How and why AIDS changed drug policy in Switzerland.

Switzerland implemented a harm reduction program and reduced the spread of HIV within the drug scene, and from drug users into other population groups, earlier than many countries. Each canton developed strategies based on its drug problem. By 1985 it was obvious that 'needle sharing' was the most significant pathway in the transmission of HIV. Some cities established Drug Consumption Rooms and small-scale syringe exchange programs. However, a dramatic concentration of drug use in the Platzspitz (a park) of Zürich evolved where 1000-2000 drug users gathered daily, many of whom were infected with HIV. The Federal Office of Public Health financed needle exchange and other harm reduction programs, with evaluation. Within a few years the Swiss established low-threshold methadone treatment programs and Heroin-Assisted Therapy. In 2008, the Swiss approved a law based on the principles of a 'four pillar system': repression, prevention, harm reduction, and treatment.