Sharing or being injected with the same needle and syringe is a huge risk for infection through blood to blood contact.
Any drug you use intravenously poses this risk. Image and performance enhancing drugs including steroid or botox injections can lead to hepatitis C infection. Rates of hepatitis C infection are much higher amongst people who use image and performance enhancing drugs than the in the general population. The Hepatitis C Trust is aware of instances were people are thought to have contracted the virus through botox injections.
If you are intravenously injecting drugs and share any injecting equipment, you can expose others to infection with hepatitis C. This applies to the needle and syringe, as well as to water, filters and spoons - even if you are using a new needle. Any needle that has been used before could still have invisible drops of blood attached to it. When this is placed in a spoon the blood can dissolve in the water and be deposited on the spoon or the filter ready for someone else to draw it up.
The best way to avoid transmitting the disease is to use new syringes, new needles, a clean spoon, sterile water and a new filter. If you do not have access to a new syringe and needle, thoroughly clean the ones you have. Hot water by itself will not kill hepatitis C and is not an efficient way of sterilising. Try as a minimum to use bleach, drawing it in and flushing it out several times. Remember, however, to do the same thing with hot water to flush out the bleach.
It is important to dispose of used needles carefully. The best place is a proper sharps bin, which you can get from your local needle exchange and some chemists. The next best thing is to recap the needle and put it in a sealed plastic container.
Drugs such as cocaine
If you share a rolled up note or straw for snorting drugs you risk exposing yourself and others to hepatitis C. This is especially true if your nose is bleeding. Cocaine in particular is very alkaline and corrosive to the thin membranes in the nose. If even tiny drops of your blood - often too small to see - get onto the straw or note, it is quite possible that blood to blood contact may take place through the nasal membrane.