The need for an evidence-based approach to controlling opium production in Afghanistan.

Through both scientific evaluation (1), and the wisdom of experience (2), Western nations have learned that illicit drug markets are notoriously difficult to control from the supply side. A recent World Customs Organization report found that even post-September 11 security measures have had a ‘‘negligible’’ impact on the influx of illicit drugs into the United States (3). In Canada, we recently observed that a 100-kg heroin seizure, Canada’s largest in history, had no impact on the supply of heroin on the streets where the seizure occurred (3). The inability of law enforcement to control illicit drug markets has led to international calls for greater incorporation of scientific evidence of effectiveness into illicit drug policies (4,5). The heroin trade has serious international public health implications. In North America, injection drug use accounts for approximately one in four cases of human immunodeficiency virus (HIV), and in some areas where the virus is spreading rapidly, such as Russia, more than 80% of all HIV transmissions result from this behavior (6). In addition to HIV, hepatitis C virus is spread efficiently through the sharing of used needles, and the prevalence of hepatitis C is generally much higher than HIV among injection drug users (7). Illicit drug overdose deaths from injection drug use are also among the leading causes of mortality in many large North American cities (8). In this context, the United Nations Office on Drugs and Crime (UNODC) reported in 2006 that Afghanistan’s opium poppy crops are the source of 92% of the world’s supply of heroin and that this figure is projected to increase in the coming years (9). Within Afghanistan, the booming illicit drug industry makes up