Sharing a used needle, syringe or any other injecting equipment - including water, alcohol swabs, filters, spoons, tourniquets and so forth - with another person is a very effective method of transmitting a blood borne virus, including Hep C, Hep B and HIV (the virus that causes AIDS). If you share injecting equipment (including needles and syringes) with anyone infected with HIV or Hep C, the likelihood of becoming infected is extremely high. You can pass the virus on to others the same way. It is impossible to tell by looking at someone whether they have any of these viruses.

The prevalence of HIV/AIDS is very high among injecting drug users in many other countries, including the USA. Although the spread of HIV has slowed considerably in the USA - for example, seroprevalence has decreased in New York City from approximately 55-60% of injecting drug users in the early 1990's to around 15% today - injecting drug use still accounts for one in four of all HIV infections and HIV/AIDS is still a major public health problem.

In many other parts of the world, for example in Malaysia, Viet Nam, and Yunnan province in China, injecting drug use is the major mode of HIV transmission. In the Russian Federation, more than half of all reported HIV cases to date have been among injecting drug users.

Fortunately, the situation in Australia is very different. In fact, Australia has a well-deserved reputation in the international community for its prompt and innovative response to HIV/AIDS. Due to the implementation of a range of harm reduction measures (e.g. needle/syringe programs, drug user organisations like VIVAIDS and peer education programs about safer drug use, etc) infection rates have been prevented from rising above 2% among injecting drug users in this country. Ultimately, however, an HIV epidemic was prevented because drug users in Australia changed their injecting practices and educated themselves and each other about safer drug use.

Refusing to use someone else's pre-used syringe or needle doesn't mean you don't trust them; it means you are protecting yourself and your future sexual and/or drug use partners. As well as preventing HIV and Hep C, using new equipment every time you inject means that you are also protecting yourself from a range of other drug related harms including endocarditis, blood poisoning, vein damage and scarring.