Other methods of preventing HIV transmission include those transmissions from injecting drug use. Commonly, people share the needles after they inject their drug into their vein, the next person uses the same needle, draws up some more drug injection into their own vein. That means blood has been shared by directly into the vein, and if one person is infected then the other person has a very good chance of becoming infected. The infection rate in some injecting drug use populations is 60% or more from HIV. Other diseases get transmitted that way too including Hepatitis C, among others. So how do we prevent injecting drug use is a great question. We have huge programs to ban the importation and distribution of drugs that are deemed illegal. Commonly, they're used intravenously, for example, heroin, and sometimes cocaine can be used intravenously methamphetamine, can be smoked but also can be injected intravenously. So our government has been very busy trying to shut down all these drug operations and unfortunately has not been very successful. So what's left? Taking it down to the end user, one way is to provide everybody with sterile needles that can be disposed of after each and every use. So the problem is that, politically, it's been determined that making needles freely available will encourage drug use, and so, there are laws usually restricting the sale of medical syringes and needles. Therefore, one other possibility is to have a needle exchange program. An injecting drug user can bring in his old needles which will then be properly disposed of and get one clean needle for every dirty needle that he brought in. This is a no-questions-asked situation. It's been fought against by many politicians and other leaders for many years, but in some places there's been some progress and needle exchange programs have been allowed by law in some areas. They should be effective, in terms of at least giving clean needles, the problem is of course it's not clear that each needle will be used only once, and so we're perhaps best if we have people to ensure that they have clean needles by sloshing some bleach water in and out of their syringe and needle prior to using it. Again, the difficulty is that would work is no question it can work. But remembering that we're talking about injecting drugs that affect people's brains and how they think and feel, and they in essence if they're high and otherwise not thinking properly, they may not take the time to wash out the needles between injections, for example. Drugs such as cocaine keep people awake. They also are very short acting, so people may inject 10 times in one session whereas heroin makes people sleepy, they may inject once every several hours. So the end result is there may be more opportunity for injecting dirty needles if someone is in a cocaine run, or methamphetamine run, constantly up, constantly shooting, constantly doing something, and also constantly not thinking properly. So it's difficult on the injecting drug side of things.