Needle sharing is the practice of intravenous drug-users by which a needle or syringe is shared by multiple individuals to administer intravenous drugs such as heroin, steroids, and hormones. This is a primary vector for blood-borne diseases which can be transmitted through blood (blood-borne pathogens). People who inject drugs (PWID) are at an increased risk for Hepatitis C (HCV) and HIV due to needle sharing practices. From 1933 to 1943, malaria was spread between users in the New York City area by this method. Afterwards, the use of quinine as a cutting agent in drug mixes became more common. Harm reduction efforts including safe disposal of needles, supervised injection sites, and public education may help bring awareness on safer needle sharing practices.