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Needlestick Injuries Among Healthcare Workers
Linda Rosenstock, M.D., M.P.H.
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
Injuries and the Risk of Disease
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.
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.
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.
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.
Injuries Occur: Devices and Activities
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.
Medical Devices with Safety Features
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).
CDC believes that a comprehensive strategy to prevent percutaneous injuries is necessary and should include the following:
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 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:
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 NORATM, 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.
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.