The role of surface disinfection in the transmission of nosocomial infections
The spread of infections through contact is linked to a series of environmental conditions that affect the development and transmission of pathogens. It has been found that many pathogens persist in the surrounding environment, where they remain for days or even months. Although infection transmission (direct or indirect) is most likely to occur through person-to-person contact, the role of surfaces in transmission via contact with contaminated surfaces must not be ignored. Thus, managing environmental hygiene in medical wards plays a crucial role in avoiding the transmission of nosocomial infections.
Hand hygiene has been the primary focus of infection prevention efforts; however, the design and selection of surfaces in the built environment (especially those identified as "high-touch surfaces") are also important considerations for breaking the chain of transmission. In this regard, the regular use of hand and skin disinfectants is essential for medical staff as well as patients and visitors.
High-touch surfaces
High-touch surfaces, which can increase the risk of pathogen transmission, are often considered in the context of the patient room (e.g., bed rails, over-bed tables, door hardware, call systems), but high-touch objects are also found in public areas (e.g., public chairs, elevator buttons, information desks). When selecting finishes for these surfaces, various materials and cleaning products should be thoroughly evaluated based on evidence, the intended application, costs, and the logistics involved to achieve the desired results.
Along with surfaces, it has been found that ambient environmental factors, such as temperature, relative humidity, room ventilation rates, type of ventilation, and pressure differentials relative to adjacent spaces, affect the growth and transmission of microorganisms.
Chain transmission of potentially dangerous microorganisms
As described in an analysis report[1] of 1,022 outbreaks of nosocomial-associated infections, the most common reservoirs of pathogens (viruses, bacteria) were hospital patients, followed by medical equipment or devices, the surrounding environment, and medical staff.
Although infection transmission (direct or indirect) is most likely to occur through person-to-person contact, via air, water, or droplets, the role of surfaces in contact transmission must not be ignored.
Surfaces are generally classified either as hard surfaces (e.g., window sills, stations and workstations, floors, walls, ceilings) or as soft surfaces (e.g., bed linen, upholstery, privacy curtains, clothing).
Several studies have reported that these surfaces are constantly touched by hospital staff during patient care, thus becoming potential reservoirs for microbes and spores. This indirect chain of transmission could include the organism or agent (i.e., a pathogen), a reservoir (e.g., a surface), objects or materials in and around the patient area that can be carriers of infection (i.e., fomites), a susceptible host carrier (e.g., a caregiver's hands), and a susceptible host reservoir (e.g., the patient).
Solutions for preventing the transmission of microorganisms include hand hygiene, physical barriers, touchless systems, private rooms, isolation, surface selection, and cleaning strategies.
Individual surfaces must be evaluated in the context of accessible and applicable cleaning strategies and technologies. KLINOSEPT® – Rapid surface disinfectant
Impact of environmental conditions on the transmission of nosocomial infections
Several studies, which have shown reduced infection rates, have tested the built environment and organizational factors, such as the number of patients in a room, previous room occupancy, and the level of activity. It has been found that environmental factors, such as temperature, relative humidity, and ventilation, affect the growth and transmission of microorganisms.
Although there has been no conclusive research, temperatures between 20 and 25°C, humidity below 68%, and frequent ventilation have led to a decrease in infections. AMBIOCIDE® – Microaeroflora disinfectant
Cleaning and disinfection of hospital surfaces
The benefits of cleaning soiled surfaces have been recognized for over 150 years. Several design factors affecting cleanliness, including room type, configuration, and occupancy, have also been discussed in various studies. In addition to the ambient environmental conditions mentioned earlier, the design and selection of surfaces, materials, and finishes must be considered in light of organizational policies and cleaning and disinfection procedures.
With this in mind, the choice of surface cleaning strategies should be determined by factors such as the nature of the items to be cleaned (e.g., critical, semi-critical, or non-critical surfaces), the quantity of microorganisms present, their potential for resistance, the level of disinfection required (e.g., high, intermediate, low), and any limitations or specifications of the available products. Disinfection solutions in the specialized literature have been broadly classified into three categories:
- Manual cleaning with professional disinfectants
- Automated, touchless disinfection technologies
- Self-disinfecting surfaces
Spraying disinfectants and wiping surfaces with microfiber/cotton cloths are the first stages of the cleaning process. The disinfectant concentration, choice of applicator, application process, volume-to-surface ratio, and total contact time can enhance or undermine surface decontamination. KLINTENSIV DEZICON® – High-level concentrated disinfectant
While regular cleaning is necessary to eliminate pathogens and maintain hygiene, it is not the only mechanism available. Several strategies, such as innovative cleaning technologies and self-disinfecting materials, are extremely useful.
Contrary to cleanliness expectations, studies have shown that less than 50% of hard surfaces are adequately cleaned when chemical germicides are used. Furthermore, studies show that some lesser-known high-touch pathogen reservoirs (e.g., privacy curtains) are not cleaned or disinfected unless they are visibly soiled.
The cleanliness of high-touch surfaces in healthcare environments is usually assessed by visual inspection. But when ATP (adenosine triphosphate) bioluminescence and microbiological examinations (e.g., aerobic colony counts) were used, surfaces that appeared clean did not meet benchmark requirements, and it was found that 90% of the tested surfaces did not meet the necessary standards. In this regard, it is also recommended to disinfect the microaeroflora in hospital wards and treatment areas. The use of a nebulizer and professional disinfectants should complement surface sanitization procedures.
Selecting products for hospital surface disinfection
In Romania, disinfectants, sanitizers, and chemical sterilizers are regulated by the Ministry of Health – National Commission for Biocidal Products. Any substance intended to prevent, destroy, repel, or mitigate the development of microorganisms must be registered and approved by the competent bodies.
For the sanitization and disinfection of hospital surfaces, the following product categories can be used:
