A chacun sa couleur


Reuse and sharing of needles and syringes

Sharing needles and syringes is less prevalent than sharing of other injection paraphernalia (Strike et al., 2010), but it is still quite common. In Scotland (Scott, 2008), 10-12% of people who inject drugs (PWID) used someone else’s syringe in the last month and 8-12% have kept their syringe for someone else to use. In addition, 65-70% of the people kept their own needles for reuse. In a prospective multicentric study in the US, Hagan et al. (2010), found that 49% of the people had used a syringe previously used by others during a study period of 6 months up to 1 year; Strike et al. (2010) found that 36% of PWID in English speaking Canada reported distributive needle sharing. In France, an estimated 170 syringes are distributed or sold per person who injects drugs, which equals less than half a syringe per person per day (INSERM, 2010). One can easily imagine that reuse (or sharing) of syringes remains very high.

In addition to "deliberate" or "knowledgeable” syringe sharing (which may be due to a lack of equipment available at a given time and place), some situations foster confusion. One can think of a festive atmosphere, or the presence of a large quantity of paraphernalia resulting in confusion about their ownership during group injection, the context of intensive use or psychoactive effects of substances...

A survey in France (Debrus, 2008) showed that the vast majority (85%) of PWID has already injected in the presence of other injectors and 45% of them have ever had doubts as to the ownership of the equipment used. Distribution of tools with different colours can allow PWID to differentiate their tools from those of others. Even if the main goal remains single use of sterile paraphernalia, reuse is rather a rule than an exception (Debrus, 2008), the colours will enable one to reuse his own material. The colours also visually support the message not to share equipment.

Preference for syringe type and dead space

Syringes without an attached needle are sometimes preferred by PWID because these are available in all sizes (2 ml, 5 ml, etc.) and because they enable the use of different types of needle (the type of needle used depends on the injection site, vein health, the type of drug used…). Though it is important to provide the tools needed by clients, the use of these syringes should be discouraged.

One of their major disadvantages is that they have a much higher dead space or void volume, which means that they contain much more fluid once the plunger is fully depressed (Heimer & Abdala, 2000; Zule et al., 1997). This fluid can be almost entirely composed of blood due to the process of "booting”: after injection, the person pulls up the plunger to mix the last bit of drug with his/ her blood and reinject.

Even if a syringe is subsequently rinsed, in the case of (accidental) sharing, the risk of viral transmission is higher when detachable syringes are used (Bobashav & Zule, 2010, Gyarmathy et al., 2010 ; Zule & Bobashev, 2009 ; Zule et al., 2002). Indeed, both HIV and hepatitis C virus have been found present in higher numbers. They also survive for longer periods of time in high dead space (HDS) syringes and are more infectious at all times (Heimer & Abdala, 2000; Paintsil et al., 2010)

Retractable syringes or difficult to use syringes

Different types of self-destructing or difficult to use syringes exist. The general purpose of these syringes it that they can’t be used a second time. Different mechanisms exist to obtain this (according to US Congress, 1992, Des Jarlais et al.).

  • A hydrophilic gel is placed inside the syringe. In contact with the solution to be injected, this gel expands and disables the plunger or closes the passage way through the needle.
  • The plunder is disabled when the user attempts to reload the syringe for a second time. Often, this design is easy to defeat.
  • The needle is disabled after a first use. This mechanism often only works when the user chooses to actively disable the needle so that someone who does not want to do disable the syringe does not have to. The advantage of these syringes is thus not the prevention of reuse or viral infections, but the prevention of needle stick injuries.
  • Syringes that have valves with a one-way flow mechanism. These syringes can be loaded and emptied, but not reloaded.

None of these syringes is 100% perfect; the mechanism can always be defeated.

The use of auto-disable syringes to prevent transmission of blood-borne illnesses among PWID has been proposed and rejected in the Netherlands, Australia and the United States (US Congress, 1992; Des Jarlais et al). Apothicom subscribes to their position and to the one of the Harm Reduction Coalition[1] and chooses not to commercialise this type of syringe for the following reasons (described in more details in the report of the US Congress, 1992; Des Jarlais et al.):

  • First of all, all mechanisms can be defeated. As people can thus choose to reuse them again, these (more expensive) syringes do not have a high added value
  • To defeat these mechanisms, some syringes need to be taken apart, increasing the risks of injury and bacterial contaminations due to manipulation
  • To be able to reuse some of these syringes, the plunger should not be inserted completely, which increases the syringe’s dead space which can actually increase viral risk in case of sharing
  • The syringes distributed to PWID do not cover the needs. "One syringe for every injection” is simply not available. When "difficult to use syringes” are given out, the quantity that needs to be provided to avoid scarcity of syringes is much higher (more than 700 syringes per PWID per year). As this is probably impossible to do in most contexts, scarcity will increase the value of other, reusable syringes. "This situation might actually lead to more multiperson use (sharing) of illicit drug-injection equipment and hence an increase in HIV transmission among injecting drug users” (US Congress, 1992; Des Jarlais et al).

This rationale is corroborated by a mathematical modeling study performed by Caulkins et al. (1998). They showed that replacing standard syringes with auto-disable syringes will be likely to increase the incidence of HIV among injection drug users.

Viral contaminations due to the reuse and sharing of needles and syringes

The presence of HIV (antibodies, DNA or RNA) has been detected in 20-94% of the used syringes examined by Chitwood et al. (1990), Kaplan and Heimer (1995) and Shah et al. (1996).
When one focuses on the viability of the virus inside the syringe, that is to say, the presence of virus that has the ability to cause infection, HIV is found in higher numbers and remains alive for a longer period of time in high dead space syringes (those with detachable needles, the so called Luer syringes) than in low dead space syringes (Heimer & Abdala, 2000; Zule et al., 1997; Zule et al., 2013). In the case of (accidental) sharing, the risk of viral transmission is thus higher with these syringes.

The hepatitis C virus (HCV) is more virulent and infectious than HIV. HCV has been detected in 70% of the used syringes examined by Crofts et al. (2000). Inside syringes without an attached needle, this virus remains infectious for 63 days, while syringes with an attached needle no longer contained viable virus from the second day on (Paintsil et al., 2010). In the field, needle sharing has been confirmed as a risk factor for the transmission of hepatitis. C. Pouget and Others (2011) conducted a meta-analysis of 21 different scientific studies and found that needle sharing is associated with the transmission of hepatitis C (relative risk of 1.97).

Bluthenthal et al. (2007) found that, in general, the number of syringes distributed should cover at least 100% of the needs; less coverage increases paraphernalia sharing and therefore the risk of contamination.

Other infections and overall risks associated with needle and syringe reuse.

The reuse of unclean syringe can also induce bacterial infections with sometime serious health consequences (abscesses, endocarditis, septicaemia ...). Most of these bacteria come from the skin or saliva of PWID themselves. Fungal infections can also be transmitted when a person licks the needle before injection (Gambotti et al., 2006).

When syringes or needles are reused, the needle becomes blunt (figure 1) and can damage the skin and veins, which increases the risk of infections (Kaushik et al., 2001).

Figure 1.

From the left to the right: a new syringe and a syringe that has been used 6 times

In general, even with the proper equipment and impeccable consumption hygiene, injection is never without risks. In addition to the damage that can be caused by the drugs, tablet fillers or cuttings, injection often leads to a deterioration of the venous condition. Many PWID encounter difficulties injecting, bruises or thrombosis (Cadet Taïrou et al., 2008; Salmon et al., 2009).


  • To reduce the risk of transmission or contamination, each injection should be made with a sterile syringe. Sterile syringes should be provided in the quantities requested by clients, without limitation.
  • Ideally, the number of syringes distributed should cover more than 100% of needs (syringes may be lost or confiscated and some PWID need more than one syringe to find a vein).
  • Do not force people to return used needles, but encourage them to do so.
  • Procedures for cleaning syringes can reduce the amount of pathogens and viruses, but are unable to completely eliminate them.
  • Provide needles and syringes in the sizes that meet the needs of clients to avoid losing contact with them, but continue to inform them about the differences and the safer options.
  • Encourage participants to use low dead space syringes.
  • Provide needle exchange services in places where they are needed and with opening hours that are adapted to the drug using context.
  • Provide general harm reduction information and services (social, legal, and health services).
  • Provide, besides needles and syringes, other paraphernalia, such as sterile cookers, filters, acid, water for injection, alcohol swabs, condoms, etc..


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