Sterile Injection Practices: Safety Principles from CDC and WHO

There are some risks associated with every injection procedure which do not depend on what the injected substance is. Infections, injuries from the needle, and cross-contamination are to be expected, provided proper sterile injection procedures are observed. Various organizations worldwide, such as the CDC and WHO have published comprehensive instructions regarding safe administration of injections, and while this section provides summarized instructions, it does not describe the technique of injecting specific substances.

Sterile Injection Principles from Primary Sources

2 organizations provide the foundational guidance on injection safety worldwide. Their recommendations overlap significantly, and both emphasize the same core principle: one needle, one syringe, one patient, one time.

CDC Safe Injection Practices (2007, Updated)

The CDC published its Safe Injection Practices guidelines as part of the Standard Precautions framework. The document addresses healthcare settings but its principles apply universally. Key recommendations include: use a new needle and syringe for each injection, never reenter a medication vial with a used needle, use single-dose vials whenever possible, and discard multi-dose vials 28 days after opening regardless of remaining contents.

The CDC also runs the One and Only Campaign, which combats unsafe injection practices that still cause outbreaks in health care settings. From 2001 to 2011, there were at least 49 outbreaks of hepatitis B and hepatitis C in the US due to lapses in injection safety practices. I mention this figure as it shows that even trained health care workers are not always capable of following sterile procedures. These guidelines are needed because compliance is not inevitable.

WHO Best Practices for Injections (2010)

In 2010, the World Health Organization published a booklet entitled Best Practices for Injections and Related Procedures. The handbook addresses the areas of prevention of sharp injuries, single-use devices specifications, waste disposal and infection control. The WHO framework is broader than CDC’s in scope and emphasizes poorer countries where the reuse of syringes is prevalent. The main recommendation of the WHO is similar to that of CDC; that is, no injection instruments should be reused.

A risk classification system for injection practices was also developed by the World Health Organization. Reusing syringes or needles in practices is classified under the highest risk level. Reusing a needle on the same person with a different vial is classified as medium risk. Reusing on one individual however is no guarantee against introduction of contaminating vectors, which are considered unacceptable in every injection situation.

One Needle, One Syringe, One Use

Why Reuse Causes Bloodborne Pathogen Transmission

A used needle or syringe can harbor microscopic quantities of blood, even when no blood is visible. Hepatitis B virus can survive on environmental surfaces for at least 7 days. Hepatitis C virus can persist in syringes for weeks. HIV, while less resilient outside the body, has been transmitted through shared injection equipment in documented cases.

The procedure is simple. A needle is put into the tissue, causing it to run into blood. The needle is then reinserted into a bottle, which lets blood mix with the medication. This causes the next dose drawn from the bottle to be contaminated. The whole cycle is responsible for epidemics in hospitals, outpatient facilities and in the street needle exchange programs. Contamination can't be seen. The only way to avoid this is to use needles only once.

Single-Use Syringe Design Features

Syringes that have been designed in modern times include characteristics that discourage their reuse or any possibility thereof. Syringes that have retractable tubes retract the tubes into the barrel after the injection has taken place. Syringes that are auto-disable types lock the plunger in place following one use only, making it impossible to draw the liquid again from the same syringe. The World Health Organization recommends the use of auto-disable syringes for vaccination campaigns as these syringes help eliminate the possibility of reuse.

In laboratories it is common practice to use disposable syringes without features designed to prevent their reuse. While it is possible to reuse such disposable syringes, it is not recommended. A used needle loses its sharpness after just one use causing it to inflict more tissue damage and pain upon reinsertions into the skin. We have read forum comments made by people who reused syringes which has convinced us to stress this point.

Vial Handling and Aseptic Technique

Vials are often overlooked as a potential source of contamination. Every time a needle is passed through the rubber seal of a vial, there is an opportunity for bacteria to get into the vial. Correct handling of vials is an essential aspect of sterile injection procedures.

Swabbing the Vial Stopper

Prior to inserting the needle, disinfect the rubber cap with a 70% isopropyl alcohol swab. Wait until the alcohol completely evaporates prior to inserting the needle. Wet alcohol on the needle can cause pain during injection and can also contaminate liquid inside the vial with surface bacteria. This procedure takes about 10 seconds to eliminate germs brought about by manipulation, as well as by dust particles, airborne contaminants and prior needle punctures.

Single-Dose vs Multi-Dose Vials

Single-dose vials are made for use with one needle only and can be used only once. A preservative is not used in this kind of vial since it is not meant for storage. Multi-dose vials consist of preservative from 0.9% benzyl alcohol that is meant for antibacterial purpose.

The CDC suggests that single-dose vials must be used wherever feasible. When multi-dose vials are used, they should be maintained according to the manufacturers' instructions, must never be used after the beyond-use date, and must be discarded if sterility is questionable. This is deemed as the most important step for anyone who handles injectable drugs.

Storage After Opening

Sharps Disposal

FDA-Cleared Sharps Containers

Sharps disposal containers should be used for the disposal of used syringes, needles and lancets. The FDA approves the use of thick plastic containers that have tough edges that will not allow for any leaks or seepage of their contents and have very secure lids. These containers can be purchased from any pharmacy. However, if a commercial sharps container is not available, the FDA recommends using a solid household plastic bottle that can be tightly capped to dispose of sharp objects.

Do not throw away loose needles in bins for garbage or recycling, as well as in receptacles which can be accessed by others. The health risks of improperly disposed needles are documented. So sharp waste disposal is something that can be done easily and is also improperly ignored.

Community Disposal Programs

A number of neighborhoods have sharps disposal programs available through pharmacies, medical facilities, health agencies, or mail back services. The United States FDA company has a repository for states’ disposal procedures and regulations. A number of states obligate a pharmaceutical take-back program with acceptance of sharps containers. Be sure to take a look at your local rules concerning the matter before you collect containers at home.

Signs That Require Medical Attention

Good sterilization practices decrease the risks involved but don't eliminate all hazards. If complications are recognized early, better outcomes may result.

Infection Warning Signs

Redness radiating from the site of injection, especially streaks of red coming outwards. Increase in pain which gets worse instead of better with passing time in course of 24 hours. Added warmth and swelling of the site. Presence of pus and leaking or bad smell. Emergence of fever reaching the mark of 38C (100.4F) in the course of 48 hours would be reason enough for consultation.

Allergic Reaction Indicators

Hives, widespread itching, swelling of the face, throat constriction, or breathing difficulty are signs of an allergic reaction that may appear within minutes to hours of the injection. Anaphylaxis is a major medical problem that can occur with any injectable drug, including diluents and preservatives. Benzyl alcohol, which can be found in bacteriostatic water, is an allergen in some cases.

Nerve or Vascular Injury

The experience of intense, piercing discomfort extending from the injection area at the time of needle insertion could suggest the involvement of a nerve. Incidents of loss of sensation, tingling or decrease in strength must be assessed. Great bleeding or fast-growing hematoma indicates damage or injury to blood vessels. Such incidence is rare with small-diameter needles in the subcutaneous tissue while it can happen while making deeper intramuscular injections.