The World Health Organization has called for all hospitals and clinics worldwide to adopt the use of “smart syringes,” which prevent a second use, by 2020. This, the agency argues, would reduce the spread of diseases such as HIV and hepatitis B and C (HBV and HCV).

A recent study published in PLOS ONE suggested that, in 2010, reused needles spread 1.7 million new cases of hep B around the world, as well as hundreds of thousands of cases of hep C and tens of thousands of HIV cases.

There are various kinds of smart syringes. Many of them prevent the plunger from being drawn back after the initial depression.

In 2000, WHO estimated that, in developing and transitional nations, unsafe injections were responsible for a respective 5 percent, 32 percent and 40 percent of new cases of HIV, HBV and HCV. Subsequent major safe injection campaigns have apparently been instrumental in reducing the absolute numbers of those new cases by 87 percent, 91 percent and 83 percent, respectively, in 2010—even in the face of a 13 percent growth in overall population. The hep B vaccine also contributed to the drop in new cases of that virus.