Needlestick Injuries Among Healthcare Workers

As the Director of the National Institute for Occupational Safety and Health (NIOSH), I thank you, Chairman Ballenger, and members of the Subcommittee, for the opportunity to submit this statement, which discusses the science and public health issues that pertain to needlestick injuries among healthcare workers.

NIOSH is a research institute within the Centers for Disease Control and Prevention (CDC), a part of the Department of Health and Human Services. CDC, through NIOSH, is the federal agency mandated to conduct research to identify and prevent workplace safety and health hazards. In addressing needlestick injuries, NIOSH works closely with the National Centers for Infectious Disease (NCID), also part of CDC.

This statement summarizes the scientific issues related to needlestick injuries, including what we know about the number of workers affected, what can happen to a worker's health as a result of such an injury, how these injuries occur, and ways to prevent them. In addition, it describes what CDC is doing to address this serious public health problem.

First, it is important to provide some context about healthcare workers in general. Over 10 million workers are now employed in healthcare industries. They cover a range of occupations, from nurses and doctors to pharmacists to laboratory technicians to dental assistants. Healthcare services are growing at twice the rate of the overall economy – rivaling the high-tech field – with over three million new jobs projected by 2006.

The Number of Needlestick Injuries
We know that needlestick injuries are contributing to the overall burden of healthcare worker injuries. Although we do not know exactly how many work-related needlesticks occur each year across the country, estimates indicate that 600,000 to 800,000 such injuries occur annually, about half of which go unreported. A recent CDC study estimates that an average of 385,000 needlestick injuries occur annually in U.S. hospital settings. At an average hospital, workers incur approximately 30 reported needlestick injuries per 100 beds per year. Most reported needlestick injuries involve nursing staff; but laboratory staff, physicians, housekeepers, and other healthcare workers are also injured. Healthcare workers outside the hospital setting are also at risk. Others at clinics, private medical and dental offices, nursing homes, correctional facilities, and in the community, such as emergency medical response workers, are also at risk of exposure to contaminated blood.

Needlestick Injuries and the Risk of Disease
Fortunately, most needlestick injuries do not result in exposure to an infectious disease, and of those that do, the majority do not result in the transmission of infection. Nevertheless, needlestick injuries may expose workers to bloodborne pathogens such as human immunodeficiency virus (HIV), hepatitis B virus, and/or hepatitis C virus. A healthcare worker's risk of infection depends on several factors, such as the pathogen involved, the severity of the needlestick injury, and the availability and use of pre-exposure vaccination and post-exposure prophylaxis (i.e., protective treatment for the prevention of disease once exposure has occurred).

HIV
HIV infection is a complex disease that can be associated with many symptoms. The virus attacks part of the body's immune system, eventually leading to severe infections and other complications – a condition known as AIDS. Despite current therapies that delay the progression of HIV disease, many individuals who become infected with HIV are likely to develop AIDS.

As of December 1999, CDC received reports of 56 "documented" cases and 136 "possible" cases of occupationally acquired HIV infection in the U.S. Most involved nurses and laboratory technicians. Percutaneous injury – such as needlesticks – was associated with 89% of the documented occupationally acquired infections. Studies that followed healthcare workers with occupational HIV exposures indicate that the risk of transmission from a single percutaneous exposure, such as a needlestick or a cut with a sharp object, to HIV-infected blood is approximately 0.3%. To say this another way, three of every 1,000 healthcare workers stuck with a needle contaminated with HIV-positive blood will become infected with HIV.

An epidemiologic study of healthcare workers who had percutaneous exposures to HIV found that the risk of HIV transmission was increased in certain circumstances: when the worker was exposed to a larger quantity of blood from the patient, a procedure that involved placing a needle in a patient's vein or artery, a deep injury, or when the patient was in a phase of the illness associated with higher viral levels.

Hepatitis B Virus
Hepatitis B virus (HBV) infection is another risk associated with needlestick injuries. About one-third to one-half of persons with acute HBV infection develop symptoms of hepatitis such as jaundice, fever, nausea, and abdominal pain. Most acute infections resolve, but 2% to 6% of patients develop chronic infection with HBV that carries an estimated 15% lifetime risk of dying from cirrhosis of the liver or from liver cancer.

CDC national hepatitis surveillance indicates that, in 1997, an estimated 500 healthcare workers became infected with HBV. This figure represents a greater than 95% decline from the 17,000 new infections estimated in 1983, largely due to the widespread immunization of healthcare workers with the hepatitis B vaccine and the use of universal precautions.

Most healthcare workers are immune to HBV due to pre-exposure vaccination. However, studies done before the availability of hepatitis B vaccine showed rates of HBV transmission ranging from 6% to 30% after a single needlestick exposure to an HBV-infected patient.

Hepatitis C Virus
Healthcare workers with needlestick injuries are also at risk for infection with the Hepatitis C virus (HCV). The precise number of healthcare workers who have acquired HCV occupationally is not known. However, epidemiologic studies of healthcare workers exposed to HCV through a needlestick or other percutaneous injury have found that the incidence of infection averages 1.8% per injury. Of the total new HCV infections that have occurred annually (declining from 112,000 in 1991 to 38,000 in 1997), 2% to 4% have been in healthcare workers exposed to blood in the workplace.

HCV infection often occurs with no symptoms or only mild symptoms. But unlike HBV, with only 2% to 6% of adults developing chronic infection, with HCV chronic infection develops in 75% to 85% of patients. Seventy percent of those with chronic HCV develop active liver disease, with 10% to 20% of patients then developing cirrhosis and 1% to 5% developing liver cancer over a period of 20 to 30 years.

Prophylaxis and Post-Exposure Treatments
Postexposure prophylaxis is available for hepatitis B and HIV exposures but not for hepatitis C. However, preventing the needlestick injury in the first place is the best approach to preventing these diseases in healthcare workers, and it is an important part of any bloodborne pathogen prevention program in the workplace.

Emotional Impact
Another serious effect of needlestick injuries is the emotional toll on healthcare workers. With each needlestick incident, workers face the possibility of having been exposed to a bloodborne pathogen, in which case they face difficult decisions about undergoing medical treatment with both short-term and long-term side effects. In addition, the worker is advised to use barrier contraception and to postpone decisions on childbearing.

Studies have shown that the emotional impact of a needlestick injury can be severe and long lasting, even when a serious infection is not transmitted. This impact is particularly severe when the injury involves exposure to HIV. In one study of 20 healthcare workers with an HIV exposure, 11 reported acute severe distress, 7 had persistent moderate distress, and 6 quit their jobs as a result of the exposure. Other stress reactions requiring counseling have also been reported. Not knowing the infection status of the source patient can accentuate the healthcare worker's stress. In addition to the exposed healthcare worker, colleagues and family members may suffer emotionally.

How Needlestick Injuries Occur: Devices and Activities
Healthcare workers use many types of needles and other sharp devices to provide patient care.

Whenever one of these "sharps" is exposed in the work environment there is an opportunity for injury. Data from two surveillance programs, the CDC National Surveillance System for Healthcare Personnel (NaSH) and EPINet, a project developed by Dr. Janine Jagger at the University of Virginia, provide descriptive epidemiological evidence of how such injuries occur, including under what circumstances, with what devices and during what types of procedures. The picture that emerges reflects a continuum of risk opportunities throughout the life-cycle of sharp device use involving interactions among patients, workers, devices and the environment. Approximately 38% of percutaneous injuries occur during use, when a needle or other sharp being manipulated in a patient becomes accidentally dislodged. Other injuries occur after use during cleanup, or in association with the disposal of a sharp device.

The circumstances leading to a needlestick injury depend partly on the type and design of the device used. In addition to risks related to device characteristics, needlestick injuries have been related to certain work practices such as recapping, transferring a body fluid between containers, and failing to properly dispose ofused needles in puncture-resistant "sharps" containers.

Preventing Needlestick Injuries
Based on a review of the science, CDC recommends a hierarchical approach for implementing strategic measures to prevent needlestick injuries. Among these measures is eliminating the use of needles wherever possible through changes in how medications are delivered or specimens obtained, and by using engineered technologies, such as non-needle connectors for intravenous delivery systems. If safe and effective alternatives to needles are not available, devices with engineered sharps injury prevention features such as shields and sheaths should be used. In addition to the changes in the use of medical devices, other factors that must be addressed in the prevention of needlestick injuries include modification of hazardous work practices, administrative changes to address needle hazards in the environment (e.g., prompt removal of filled sharps disposal boxes), safety education and awareness, feedback on safety improvements, and action taken on continuing problems. Each healthcare setting should have its own carefully tailored program, developed with front line worker input and review.

Effectiveness of Medical Devices with Safety Features
Research has shown that devices with safety features, especially when used as part of a comprehensive prevention program are effective in preventing needlestick injuries.

For example, some studies have shown that needleless or protected-needle IV systems decreased needlestick injuries related to IV connectors by 62% to 88%. In a CDC study, phlebotomy injuries (i.e., those involving the letting of blood) were reduced by 76% with a self-blunting needle, 66% with a hinged needle shield, and 23% with a sliding-shield, winged-steel (butterfly-type) needle. Another study concluded that phlebotomy injuries were reduced by 82% with a needle shield, but a recapping device had minimal impact. Other research concluded that safer IV catheters that encase the needle after use reduced needlestick injuries related to IV insertion by 83% in three hospitals.

A number of sources have identified the desirable characteristics of safety devices, which can be used as a guideline for device design and selection. These are included, along with a description of their limitations, in CDC's Alert, Preventing Needlestick Injuries in Healthcare Settings (November 1999).

Comprehensive Safety Programs
Although medical safety devices are key in the prevention of needlestick injuries, as already mentioned, they are most effective when used in the context of a comprehensive safety program that considers all aspects of the work environment and that has employee involvement and management commitment. Several studies document substantial reductions in needlestick injuries with the proper use of needleless systems or newer safety needle devices used in a comprehensive program to prevent needlestick injuries.

CDC believes that a comprehensive strategy to prevent percutaneous injuries is necessary and should include the following:

occupational injury and disease surveillance to identify procedures, devices and injury mechanisms for targeting prevention efforts;

development and implementation of a prevention plan that includes 1) elimination of unnecessary use of needles, 2) implementation of devices with safety features, 3) modification of procedures and work practices, 4) healthcare worker education, and 5) safety promotion in the work environment; and

outcome evaluation.

The critical role of appropriate training has been emphasized by several recent reports of increased patient bloodstream infections associated with improper care of needleless IV systems, primarily in the home healthcare setting. These data emphasize the need for patient safety surveillance and thorough training as well as occupational injury surveillance when implementing the use of a new medical device.

One recent study tracked phlebotomy services at a major institution and found that from 1993 to 1996, the needlestick injury rate among its 200 full-time phlebotomists decreased almost 90% (from 1.5 to 0.2 per 10,000 venipunctures performed). The low rate achieved is almost 80% below an estimate of the national rate (0.94 per 10,000 venipunctures). The actions contributing to the success of the phlebotomy services included changes in worker education and work practices, the implementation of devices with safety features, and encouragement of injury reporting. These interventions as well as the implementation of CDC published guidelines and the Occupational Safety and Health Administration's (OSHA) bloodborne pathogens standard were associated with the observed steady decline in the injury rate. The authors also noted that an important factor contributing to this success was a thorough understanding among the institution's staff of the injuries that had occurred.

Another recently published study, funded by CDC, examined needlestick injuries in an acute-care community hospital in Greater Washington, D.C., from 1990 to 1998. The study found that implementation of a multi-faceted intervention program led to a significant and sustained decrease in the overall rate of sharps injuries. Annual sharps injury incidence rates decreased from 82 sharps injuries/1,000 full-time workers to 24 sharps injuries/1,000 full-time workers, representing a 70% decline in incidence rate overall. The hospital's interventions included an intensive training effort, expanded employee health programs, and an expedited injury reporting process with a focus on confidentiality issues, an anti-needlesticks and sharps task force, and the implementation of new work practices, as well as the use of medical safety devices.

CDC Efforts to Address Needlestick Injuries
CDC has had a long-standing interest and involvement in the prevention of needlestick exposures dating back to its 1987 guidelines for universal precautions that included recommendations for the safe handling of sharp devices, including proper disposal. In a 1998 report, CDC reviewed the proper location, use, and benefits of sharps disposal containers, which play a key role in needlestick injuries. Last November, after reviewing the available scientific research, CDC – with a broad range of review from diverse stakeholders – published a national Alert on Preventing Needlestick Injuries in Healthcare Settings (mentioned previously herein and attached hereto), which was distributed to every hospital in the country. The Alert contains public health recommendations for preventing needlestick injuries, as reflected in my previous comments. CDC is now conducting an evaluation of the impact of the Alert.

CDC is currently funding and conducting a wide variety of extramural and intramural projects aimed at reducing the occurrence of needlestick injuries and exposure to bloodborne pathogens. Current research on exposure prevention is focused on the following:

evaluating safer blood collection devices;
developing evaluation criteria for selecting medical devices;
developing benchmarks for needlestick exposure frequencies that could be used for local prevention efforts to protect healthcare personnel;
funding hospitals to demonstrate the use of data-driven strategies for the prevention of needlestick injuries; and
developing a workbook on the prevention of needlestick injuries to guide healthcare organizations in developing, implementing, and evaluating a prevention plan.

An extramural project beginning later this year will work to provide new data on healthcare workers who work outside of hospitals, reflecting the changing environment of healthcare delivery. CDC has also worked on a number of projects with universities to examine safety climate and work organization factors that have an impact on needlestick injuries and to evaluate training programs for healthcare workers.

In terms of postexposure management, CDC is monitoring the use and side effects of postexposure prophylaxis after occupational exposures, assessing immune responses of healthcare personnel, and assessing factors that influence selection of postexposure measures. CDC has also joined the Health Resources and Services Administration in funding the PEPline, an 800 number that provides treatment advice to clinicians treating workers who have been occupationally exposed to blood.

Also of note, coordinated national efforts to address needlestick injuries are occurring through Healthy People 2010, the Department of Health and Human Service's national health promotion and disease prevention initiative (Objective 20-10, Reduce occupational needlestick injuries among healthcare workers to 420,000 annual needlestick exposures) and the National Occupational Research Agenda, or NORA^TM, a national research framework created and implemented by a broad group of stakeholders. Several of NORA's 21 priority research areas, including Infectious Diseases and Intervention Effectiveness Research, are addressing needlestick injury issues.

Areas for Further Research
As with any emerging public health problem, there are several important areas in which our knowledge about needlestick injuries and their prevention can be improved. Because most of the medical devices are in the first generation stage, ongoing review of current devices and options will be necessary. Research will continue to improve the safety features of devices. Evaluation studies to provide improved information on what does and does not work will similarly continue to improve the effectiveness of comprehensive safety programs. Because training for employers and healthcare workers is a vital part of a comprehensive prevention program, especially as new and safer devices are introduced, model training curriculums need to be developed and evaluated at regular intervals.

There is a need to improve national surveillance and to build institutional capacity for measuring the impact of prevention efforts. The two existing systems in the U.S. that collect information on needlestick injuries have certain limitations. CDC's NaSH surveillance system, mentioned earlier, is comprised of 60 hospitals around the country that voluntarily report blood exposures to the CDC. The EPINet system, also mentioned previously, counts needlestick injuries at 84 hospitals. Neither system surveys a random selection of hospitals, and the participating hospitals may not be representative of all hospitals across the U.S. Also, we do not have data available to tell us whether the problem of needlestick injuries is occurring uniformly across the country, or if there are pockets where the situation is worse.

In addition, there is no system in place to track the millions of healthcare workers employed outside of hospitals, or exposed workers who are not healthcare workers. Needlestick injuries at public health sector facilities are also not counted by current reporting requirements. Moreover, from observational studies, we estimate that approximately half of all needlestick injuries are never reported by employees.

Accurately tracking needlestick injuries is critical. Tracking – or public health surveillance – involves a continuous and systematic process of collecting, analyzing, interpreting, and disseminating descriptive information to monitor health problems. Surveillance is used to guide disease prevention and control activities and provides a basis for public health policy. Some have called surveillance the eyes and ears of public health. Without surveillance, we don't know how big a problem is, whether it's getting bigger or smaller, where it is, or whether our attempts at prevention are effective.

Improved surveillance could be used to identify potential risk factors associated with needlestick injuries, such as high-risk occupations, settings, or procedures, and detect the emergence of new problems. We could also use enhanced surveillance systems to track whether interventions put into place significantly help reduce injuries; for example, whether changes in staffing ratios or the use of newer medical safety devices has an impact on these injuries. Individual facilities could use surveillance to identify problem areas and solutions within their own organization and could use the national data as a benchmark for comparison with their own data. Any enhanced surveillance systems would include appropriate privacy and confidentiality protections for those being monitored.

Conclusion
While the science base on needlestick injuries continues to grow, completed research indicates that such injuries are an important and continuing cause of exposure to serious and sometimes fatal infections among healthcare workers. Greater collaborative efforts by all stakeholders are needed to prevent needlestick injuries and the consequences that can result. Such efforts are best accomplished through a comprehensive program that addresses institutional, behavioral, and device-related factors that contribute to the occurrence of needlestick injuries in healthcare workers. Critical to this effort is the elimination of needle use where safe and effective alternatives are available and the continuing development, evaluation, and use of needle devices with safety features. All such approaches must include serious initial and ongoing training efforts. Monitoring systems are also needed to provide accurate information on the magnitude of needlestick injuries and trends over time, potential risk factors, emerging new problems, and the effectiveness of interventions in all healthcare settings.

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