Needlestick injury

Cause

Needlestick injuries are a common event in the healthcare environment. When drawing blood, administering an intramuscular or intravenous drug, or performing any procedure involving sharps, accidents can occur and facilitate the transmission of blood-borne diseases. Injuries also commonly occur during needle recapping or via improper disposal of devices into an overfilled or poorly located sharps container. Lack of access to appropriate personal protective equipment, or alternatively, employee failure to use provided equipment, increases the risk of occupational needlestick injuries. Needlestick injuries may also occur when needles are exchanged between personnel, loaded into a needle driver, or when sutures are tied off while still connected to the needle. Needlestick injuries are more common during night shifts and for less experienced people; fatigue, high workload, shift work, high pressure, or high perception of risk can all increase the chances of a needlestick injury. During surgery, a surgical needle or other sharp instrument may inadvertently penetrate the glove and skin of operating room personnel; scalpel injuries tend to be larger than a needlestick. Generally, needlestick injuries cause only minor visible trauma or bleeding; however, even in the absence of bleeding the risk of viral infection remains.

Epidemiology

In 2007, the World Health Organization estimated annual global needlestick injuries at 2 million per year, and another investigation estimated 3.5 million injuries yearly. The European Biosafety Network estimated 1 million needlestick injuries annually in Europe. The US Occupational Safety and Health Administration (OSHA) estimates 5.6 million workers in the healthcare industry are at risk of occupational exposure to blood-borne diseases via percutaneous injury. The US Centers for Disease Control and Prevention (CDC) estimates more than 600,000 needlestick injuries occur among healthcare workers in the US annually.

Among healthcare workers, nurses and physicians appear especially at risk; those who work in an operating room environment are at the highest risk. An investigation among American surgeons indicates that almost every surgeon experienced at least one such injury during their training. More than half of needlestick injuries that occur during surgery happen while surgeons are sewing the muscle or fascia. Within the medical field, specialties differ in regard to the risk of needlestick injury: surgery, anesthesia, otorhinolaryngology (ENT), internal medicine, and dermatology have high risk, whereas radiology and pediatrics have relatively low rates of injury.

In the United States, approximately half of all needlestick injuries affecting health care workers are not reported, citing the long reporting process and its interference with work as their reason for not reporting an incident. The availability of hotlines, witnesses, and response teams can increase the percentage of reports. Physicians are particularly likely to leave a needlestick unreported, citing worries about loss of respect or a low risk perception. Low risk perception can be caused by poor knowledge about risk, or an incorrect estimate of a particular patient's risk. Surveillance systems to track needlestick injuries include the National Surveillance System for Healthcare Workers (NaSH), a voluntary system in the northeastern United States, and the Exposure Prevention Information Network (EPINet), a recording and tracking system that also gathers data.

Non-healthcare injuries

Blood on any sharp instrument may be infectious, whether or not the blood is fresh. HIV and hepatitis C virus are only viable for hours after blood has dried, but hepatitis B virus is stable even when dried out. Therefore, other professions may experience a risk of needlestick injury, including law enforcement, waste collectors, laborers, and agricultural workers. Law enforcement workers, like healthcare workers, underreport needlestick injuries. In San Diego, 30% of police reported needle sticks. A study of 1,333 police officers in the Denver Police Department found that only 43.4% reported a needlestick injury they received; 42% of which occurred during their evening shift. Most of the needlestick injuries experienced by these workers occurred in their first 5 years of employment. In New York City, a study found a rate of 38.7 exposures (needlesticks and human bites) per 10,000 police officers.

Treatment and prognosis

While needlestick injuries have the potential to transmit bacteria, protozoa, viruses and prions, the risk of contracting hepatitis B, hepatitis C, and HIV is the highest. The World Health Organization estimated that in 2000, 66,000 hepatitis B, 16,000 hepatitis C, and 1,000 HIV infections were caused by needlestick injuries. In places with higher rates of blood-borne diseases in the general population, healthcare workers are more susceptible to contracting these diseases from a needlestick injury.

Hepatitis B carries the greatest risk of transmission, with 37-62% of exposed workers eventually showing seroconversion and 22-31% having symptoms. Higher rates of hepatitis B vaccination among the general public and healthcare workers have reduced the risk of transmission; non-healthcare workers still have a lower HBV vaccine rate and therefore a higher risk. The hepatitis C transmission rate has been reported at 1.8%, but newer, larger surveys have shown only a 0.5% transmission rate. The overall risk of HIV infection after percutaneous exposure to HIV-infected material in the health care setting is 0.3%. Individualized risk of blood-borne infection from a used biomedical sharp is further dependent upon additional factors. Injuries with a hollow-bore needle, deep penetration, visible blood on the needle, a needle located in a deep artery or vein, or a biomedical device contaminated with blood from a terminally ill patient increase the risk for contracting a blood-borne infection.

After a needlestick injury, certain procedures must be followed to minimize the risk of infection. Lab tests of the recipient should be obtained for baseline studies, including HIV, acute hepatitis panel (HAV IgM, HBsAg, HB core IgM, HCV) and for immunized individuals, HB surface antibody. Unless already known, the infectious status of the source needs to be determined. Unless the source is known to be negative for HBV, HCV, and HIV, post-exposure prophylaxis (PEP) should be initiated, ideally within one hour of the injury.

Hepatitis B

After exposure to the hepatitis B virus (HBV), appropriate and timely prophylaxis can prevent infection and subsequent development of chronic infection or liver disease. The mainstay of PEP is the hepatitis B vaccine; in certain circumstances, hepatitis B immunoglobulin is recommended for added protection.

Hepatitis C

Immunoglobulin and antivirals are not recommended for hepatitis C PEP. There is no vaccine for HCV; therefore, post-exposure treatment consists of monitoring for seroconversion. There is limited evidence for the use of antivirals in acute hepatitis C infection.

HIV

If the status of the source patient is unknown, their blood should be tested for HIV as soon as possible following exposure. The injured person can start antiretroviral drugs for PEP as soon as possible, preferably within three days of exposure. There is no vaccine for HIV. When the source of blood is known to be HIV positive, a 3-drug regimen is recommended by the CDC; those exposed to blood with a low viral load or otherwise low risk can use a 2-drug protocol. The antivirals are taken for 4 weeks and can include nucleoside reverse transcriptase inhibitors (NRTIs), nucleotide reverse transcriptase inhibitors (NtRTIs), Non-nucleoside reverse transcriptase inhibitors (NNRTIs), protease inhibitors (PIs), or fusion inhibitors. All of these drugs can have severe side effects. PEP may be discontinued if the source of blood tests HIV-negative. Follow-up of all exposed individuals includes counseling and HIV testing for at least six months after exposure. Such tests are done at baseline, 6 weeks, 12 weeks, and 6 months and longer in specific circumstances, such as co-infection with HCV.

Psychological effects

The psychological effects of occupational needlestick injuries can include health anxiety, anxiety about disclosure or transmission to a sexual partner, trauma-related emotions, and depression. These effects can cause self-destructive behavior or functional impairment in relationships and daily life. This is not mitigated by knowledge about disease transmission or PEP. Though some affected people have worsened anxiety during repeated testing, anxiety and other psychological effects typically abate after testing is complete. A minority of people affected by needlestick injuries may have lasting psychological effects, including post-traumatic stress disorder.

Prevention

A multi-faceted strategy is necessary to prevent needlestick injuries, including proper use of needles, only using needles when necessary, training of people who use needles, improved work practices, and engineering controls. Work practices that reduce the risk of needlestick injuries include using instruments instead of fingers to grasp needles and load scalpels, and avoiding hand-to-hand exchange of sharp instruments. Engineering controls include safety needles, needle removers, retractable needles, needle shields/sheaths, needle-less IV kits, and blunt or valved ends on IV connectors.

Some studies have found that safer needles reduce injuries, but others have shown mixed results or no benefit. The adherence to "no-touch" protocols that eliminate direct contact with needles during use and disposal greatly reduces the risk of needlestick injuries. In the surgical setting, especially in abdominal operations, blunt-tip suture needles were found to reduce needle stick injuries by 69%. Blunt-tip or tapered-tip suture needles can be used to sew muscle and fascia. Though they are more expensive than sharp-tipped needles, this cost is balanced by the reduction in injuries, which are expensive to treat. Sharp-tipped needles cause 51-77% of surgical needlestick injuries. The American College of Surgeons (ACS) and the Food and Drug Administration (FDA) have endorsed the adoption of blunt-tip suture needles for suturing fascia and muscle. Hollow-bore needles pose a greater risk of injury than solid needles, but hollow-bore needle injuries are highly preventable: 25% of hollow-bore needle injuries to healthcare professionals can be prevented by using safer needles. Gloves can also provide better protection against injuries from tapered-tip as opposed to sharp-tipped needles. In addition, the use of two pairs of gloves (double gloving) can halve the risk of needle stick injury in surgical staff. Triple gloving may be more effective than double gloving, but using thicker gloves does not make a difference. However, the evidence is of low quality. A 2014 Cochrane review found low quality evidence showing that safety devices on IV start kits and venipuncture equipment reduce the frequency of needlestick injuries. However, these safety systems can increase the risk of exposure to splashed blood. Education with training for at-risk healthcare workers can reduce their risk of needlestick injuries. The National Institute for Occupational Safety and Health (NIOSH)as a campaign (Stop Sticks) to educate at-risk healthcare workers.

Cost

There are indirect and direct costs associated with needlestick injuries. The US Government Accountability Office (GAO) determined that requiring hospitals to use safety-engineered needles would result in substantial savings due to the reduction in needlestick injuries requiring treatment. Costs of needlestick injuries include prophylaxis, wages and time lost by workers, quality of life, emotional distress, costs associated with drug toxicity, organizational liability, mortality, quality of patient care, and workforce reduction. Testing and follow-up treatment for healthcare workers who experienced a needlestick injury was estimated at $5,000 in the year 2000, depending upon the medical treatment provided. The American Hospital Association found that a case of infection by blood-borne pathogens could cost $1 million for testing, follow-up, and disability payments. An estimated $1 billion annually is saved by preventing needlestick injuries among healthcare workers in the US, including fees associated with testing, laboratory work, counseling, and follow-up costs.

Legislation

In the United States, the Needlestick Safety and Prevention Act of 2000 and the subsequent Bloodborne Pathogens Standard of 2001 require safer needle devices, employee input, and records of all sharps injuries in healthcare settings. In the US, nonsurgical needlestick injuries decreased by 31.6% in the five years following the passage of the Needlestick Safety and Prevention Act. However, this legislation did not affect surgical settings, where injuries increased 6.5% in the same period.

Needle exchange programs

Needle exchange programs were first established in 1981 in Amsterdam as a response from the injecting-drug community to an influx of hepatitis B. Spurred to urgency by the introduction of HIV/AIDS, needle syringe programs quickly became an integral component of public health across the developed world. These programs function by providing facilities in which people who use injecting drugs can receive sterile syringes and injection equipment. Preventing the transmission of blood-borne disease requires sterile syringes and injection equipment for each unique injection, which is necessarily predicated upon access and availability of these materials at no cost for those using them.

Needle exchange programs are an effective way of decreasing the risk associated with needlestick injuries. These programs remove contaminate syringes from the street, reducing the risk of inadvertent transmission of blood-borne infections to the surrounding community and to law enforcement. A study in Hartford, Connecticut found that needlestick injury rates among Hartford police officers decreased after the introduction of a needle exchange program: six injuries in 1,007 drug-related arrests for the 6-month period before vs. two in 1,032 arrests for the 6-month period after.

Data almost universally confirm the value of needle exchange programs, which substantially decrease the risk of HIV among injectable drug users, and do not carry unintended negative consequences. US states that publicly fund exchange programs are associated with reduced rates of HIV transmission, increased availability of sterile syringes among injecting drug users, and increased provision of health and social services to users. States that do not fund needle exchange programs are associated with increased rates of HIV/AIDS.

Nevertheless, the US government has explicitly prohibited federal funding for needle exchange programs since 1988, as part of the zero tolerance drug policy in that country. Needle exchange programs have therefore been sparsely implemented in the United States, where harm reduction is still criminalized.