Cleaning and Disinfecting of Surfaces in Hospitals and medical care areas
Infection Control: Surfaces Disinfecting
Infection transmission from surfaces in healthcare areas
Microbiologically contaminated surfaces is a reservoirs for pathogens, which can be transmitted to patients and medical staff via hand contact and/or surfaces of surgical and service instruments.
Hence the importance of cleaning and disinfection protocols in reducing the chance and possibility of infection transmission through these surfaces.
To organize this work, infection control experts have divided the risk of transmission of infection via surfaces and service tools in the medical environment into three categories: “critical, semi-critical, non-critical.”
Rules governing the selection of the appropriate type of disinfection for surfaces
- The nature of the item to be sterilized, the type of manufacturing material and its properties
- The expected bacterial population size on the item.
- Type of bacteria and its expected resistance to disinfectants
- The type of disinfectant used and the duration of direct contact with the contaminated surface.
Disinfection level and effect on Pathogens
In all cases, any disinfection or sterilization process for surfaces or tools must begin with cleaning with running water, because cleaning helps reduce dust, impurities, and the amount of bacterial spread on surfaces, which enhances the efficiency of the disinfection process.
In the case of surfaces, emphasis must be placed on the need to scrub the item well to remove as much bacteria and hardened nodules as possible to enhance the success of the disinfection process.
The process of high-level disinfection, an appropriate standard of treatment for heat-sensitive, semi-critical medical instruments (e.g., flexible, fiberoptic endoscopes), inactivates all vegetative bacteria, mycobacteria, viruses, fungi, and some bacterial spores.
High-level disinfection is accomplished with powerful, sporicidal chemicals (e.g., glutaraldehyde, peracetic acid, and hydrogen peroxide) that are not appropriate for use on housekeeping surfaces. These liquid chemical sterilants/high-level disinfectants are highly toxic.
Use of these chemicals for applications other than those indicated in their label instructions (i.e., as immersion chemicals for treating heat-sensitive medical instruments) is not appropriate.
Intermediate-level disinfection does not necessarily kill bacterial spores, but it does inactivate Mycobacterium tuberculosisvar. bovis, which is substantially more resistant to chemical germicides than ordinary vegetative bacteria, fungi, and medium to small viruses (with or without lipid envelopes).
Chemical germicides with sufficient potency to achieve intermediate-level disinfection include chlorine-containing compounds (e.g., sodium hypochlorite), alcohols, some phenolics, and some iodophors. Low-level disinfection inactivates vegetative bacteria, fungi, enveloped viruses (e.g., human immunodeficiency virus [HIV], and influenza viruses), and some non-enveloped viruses (e.g., adenoviruses).
Low-level disinfectants include quaternary ammonium compounds, some phenolics, and some iodophors. Sanitizers are agents that reduce the numbers of bacterial contaminants to safe levels as judged by public health requirements, and are used in cleaning operations, particularly in food service and dairy applications. Germicidal chemicals that have been approved by FDA as skin antiseptics are not appropriate for use as environmental surface disinfectants.
