million in Russia, 397,000 in Ukraine and 174,000 in Kazakhstan. IVDUs account for 82% of all HIV/AIDS cases in Central Europe and Former Soviet Union states (Centres for Disease Control and Prevention: HIV/AIDS Surveillance Report 2002).

North America and Latin America respectively account for 10.6% and 7.6% of injecting drug users. There are around 1.3 million in the USA, 800,000 in Brazil and 153,000 in Canada. Injecting drug use has caused about 20% of all adult HIV infections reported in the USA. In 2002, it was estimated that this same route accounted for 40% of new infections in Argentina and 28% in Uruguay. Around 9.4% of IVDUs live in Western Europe, where populations above 200,000 exist in Germany, Italy and Spain. In 2002, a little more than one in ten newly diagnosed HIV cases in Europe were caused by injecting drug use. However, in Portugal, this mode of transmission caused almost half the total HIV infections in 2002 (UNAIDS 2003 Fact sheet 'High-income countries).

The use of opiates has been increasing worldwide with more than two-thirds of the countries in the world reporting increases. Opiate use is highest in developing nations and nations in transition, while use in developed nations is stable or declining. One possible reason for the increase in use worldwide is that production of opium has increased dramatically. Opium and opiate drugs are most widely used in Asia. Opiate use is much lower in North America, Central America, South America, and Europe than it is in Asia. However, there is still enough use to consider opium a problem drug in those regions. Africa has the lowest overall use of opium (Carmen 2004)

Cannabis remains the most widespread drug in use worldwide. The United Nations World Drug Report estimates that cannabis is the most widely abused substance in all parts of the world, with around 141 million people using it. The use of cannabis is increasing overall, but in some regions, notably North America, Russia, China, and parts of Asia, use has stabilized or decreased in recent years. Cannabis will probably remain the most widely used drug because the crop is easily grown in many different climates and requires no processing for use as drugs. The major growers of cannabis and major suppliers for the world market are Morocco, South Africa, Nigeria, Afghanistan, Pakistan, Mexico, Colombia, and Jamaica. Another trend in cannabis growing in developed nations is hydroponics and other indoor growing techniques. Improved cannabis growing techniques result in a plant with a much higher concentration of tetrahydrocannabinol, the active ingredient in marijuana and other cannabis drugs. As a result, the drugs from these crops are more powerful.

Throughout the 1990s, the use of amphetamine-type stimulants (ATS) increased dramatically worldwide. The main regions of use of ATS are in North America, Western Europe, and Asia. By the end of the 1990s, ATS use had stabilized or declined in North America and Western Europe. By contrast, use has continued to increase in Asia. Asia is the leading region for use and manufacture of ATS, and the potential for spreading the problem to other regions continues (Carmen 2004).

Worldwide, cocaine use has been reported in more than two- thirds of all countries. Although the use of cocaine is declining in North America, the rate of use still leads the world. In Western Europe, cocaine use has continued to rise since 1980. The lowest rates of cocaine use are found in Asia. Law-enforcement efforts have brought down the rate of production in cocaine-producing nations in recent years. Cocaine use is highest in the United States, but use is also high in other countries throughout the Americas and Europe. In general, rates of cocaine use are higher in more affluent countries. The use of amphetamine-type stimulants is highest in Europe and significant in selected other countries in the Americas. African countries generally show more amphetamine-type stimulant use than use of opium and cocaine, where use is low. Cocaine use in Spain has overtaken the United States and left Britain and Ireland behind, with the proportion of people who use the drug rising to more than one in 40. "Spain occupies the top place in the world," the report said, citing United Nations figures on cocaine use around the globe. The reason for such a high rate in Spain is that much of Europe's cocaine is unloaded on to Spanish beaches (El Pais Newspaper, Sept 2005)

Countries differ in the timing of the introduction of HIV into the drug using population and levels of HIV infection in this population. In some countries where injecting drug use is found, such as Hong Kong, Nepal, and Singapore, HIV seroprevalence is virtually nonexistent, while in other areas, such as Brazil, Thailand, Manipur, and Yunnan Province, China, levels of HIV infection in IDUs are reported to have stabilized at 50 percent or higher in some cases (Stimson 1993, Poshyachinda 1993).

References

Carmen, A et al. Global overview of injecting drug use and HIV infection among injecting drug users. On behalf of the UN Reference Group on HIV/AIDS Prevention and Care among IDU in Developing and Transitional Countries, 2004.

Centres for Disease Control and Prevention: HIV/AIDS Surveillance Report 2002.

Poshyachinda, V. Drug injecting and Hiv infection among the population of drug abusers in Asia. Bulletin on Narcotics. XLV(1): 77-90, 1993.

Stimson, G.V. The global diffusion of injecting drug use: implications for human immunodeficiency virus infection. Bulletin on Narcotics. XLV(1): 3-17, 1993.

UNAIDS/WHO 'AIDS epidemic update', December 2002

UNAIDS 2003 Fact sheet 'High-income countries'