Handwashing is the most important procedure to reduce the duration of exposure to an infectious agent or chemical, to prevent dissemination of an infectious agent, and to reduce overall infection rates in a health care facility. Hand contamination occurs during manipulation of specimens and during contact with work surfaces, telephones, and equipment. Laboratory personnel should wash their hands immediately after removing gloves, after obvious contamination, after completion of work, before leaving the laboratory, and before hand contact with nonintact skin, eyes, or mucous membranes (8).
Handwashing sinks should be located at each entry/exit door; if possible, the faucet should be operated by a knee/foot control. If these controls are not available, the faucet should be turned on and off using a paper towel. Handwashing should be performed using soap or an antiseptic compound, starting at the wrist area and extending down between the fingers and around and under the fingernails, and rinsed from the wrists downward. Recently, the Centers for Disease Control and Prevention recommended that in addition to traditional soap and water handwashing, health care personnel can use alcohol-based gels (8).
Personal Protective Equipment (OSHA 2001 Blood Borne)
Occupational Safety and Health Administration (OSHA) standards for exposure to blood-borne pathogens require the laboratory to provide personal protective equipment (PPE) for its employees. OSHA standards require that PPE be provided, used, and maintained for all hazards found in the workplace, including biological, environmental, and chemical hazards, radioactive compounds, and mechanical irritants capable of causing injury or illness through absorption, inhalation, or physical contact. Employees must be trained in the appropriate use of PPE for a specific task, the limitations of PPE, and procedures for maintaining, storing, and disposing of PPE.
Gloves
Gloves protect the wearer from exposure to potentially infectious material and other hazardous material and are available in material designed for specific tasks. Gloves must be provided by the employer and must be the proper size and appropriate material for the task. Due to latex hypersensitivity in some workers, only powder-free latex gloves should be used or gloves should be manufactured from nitrile, polyethylene, or other material.
Protective Clothing
Laboratory workers should wear long-sleeved coats or gowns that extend below the level of the workbench, and they should be worn fully closed. The material must be fluid resistant if there is any potential for splashing or spraying. Fluid-proof clothing (plastic or plastic lined) must be worn when there is the potential for soaking by infectious material. Laboratory workers should not wear laboratory clothing outside the laboratory. All protective clothing should be changed immediately when contaminated to prevent the potentially infectious material or chemical from contacting the skin. Coats and gowns should not be taken home for cleaning but should be laundered by the institution.
Face and Eye Protection
Face and eye protection should be used when splashes or sprays of infectious material or chemicals may occur. Equipment includes goggles, face shields, and splashguards. Face shields provide the best protection for the entire face and neck, although splashguards provide an alternative method. If only goggles are worn, the user should also wear an appropriate mask to prevent contamination of mucous membranes.
1. Specimens with gross internal contamination must not be accepted. Place the specimen in a plastic bag to protect subsequent handlers. The test request slips should be bagged separately from the specimen (keep paperwork clean and uncontaminated). Wear gloves when handling the specimen, and wash your hands thoroughly when you finish handling the specimen. Notify the supervisor immediately about a contaminated specimen so that further corrective action may be taken.
2. Specimens to be centrifuged must be placed in a sealed container to prevent aerosols.
3. All specimens other than bacterial or fungal blood culture bottles to be set up for isolation of organisms must be processed in a BSC. All “open-system” work is to be done on an absorbent surface (i.e., a towel) in a BSC, using appropriate protective techniques. Towels should be changed daily. We recommend that the immediate working area of the towel be dampened with any recommended disinfectant to handle small spills (Fig. 11.3).
Figure 11.3 Example of a commercially available disinfectant (Solucide) that can be used for countertops, small spills, and any hard surface that requires a disinfectant (www.med-chem.com). doi:10.1128/9781555819002.ch11.f3
1. All specimens are potentially pathogenic—always use careful techniques (Tables 11.3 and 11.4).
2. All discard material used in processing of specimens is considered contaminated.
A. Fluids used in the processing of specimens (buffers, etc.), as well as excess liquid specimens, should be poured into plastic screw-top autoclavable bottles and sterilized prior to disposal. A tongue depressor placed in the bottle can help to prevent splashing if liquid is poured down the slanting stick. These sticks can also be placed in disinfectant before being discarded. Disinfectants and incineration can also be used for decontamination of infectious materials.
B. Reusable items (tissue grinders, bottles, etc.) are placed in an autoclave pan. Once the pan is full, place it (without a cover) in a large brown autoclave bag and staple shut. After being autoclaved, the reusable items can be cleaned.
C. Specimen containers and centrifuge tubes are disposable. These items should be placed in plastic autoclave bags and secured with masking tape for sterilization. Slides can also be placed in containers of liquid disinfectant prior to disposal. Remember, slides should be treated as sharps.
D. Pipettes can be placed in a covered discard pan containing 5% amphyl or placed in autoclavable containers for sterilization before discarding.
1. Disinfectants in use at present
A. Bleach solutions. To be an effective disinfectant, working bleach solutions must contain >0.5% but <2% sodium hypochlorite. Hypochlorite concentration in household bleach varies by manufacturer. Many household bleach solutions contain 5.25% sodium hypochlorite, and a 1:10 dilution (5,000
