Using Germicides for Pathogen Eradication


It pays to pick your strategy and your weapon in the war against healthcare-acquired infections (HAIs). No battleground is tougher than that when facing Clostridium difficile or other multidrug-resistant organisms (MDROs). Rigorous environmental hygiene and the proper use of hospital-grade germicides and sporicides are essential to the eradication of these pathogens.

As the Guide to the Elimination of Clostridium difficile in Healthcare Settings (APIC, 2008) emphasizes, "The environment must be recognized as a critical source of contamination, and it plays a significant role in supporting the spread of infection. Because C. difficile is shed in feces, any surface, item, or medical device that becomes contaminated with feces can act as a source for the spores and, therefore, be involved in infection transmission."

It is critical to understand the immense persistence of C. diff spores in the environment; several studies found that C. difficile spores can remain on hard surfaces for as long as five months. High-touch surfaces in the patient room -- including bedrails, over-bed tables, call buttons, television remote controls, telephones, blood pressure cuffs, flow-control devices for IVs and tube feedings, and commodes -- can be heavily contaminated with spores; in one study, spores were found in 49 percent of the rooms occupied by patients with Clostridium difficile infection (CDI) and 29 percent of the time in rooms of asymptomatic carriers. (APIC, 2008)

When it comes to disinfectants, caution must be used so that sporulation, or the transformation of the organism from the vegetative state to the protected spore state, does not occur. As the Guide to the Elimination of Clostridium difficile in Healthcare Settings (APIC, 2008) explains, "The term 'hypersporulation' has been used to denote the propensity of the bacterium to move from the vegetative form to the spore form with increased rapidity. The term has also been used to note that contact with some germicides stress the bacterium, so it more readily transitions to the spore form. Therefore, the term hypersporulation may be understood as the propensity of the organism to more readily move from the vegetative form to the spore than occurs under usual conditions. Although many EPA-registered germicides kill the vegetative C. difficile, only chlorine-based disinfectants and high-concentration, vaporized hydrogen peroxide kill spores."

Pathogen eradication starts with common-sense cleaning and disinfection practices as outlined in the Centers for Disease Control and Prevention (CDC)'s Guidelines for Environmental Infection Control in Health-Care Facilities. The guidance document says that disinfectants that have been registered with the Environmental Protection Agency (EPA) can be used for routine cleaning in the healthcare environment, and that the act of proper surface and object cleaning is critical for optimal disinfection to then occur.

For Clostridium difficile, the CDC recommends that a sodium hypochlorite solution (bleach) be used in outbreak situations, and that regular surface cleaning and disinfection activities, using the physical motions of cleaning and use of the routine germicide that removes and dilutes spore concentration, are acceptable in the absence of an outbreak. (APIC, 2008) The Guide to the Elimination of Clostridium difficile in Healthcare Settings (APIC, 2008) says, "As the CDC environmental guideline indicates, hypochlorite-based disinfectants have been used with some success for environmental surface disinfection in those patient-care areas where surveillance and epidemiology indicate ongoing transmission of C. difficile. The use of a 10 percent sodium hypochlorite solution mixed fresh daily (one part household chlorine bleach mixed with nine parts tap water) has been associated with a reduction in CDI in some settings."

If using a 10 percent sodium hypochlorite solution, remember these key points (APIC, 2008):

-- Commercially available solutions contain a detergent base, which is helpful in cleaning as well as disinfecting.

-- Evaluate the use of commercially available solutions within your facility. Some hypochlorite products are available in a ready-to-use solution. This may be a time-saving process that minimizes dilution error, but it may also be a challenge for storage and prove to be more costly.

-- Making a mixture of bleach and water will provide only the disinfectant, not the detergent base. Therefore, a two-step process may be needed if cleaning is to be performed prior to disinfection.

-- If a bleach and water mixture is made, use only chlorine bleach without the scent additive, as this reduces the resultant parts per million (ppm) of available chlorine.

-- A bleach and water solution should provide at least 4,800 ppm of available chlorine.

-- There is a difference between a germicidal bleach (6.15 percent hypochlorite), a laundry bleach (6.0 percent hypochlorite), and a discounted bleach (5.25 percent or less hypochlorite).

-- A contact time of one minute for the hypochlorite (bleach and water) solution should provide adequate disinfection for non-porous surfaces. This is accomplished by a thorough wetting of the surface with the hypochlorite solution, then allowing it to air dry.

Providing for the appropriate disinfectant contact time, which refers to the amount of time necessary for the germicide to come into contact with the organism and result in a significant reduction in the number of microorganisms, is a critical step in the disinfection protocol. A 3-logarithmic reduction in the number of organisms is the kill claim that manufacturers must submit to the EPA in order for a germicide to receive approval as acceptable for use in the healthcare environment.

As the Guide to the Elimination of Clostridium difficile in Healthcare Settings (APIC, 2008) explains, "When applying the concept of contact time in the healthcare environment, it is vital for the infection preventionist to know the contact time of the selected germicide and how to apply this knowledge. Germicides commonly used in the healthcare setting have a contact time of 10 minutes, although some have a shorter contact time. This means that the surface being disinfected should come into contact with the germicide (stay wet after cleaning) for 10 minutes (or less according to the specifics of the germicide) in order to reduce the amount of organisms by 3 logs (99 percent). This can best be accomplished by using the bucket method of cleaning, where the germicide is mixed with the appropriate amount of water in accordance with manufacturers recommendations and placed in a clean bucket or container. A clean cloth is used during cleaning, and the cleaning process prohibits the dirty cloth from returning to the bucket or container of clean germicide. The germicide solution must be changed periodically to ensure its effectiveness, and buckets or containers are washed and disinfected regularly, in addition to being inspected for cracks. The practices used during cleaning and disinfection should be clearly outlined in policy format and observation used to evaluate adherence. Germicidal wipes have become an important addition to environmental cleaning, but they must be used appropriately to be effective. Wipes are made of a material, or substrate, that lets them absorb the germicide in which they are packaged and allows that germicide to be distributed onto the surface during the cleaning and disinfection process."

Reference: Association for Professionals in Infection Control and Epidemiology (APIC). Guide to the Elimination of Clostridium difficile in Healthcare Settings. 2008.

Addressing the Challenges of Germicide Use

The proper use of germicides is critical to ensuring their effectiveness in environmental cleaning, as well as protecting healthcare workers and patients. ICT asked a member of industry to tackle challenges relating to germicide usage. The following is a Q&A from experts at Alcavis HDC, LLC:

Q: What have been some of the experiences facilities are having in terms of accidental occupational exposures relating to germicide usage? How can these be prevented?

A: Housekeeping staff have a relatively high-risk job within medical institutions. Not only are they the first line point people tasked with cleaning and disinfecting contaminated surfaces, they face the risk of untoward effects from the cleaning products used daily to combat pathogens if not used correctly or an adverse event occurs during use. Exposure to hazardous cleaning chemicals found and used in the laundry or housekeeping process include the following scenarios:

-- Soaps and detergents may cause allergic reactions and dermatitis.

-- Broken skin from soap or detergent irritation may provide an avenue for infection or injury if exposed to chemical or biological hazards.

-- Mixing cleaning solutions that contain ammonia and chlorine will form a deadly gas.

Avoidance of contact to blood or other potentially infectious materials requires a joint commitment from the manufacturer and employer following guidelines from the Occupational Safety and Health Administration (OSHA). The driver to a successful, event-free process starts the implementation of a facility-written program that meets the requirements of the Hazard Communication Standard (HCS) providing staff training, warning labels and access and familiarity to the material safety data sheet (MSDS).

Q: Chemicals such as bleach, etc. require careful handling, so what are some of the best practices relating to proper handling that you can suggest to environmental services personnel?

A: For all the benefits chlorine has, it is not without its caveats. Bleach, at full and stronger dilutions can cause respiratory, skin, stomach and ear, nose and mouth symptoms. However, exposure to household bleach rarely causes caustic injury. (Rutala) Most hospitals have in place, detailed handling instructions when using bleach inclusive of proper personal protection equipment (PPE), specific dilution processes and disposal mechanisms. New pre-diluted EPA cleared bleach wipes are available that eliminate the need to mix concentrated bleach. In addition, the wipes are used as needed, where as large volumes of bleach mixture must be made daily and many times the excess is discarded down the drain. Finally, wipes have a shelf life of at least 12 months, reducing the concern of efficacy of the mixture.

Q: What are the appropriate personal protective equipment (PPE)-related considerations to keep in mind when handling germicides?

A: For sodium hypochlorite at full strength and stronger dilutions (>5000ppm) eye protection, gloves and clothing protection should be used. The CDC recommends that chlorine solutions used in environmental disinfection be prepared fresh daily due to instability. This practice can pose a risk to the environmental service workers, as the dilution procedure often requires open jugs of bleach poured into wide-mouthed receptacles, or dispensing from full strength bottles into narrow opening spray bottles. A viable alternative is the Alcavis Bleach Wipe. This is a 1:10 dilution of sodium hypochlorite and purified water that is prepackaged in a saturated towelette that can cover a 9-square-foot surface area. By limiting the risk associated with dilution, this product provides a safe, stable and effective means to clean hard surfaces. As stated, the instability of producing diluted bleach on-site puts all contaminated surfaces at risk of being optimally disinfected. Staff respiratory sensitivity can be avoided by using a ready-prepared product. Single-use wipes enhance compliance with environmental cleaning by providing the correct dilution every time and avoiding premature degradation of expensive medical equipment. Of even greater importance, the use of a sodium hypochlorite-based wipe complies with the CDCs recommendation to use bleach for disinfection of the toughest pathogens.

Q: Whats the long-term solution for facilities looking for a way to address problematic pathogens such as Clostridium difficile, yet being mindful of healthcare worker and patient safety?

A: For a resistant organisms such as Clostridium difficile, rotovirus and norovirus, a 1:10 or 1:50 dilution of sodium hypochlorite is required for the routine environmental disinfection of rooms of patients when there is a continued transmission. Chlorine bleach is registered by the EPA for use as a hospital disinfectant because it is a proven, effective and inexpensive product. The Environmental Protection Agency (EPA) has recently required companies to remove products claims of C. diff kill if there is no science based evidence and EPA registration has not been granted. Bleach at a 1:10 dilution is acknowledged by the Centers for Disease Control and Prevention (CDC) for its sporicidal properties. (Guidelines for Isolation Precautions: Preventing Transmission of Infectious Agents in Healthcare Settings 2007). The use of a self-contained bleach package, greatly decreases the risk of any dangers to healthcare and environmental service workers and patients, while providing stellar germicidal results. Of note, sodium hypochlorite production is simple and sustainable; it begins and ends with sodium chloride (common table salt), and water.

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