It has been long recognized in the surgical arena that sterile conditions are important in order to prevent wound infections. Until recently, less emphasis has been placed on the environmental contamination outside of the operating room. In the United States, it has been estimated that hospital-acquired infections (HAIs) kill over 100,000 people each year and cost in excess of 35 billion dollars [1
].This is mortality equivalent as a 300-passenger airliner fatally crashing each day.
It is imperative that all sources of HAIs be identified, addressed and cleaned as well as possible. In every hospital room, there is a patient bed, which is comprised of a bed deck (frame) and a mattress. The mattress consists of different inner workings (e.g., foam or more sophisticated air mattresses) and a permanent cover that is not removed between patients. These permanent covers are most commonly made of polyurethane, nylon, or Gore-tex®
surface. These mattresses must be cleaned between patients, along with the other parts of the patient room. The Centers for Disease Control and Prevention (CDC) recommended in 2003 mattresses be cared for in such a manner to prevent the spread of HAIs. In the 2003 publication on environmental infection control in healthcare facilities, the CDC acknowledged that hospital mattresses can become contaminated during patient care [4
]. They recognized that the linen sheet is not a cover and that mattresses should be replaced when torn, punctured or stained. They recommended that mattresses be cleaned and disinfected between patients using Environmental Protection Agency (EPA)- registered disinfectants that are compatible with the mattress cover materials to prevent tears, cracks and holes in the cover. Finally, the CDC recommend laundering mattress covers that are made of fabric and all pillow covers.
The Centers for Disease Control and Prevention (CDC), in its most recent guideline for disinfection and sterilization in healthcare facilities, considers many areas of the patient room to be “non-critical” and does not make specific recommendations for cleaning standards for these areas [5
]. According to this guideline, bedrails are non-critical surfaces. The mattress and bed deck are not specifically adressed in the new guidelines. Several studies have shown that the entire hospital room, and especially the hospital bed, commonly remains contaminated even after terminal cleaning, the cleaning that occurs after the patient is discharged [6
]. Recent studies have shown that, if the previous occupant had infections with methicillin-resistant Staphylococcus aureus
(MRSA), vancomycin-resistant Enterococcus
(VRE), or Clostridium difficile
, there is a significantly increased risk of the subsequent patient contracting diseases caused by these organisms [10
Several studies have documented the hospital mattress as a vector for HAIs. In England, two different research teams have isolated Pseudomonas aeruginosa
inside mattresses during outbreaks of P. aeruginosa
at their facilities [13
]. Another English hospital cultured MRSA from foam mattresses during an outbreak of MRSA [15
]. In the United States, Canada, and England, antibiotic-resistant strains of Acinetobacter
have been isolated from mattresses during outbreaks of Acinetobacter
in burn units [16
]. One incubator mattress was implicated in an outbreak of neonatal gastroenteritis with Samonellawien
]. There is published evidence that demonstrates enhanced cleaning of the hospital room may help decrease the transmission of infections from the environment [20
In the hospital environment, other than the operating room, the guiding principle for cleaning has been to decrease contamination without any attempt to achieve sterilization. Three authors have proposed levels of bacterial contamination that might be an acceptable standard for assessing terminal cleaning of hospital rooms [24
]. Unfortunately, there is no evidence that these levels of contamination are low enough to help prevent HAIs.
In order to provide the cleanest possible environment for patients, many hospitals have enhanced cleaning efforts in rooms. Curtains are no longer simply cleaned when they are visually soiled; they are replaced after each patient use because research has shown how contaminated curtains can become. Some hospitals are testing the use of ultraviolet lights and hydrogen peroxide as means to more effectively kill bacteria and decrease hospital-acquired infections. However, one area that has not received enough attention is the hospital bed. Of all of the areas in the hospital room, the hospital bed is the object with which patients have the most contact.
Determining the level of bacterial contamination in hospital rooms is critical to developing housekeeping methods to decrease HAIs. The Centers for Medicare and Medicaid Services have recently mandated that hospitals enact an infection prevention and control program that includes “appropriate monitoring of housekeeping…to ensure that the hospital maintains a sanitary environment.” [27
In 2011, Trinity Guardion (Batesville, IN) developed a launderable cover for hospital beds. This cover is engineered to protect the mattress and the bed deck from contamination, and it allows hospitals to launder the cover between patients. There are no published studies evaluating the performance of these covers in the clinical environment.
The current research focuses on the potential ability of these new launderable covers to reduce bacterial contamination of hospital beds. Prior research on bacterial contamination in hospitals has used a number of methods for enumerating bacteria on surfaces. A commonly reported method is to utilize moistened cotton-tip or rayon-tipped swabs [7
]. In recent years several authors have used contact plates, Replicate Organism Detection and Counting (RODAC™) and contact slides (DIPSLIDE™), to detect and enumerate bacteria on environmental surfaces [8
]. Other authors have described using gauze to rub the surface [18
In the food industry, it is common to use Petrifilm™ plates (3M™, St. Paul, MN, USA) to enumerate bacterial counts in food processing plants. These plates are easy to use and do not require the use of a microbiological laboratory. One researcher used the Petrifilm™ Staph Express Plates to detect methicillin-resistant Staphylococcus aureus
(MRSA) on egg-crate mattresses [31
The current research had three goals. The first goal was to evaluate how well terminal cleaning eliminates bacteria from hospital beds (mattresses and bed deck). The second goal was to compare bacterial contamination of beds after terminal cleaning to the contamination on a laundered cover. The third goal was to compare contamination on beds protected by a sheet to those covered with a launderable cover and a sheet.