Emergency medical systems teams are constantly faced with challenges of preventing infection transmission. The emergence of antimicrobial-resistant microbes (e.g., healthcare-acquired and community-acquired methicillin-resistant Staphylococcus aureus [MRSA], vancomycin-resistant Enterococcus [VRE] and multidrug-resistant Gram-negative bacilli), along with growing concern regarding the spread of Clostridia difficile bacteria are problems facing all healthcare providers. A major challenge for EMS is the broad range of potentially transmissible infections, including the above pathogens and others that may be recognized or unrecognized when transporting patients.
Meeting best practices for cleaning and disinfection of environmental surfaces and patient care equipment constitutes an important factor in preventing the spread of infections. Environmental surfaces and patient care equipment can serve as reservoirs for pathogenic microorganisms, and, without clear written policies and procedures for the care, cleaning and disinfection of transport vehicles and equipment, patients and EMS teams are at increased risk. The most common means of infection transmission occurs when gloved or ungloved hands come in contact with a contaminated surface and/or there is patient contact with contaminated surfaces or medical equipment.1,2
Published studies focusing on transmission to surfaces and medical equipment in healthcare facilities have proven that contamination of the environment has likely contributed to the spread of resistant pathogens (MRSA and VRE).1,2 A nationwide research performed in Europe showed that traditional cleaning and disinfection practices had little effect in removing bacterial contamination (specifically MRSA) in ambulances, thus leaving crews and patients potentially at risk.3
OSHA Bloodborne Pathogen Standard
In December 1991, the Occupational Safety and Health Administration (OSHA) issued a standard titled "Occupational Exposure to Bloodborne Pathogens."4 The OSHA BBP rule applies to all persons occupationally exposed to blood and other potentially infectious materials. One of the requirements under the standard is ensuring that each place of employment be kept clean and sanitary. This involves development and implementation of protocols and procedures addressing work practices for employees that include cleaning schedules and appropriate methods of decontamination and disinfection. All equipment and environmental working surfaces must be cleaned and decontaminated with an appropriate disinfectant after contact with blood and other potentially infectious materials.
While the OSHA standard does not specify the type of disinfectant or procedure, the original compliance document suggested that a germicide used to clean a blood spill must be tuberculocidal to kill the hepatitis B virus (HBV);5 however, in February 1997, OSHA amended its policy and stated that EPA-registered disinfectants that are labeled as effective against HIV and HBV would be considered appropriate disinfectants.6 When bloodborne pathogens other than HBV or HIV are of concern, OSHA continues to require the use of EPA-registered tuberculocidal disinfectants or hypochlorite solution (bleach diluted 1:10 or 1:100 with water).7
Classification Approach to Cleaning and Disinfection
In infection prevention and control practice, cleaning and disinfecting (or sterilization) of reusable equipment is based on a classification system. A critical device is a device or item that enters sterile tissue or the vascular system and therefore should be sterile, i.e. IV catheter. Semi-critical devices are items that come in contact with mucous membranes and require high-level disinfection between uses, i.e., laryngoscope blades, oxygen masks, resuscitation bags.
Today, critical devices like IV catheters, needles and syringes are single use and disposable; however, reusable surgical instruments and other critical items that require sterilization and reusable semi-critical items must be reprocessed before use on another person. Many transport systems are not equipped for performing reprocessing of equipment; therefore, arrangements need to be made with hospitals for reprocessing critical and semi-critical devices.
Noncritical items are those that come in contact with intact skin but not mucous membranes. Noncritical items can be divided into noncritical patient care items, such as stethoscopes and blood pressure cuffs, and noncritical environmental surfaces like stretchers, backboards, two-way radios, shelves and door handles in transport vehicles. Noncritical items or surfaces can potentially contribute to secondary transmission of pathogenic microorganisms by contaminated hands or gloved hands, or contact with medical equipment that will subsequently come in contact with patients. Therefore, noncritical items that may be at higher risk of contamination and transmission should be cleaned and disinfected after patient use. Cleaning and disinfection of equipment should be performed at the receiving medical facility as much as possible.
General Principles for Cleaning and Disinfecting
Before one can understand the general principles for cleaning and disinfection, it is important to understand some key definitions. Cleaning is the first step and involves the physical removal of dust, soil and organic material from a surface before disinfection can take place. The use of friction is necessary to remove visible soil, debris and organic material. Decontamination is the process of removing disease-producing organisms to render an item safe for handling. An example of decontamination is placing instruments in a washer-sterilizer or pre-cleaning with an enzymatic detergent solution prior to preparing these critical items for sterilization.
Disinfection is defined as using an agent that destroys or inactivates nearly all disease-producing microorganisms, except for bacterial spores, which are primarily killed by sterilization or high- level disinfection. Environmental surfaces and patient care items are considered noncritical and therefore a low-level or intermediate-level surface disinfectant is recommended.7
New disinfectant products, such as pre-moistened disinfectant wipes, make surface cleaning and disinfection an easy, one-step process that is acceptable for high-touched items that are not visibly soiled, such as stethoscopes, BP cuffs, monitors and stretchers. It is important to note, however, that for items that are visibly soiled with blood or body fluids, one wipe must be used first to clean and remove the visible soil, then use a second wipe to achieve disinfection.
One of the biggest challenges is assigning who is responsible for carrying out cleaning and disinfecting protocols and understanding proper procedures. Transport personnel are frequently unaware of responsibilities and specific cleaning protocols, therefore it is critical that protocols and routines for cleaning surfaces and medical equipment be established and posted. These protocols should list all items to be cleaned and disinfected, frequency for performing the task (e.g., after patient use or daily), product to use for cleaning/disinfecting, how to clean/disinfect the item (if applicable) and person(s) responsible for performing these tasks.
Per the OSHA BBP Standard, compliance monitoring and evaluation of cleaning and disinfection and safe work practices should be conducted on a regular basis by transport team leadership, management or designated persons. All employees and volunteers should receive feedback on monitoring activities and education in disinfection protocols and safe work practices on an annual basis and as needed.
Selecting the Right Disinfectant
The Environmental Protection Agency (EPA) registers all disinfectants based upon submitted efficacy data by manufacturers and sets specific guidelines for efficacy testing and label requirements. Manufacturers of disinfectants are required to follow EPA regulations for product acceptance. Per OSHA BBP regulations and CDC Guidelines,8 healthcare providers must use EPA-registered disinfectants in accordance with the manufacturer's recommendations. When choosing a disinfectant, look for the EPA registration number on the label and choose one approved by EPA as a hospital-grade disinfectant. A surface disinfectant labeled "tuberculocidal" is an intermediate-level disinfectant; low-level disinfectants do not claim to be tuberculocidal.
Rutala's "APIC Guideline for Selection and Use of Disinfectants" from the Association for Professionals in Infection Control and Epidemiology describes a hierarchy of resistance of microbial categories to germicidal chemicals (see Figure 1).9
The hierarchy of resistance is considered a rough guide to general susceptibility of microorganisms to disinfectants. In descending order, bacterial spores show highest resistance to germicidal chemicals and are the hardest to kill; lipid viruses show the least resistance to germicidal chemicals and are the easiest to kill. Bacterial spores require sterilization or high-level disinfection. Sterilization is the complete elimination or destruction of all forms of microbial life, and high-level disinfection can be expected to destroy all microorganisms, with the exception of high numbers of bacterial spores. Intermediate-level disinfection inactivates Mycobacterium tuberculosis, vegetative bacteria, viruses and fungi, but not spores. Low-level disinfection can kill most bacteria, some viruses and some fungi, but not mycobacteria.
Because choosing the appropriate surface disinfectant can be confusing, it is critical to look at both label claims and technical data sheets for disinfectant efficacy and safety data. Technical data sheets will list microorganisms that include bacteria, viruses and fungi that achieved efficacy testing and the kill times for each microorganism. Product labels will indicate key bacteria, all viruses and fungal organisms tested, active ingredients, directions for use, cautions and precautionary statements. Labels will also indicate overall contact time for the disinfectant. Contact time is the time the disinfectant solution must remain wet on the surface to achieve efficacy against microorganisms.
Always consider pathogens of significance for infection transmission when selecting surface disinfectants. For example, most EPA-registered quaternary ammonium-based products are effective against pathogens of concern today, e.g., Gram-positive (Staphylococcus aureus, MRSA); Gram-negative (E coli, Pseudomonas aeruginosa) microorganisms and most viruses (HIV, HBV, influenza). Clostridia difficile, or C. difficile, a spore-forming bacteria, is emerging as a pathogen of concern for environmental spread. C. difficile spores can only be killed by sterilization or high-level disinfection. Studies have shown that enhanced environmental cleaning with sodium hypochlorite (bleach) at 1:10 dilution can reduce the incidence of transmission.7,8 Bleach prevents the spores from replicating. Manufacturers of surface disinfectants have made claims for killing C. difficile in its vegetative state (the state before spores are formed); however, this information can be misleading, since it is not known how long the bacteria stays in its vegetative state, and the EPA has required that manufacturers remove such claims from their product labels.
Currently, there are no EPA-registered, intermediate-level surface disinfectants approved for killing C. difficile spores. The use of bleach continues to be recommended for patients with C. difficile-associated diarrhea or colitis, or patient units in hospitals and nursing homes with high rates of disease.7,8
When transporting patients who are known to have C. difficile, but have no evidence of active diarrhea, meticulous cleaning with an EPA-registered disinfectant and good hand hygiene should be effective in preventing the spread of the organism.7
In choosing a disinfectant for noncritical surfaces and patient care equipment, always consider the type of item/surface to be cleaned. For example, caution should be taken when using a spray cleaner on surfaces with nooks and crannies when liquid could enter the inside of the device. Disinfectants that are ready to use or dispensed in premeasured amounts are preferred over those that require mixing, as they can eliminate the possibility of human errors in mixing. Always dispense the solution in the safest, most efficient way. Aerosols and sprays must be used with caution, especially around individuals with a history of breathing problems.
Consider ease of use. Does application of the disinfectant consistently provide the correct concentrations to assure proper strength of solution? Busy EMS providers need a product they can access at the point of use. Keeping a disinfectant inside the transport vehicle facilitates compliance with cleaning and disinfection protocols. Premoistened germicidal wipes are ideal for this purpose, since they can be placed at the point of use, require no mixing or need for cleaning cloths or paper towels, and provide the right amount of solution to kill microbes and friction to remove soil from the surface.
Conclusion: Now is the Time to Evaluate Practices
Disinfection of noncritical patient care equipment and environmental surfaces should be included as part of EMS Standard Operating Procedures (SOP) manuals. Ambulances are the front line of medical care, and the risk of exposure to patients with known or unknown infectious diseases or pathogens is high. The importance of understanding the principles of infection prevention and control and reducing disease transmission in EMS is often misunderstood and can lead to error or unsafe practice. Routine cleaning and disinfection and following safe practices are often overlooked or not performed simply because "we don't have time" or it is not recognized as being necessary. When dealing with problem emerging pathogens, the key measures for prevention and management are to focus on following strict cleaning and disinfecting practices, hand hygiene and appropriate use of personal protective equipment. Now is the time to evaluate your practices.
(1) Muto CA, Jernigan JA, et.al. SHEA guideline for preventing nosocomial transmission of multidrug-resistant strains of Staphylococcus aureus and Enterococcus. ICHE 24: 362-386, 2003.
(2) Zachary K et.al. Contamination of gowns, gloves, and stethoscopes with Vancomycin-resistant Enterococcus. ICHE 22: 560-564, 2001.
(4) Occupational Safety and Health Administration, Occupational exposure to bloodborne pathogens; final rule (OSHA 29 CFR 1910.1030). Federal Register 1991; 56: 64003-182. [memorandum] February 28, 1997; compliance document [CPL] 2-2.44D [11/99].
(5) Occupational Safety and Health Administration. OSHA instruction CPL 2-2.44C. Office of Health Compliance Assistance. Washington, DC, 1992.
(6) Occupational Safety and Health Administration. OSHA Memorandum from Stephen Mallinger. EPA-registered disinfectants for HIV/HBV. Washington, DC, 1997.
(7) Rutala W. Disinfection, Sterilization and Antisepsis: Principles, Practices, Current Issues, and New Research. Conference proceedings, Tampa, Florida, June 10, 2006. Association for Professionals in Infection Control and Epidemiology (APIC) pp 30, 31.
(8) Sehulster L, Chinn R. "Guidelines for Environmental Infection Control in Health-Care Facilities: Recommendations of CDC and the Healthcare Infection Control Practices Advisory Committee (HICPAC). MMWR, June 6, 2003 /52(RR10); 1-42.
(9) Rutala W. APIC Guideline for selection and use of disinfectants. Association for Professionals in Infection Control and Epidemiology. Am J Infect Cont 24(4): 313-342, 1996.
Jean Fleming, RN, MPM, CIC is clinical director of Infection Prevention and Education for
Professional Disposables International, Inc.