Know the facts. Know which devices and activities are associated with needle stick injuries. Understand the extent of the problem by learning the statistics on HIV, HCV, and HBV infections contracted via needle sticks. Learn the desirable characteristics of devices with safety features.
Devices Associated with Needle Stick Injuries
Health care workers use many types of needles and other sharp devices to provide patient care. However, data from hospitals participating in the CDC National Surveillance System for Hospital Health Care Workers (NaSH) and from hospitals included in the EPINet research database show that only a few needles and other sharp devices are associated with the majority of injuries.
Of nearly 5,000 percutaneous injuries reported by hospitals participating in NaSH between June 1995 and July 1999, 62% were associated with hollow-bore needles—primarily hypodermic needles attached to disposable syringes (29%) and winged-steel (butterfly-type) needles (13%).
Activities Associated with Needle Stick Injuries
Whenever a needle or other sharp device is exposed, injuries can occur. Data from NaSH show that approximately 38% of percutaneous injuries occur during use and 42% occur after use and before disposal.
The circumstances leading to a needle stick injury depend partly on the type and design of the device used. For example, needle devices that must be taken apart or manipulated after use (e.g., prefilled cartridge syringes and phlebotomy needle/vacuum tube assemblies) are an obvious hazard and have been associated with increased injury rates.
In addition, needles attached to a length of flexible tubing (e.g., winged-steel needles and needles attached to IV tubing) are sometimes difficult to place in sharps containers and thus present another injury hazard.
Injuries involving needles attached to IV tubing may occur when a health care worker inserts or withdraws a needle from an IV port or tries to temporarily remove the needle stick hazard by inserting the needle into a drip chamber, IV port or bag, or even bedding.
In addition to risks related to device characteristics, needle stick injuries have been related to certain work practices such as recapping, transferring a body fluid between containers, and failing to properly dispose of used needles in puncture-resistant sharps containers.
Past studies of needle stick injuries have shown that 10% to 25% occurred when recapping a used. Although recapping by hand has been discouraged for some time and is prohibited under the OSHA blood borne pathogens standard, unless no alternative exists, 5% of needle stick injuries in NaSH hospitals are still related to this practice.
Injury may occur when a health care worker attempts to transfer blood or other body fluids from a syringe to a specimen container (such as a vacuum tube) and misses the target.
If used needles or other sharps are left in the work area or are discarded in a sharps container that is not puncture resistant, a needle stick injury may result.
Statistics on HIV, HBV, and HCV Infections Contracted via Needle Sticks
Between 1985 and June 1999, cumulative totals of 55 documented cases and 136 possible cases of occupational HIV transmission to U.S. health care workers were reported to the Centers for Disease Control and Prevention (CDC).
Most involved nurses and laboratory technicians. Percutaneous injury (e.g., needle stick) was associated with 49 (89%) of the documented transmissions. Of these, 44 involved hollow-bore needles, most of which were used for blood collection or insertion of an IV catheter. 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, most health care workers who become infected with HIV are likely to eventually develop AIDS and die.
Information from national hepatitis surveillance is used to estimate the number of HBV infections in health care workers.
In 1995, an estimated 800 health care workers became infected with HBV [CDC unpublished data]. This figure represented a 95% decline from the 17,000 new infections estimated in 1983. The decline was largely due to the widespread immunization of health care workers with the hepatitis B vaccine and the use of universal precautions and other measures required by the Occupational Safety and Health Administration (OSHA) blood borne pathogens standard.
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 5% to 10% of patients develop chronic infection with HBV that carries an estimated 20% lifetime risk of dying from cirrhosis and 6% risk of dying from liver cancer.
Hepatitis C virus infection is the most common chronic blood borne infection in the United States, affecting approximately 4 million people [CDC 1998b]. Although the prevalence of HCV infection among health care workers is similar to that in the general population (1% to 2%) [CDC 1998b], health care workers clearly have an increased occupational risk for HCV infection.
In a study that evaluated risk factors for infection, a history of unintentional needle stick injury was independently associated with HCV infection. The number of health care workers who have acquired HCV occupationally is not known. However, of the total acute HCV infections that have occurred annually (ranging from 100,000 in 1991 to 36,000 in 1996), 2% to 4% have been in health care workers exposed to blood in the workplace.
HCV infection often occurs with no symptoms or only mild symptoms. But unlike HBV, chronic infection develops in 75% to 85% of patients, with active liver disease developing in 70%. Of the patients with active liver disease, 10% to 20% develop cirrhosis, and 1% to 5% develop liver cancer [CDC 1998b].
Desirable Characteristics of Devices with Safety Features:
- The safety feature is an integral part of the device.
- The user can easily tell whether the safety feature is activated.
- The safety feature cannot be deactivated and remains protective through disposal.
- The device performs reliably.
- The device is easy to use and practical.
- The device is safe and effective for patient care.
Although each of these characteristics is desirable, some are not feasible, applicable or available for certain health care situations. For example, needles will always be necessary where alternatives for skin penetration are not available. Also, a safety feature that requires activation by the user might be preferable to one that is passive in some cases. Each device must be considered on its own merit and ultimately on its ability to reduce workplace injuries. The desirable characteristics listed here should thus serve only as a guideline for device design and selection.