The "War on Drugs" has failed, particularly with regard to the spread of HIV in middle-income nations and some developing nations in Asia. The disease is now starting to bleed into Africa as well.

The spread of HIV among injection drug users is a most crucial issue in middle-income countries: poor nations simply cannot afford so expensive a vice on a large scale, and affluent nations often have instituted harm-reduction policies, such as needle exchange and opioid substitution programs, to mitigate the health risks

An estimated five million people have become infected with HIV through injection drug use (IDU) worldwide; nearly half of them are in China, Vietnam, Russia, Ukraine and Malaysia—almost all of which could be considered developing nations (Russia has propped up its faltering economy with the foreign exchange of oil sales). IDU is the principle vector for the epidemic in most of the nations of the former Soviet Union.

Injection drug use has become a growing problem in Africa along recently established transit routes for cocaine from South America, and to a lesser extent along routes for heroin from Asia. Those transit points are seeing emerging injection drug use, spurred on by the fact that locals running the drug routes are often as likely to be paid with a portion of the stash as with cash.
Despite massive investments in drug law enforcement in the past three decades, with much of the international interdiction effort paid for by the U.S. government through assistance to national military and police forces, there is "a general pattern of falling drug prices and increasing drug purity" throughout the world, according to the Vienna Declaration.

The petition drive, launched this summer at the International AIDS Conference in Vienna, Austria, aims to reorient government policies on injection drug use from focusing on prohibition, law enforcement and incarceration to focusing on treating addiction as a medical problem with medical solutions.

The extensive criminalization of illicit drug users is fueling the HIV epidemic and has resulted in overwhelmingly negative health and social consequences, says the declaration.

"These policies fuel the AIDS epidemic and result in violence, increased crime rates and destabilization of entire states," said Julio Montaner in a prepared statement. He is one of the leaders behind the declaration, past-president of the International AIDS Society and director of the British Columbia Centre for Excellence in HIV/AIDS in Canada.

HIV is a blood-borne disease, and when street drugs such as opioids, amphetamines and cocaine are injected into a vein, a small amount of blood—and the virus, if present—often is drawn back into the syringe or remains on the outside of the needle.

HIV can be transmitted to another person who uses that needle. In fact, the odds of transmission are much higher from injection drug use than from sex because the needle bypasses the skin or mucosal tissue, which have passive barrier and active immune functions that can offer some protection against infection.   

Some people share needles for communal or ritualistic reasons, much like passing around a marijuana joint. But given the widely known risks of transmitting HIV, hepatitis and other infections, the most common reason why people continue to share needles is the unavailability of other syringes. The shortage can be due to cost or prohibitionist policies, such as requiring a prescription to obtain a needle or the presence of a needle as evidence of illegal activity. 

Needle exchange programs that make clean syringes more readily available have demonstrated success in decreasing the rate of new HIV infections among injection drug users. But these approaches often are met by community resistance because of the stigma associated with drug users and fears of crime associated with drug dealing.

Regardless of whether one uses injection drugs, there are practical reasons why everyone should be concerned with HIV within the injection drug community. Most obvious is that injection drug users have sex with non-users, and the virus can spread to their partners and children.
Biologically, HIV is a constantly mutating virus. The greatest changes in viral diversity occur when two separate strains of the virus infect the same cell and a new combination strain emerges from that cell. Simultaneous exposure to two or more strains of HIV most efficiently occurs when syringes are shared between injection drug users.

"What is needed is a massive scale-up of combination prevention, treatment, and care. In opioid-driven epidemics, this approach includes an essential minimal package of safe injection programs, opioid substitution therapy [such as methadone], and antiretroviral treatment" for their HIV infection, according to a panel of experts in a recent series of papers appearing in the journal The Lancet.

They noted that "there are synergies between biomedical science, public health, and human rights" in implementing this approach to substance abuse and HIV.

Examples from Europe, Brazil, Hong Kong and several U.S. cities show that a package of harm-reduction interventions recommended by the World Health Organization (WHO) can keep the rate of new HIV infections low and stable among injection drug users for many years and not result in increased drug use.

Portugal is an example of what a comprehensive drug reform policy can accomplish. Beginning in 1999, the country decriminalized personal possession and consumption of drugs and began to treat drug addiction as a medical rather than a legal or police problem.

Overall, drug use there among persons aged 15–19 declined from 10.8 percent in 2001 to 8.6 percent in 2007, whereas the portion of new HIV infections attributed to IDU fell from 54 percent to 30 percent over the same period.

Similar treatment strategies have also helped to decrease HIV infections by 80 percent among injection drug users in the U.S. They now constitute just 12.9 percent of all new infections each year.