Colonization of Hospital Curtains by Healthcare-Associated Pathogens
Introduction
Healthcare-associated infections are a serious health problem in hospitals worldwide, and efforts have been made to identify their causes and associated risk factors. Several articles have noted that contamination of different surfaces plays a very important role in the cross-transmission of healthcare-associated pathogens (1–6). Recent studies have reported vancomycin-resistant Enterococcus faecium and methicillin-resistant Staphylococcus aureus on healthcare workers’ hands after contact with contaminated surfaces in patients’ rooms (2). Other studies have shown that nurses become contaminated with methicillin-resistant S. aureus after contact with patients colonized by this organism (3). Similar findings have been reported in intensive care units, demonstrating not only that these fomites contribute to pathogen transmission but also that environmental decontamination is useful for reducing its incidence (4,7,8). Hospital curtains surrounding patients’ beds to provide privacy in shared rooms can become a source of healthcare-associated pathogen transmission for several reasons: patients and healthcare workers handle them frequently; they are changed or cleaned only when visibly soiled or damaged; and healthcare workers do not usually identify curtains as an inanimate source of infection (2). Although recent studies in hospitals around the world have demonstrated contamination of hospital curtains with methicillin-resistant S. aureus, vancomycin-resistant E. faecium, and A. baumannii (9,10,12), awareness of this problem remains limited in Colombia, and curtains made from various materials continue to be used without considering the potential risk when proper cleaning is not standardized. This study sought to identify the bacteria colonizing curtains at a tertiary-care clinic in Medellín and determine whether they represent an unrecognized risk factor and source of hospital infection in this setting.
Materials and Methods
A descriptive, prospective study was conducted at a tertiary-care clinic in Medellín with 100 inpatient beds, an intermediate care unit, an intensive care unit, and a 26-bed emergency and transition area.
The clinic was divided into five critical areas where curtains are used to protect patient privacy: emergency care, transition care (temporary hospitalization while patients are transferred from emergency care to inpatient floors), the second floor (the only floor with shared rooms), the intensive care unit, and the intermediate care unit. Cultures were then obtained from 90 curtains—all curtains in the institution—which were made exclusively of polyester and distributed among the five areas. The curtains were scheduled for washing every eight days, or earlier only when visibly soiled or contaminated with bodily fluids, using a degreasing detergent. Cultures were collected on a randomly selected day; the curtains therefore could have been recently washed or could have gone up to seven days without washing. This approach was intended to recreate the normal circumstances faced by a patient arriving in emergency care or being admitted to one of the units described above. For culture collection, a 25 cm² area was marked midway between the top and bottom of the curtain along the side edge most frequently grasped when opening and closing it. Wearing a sterile surgical glove, the investigator simulated opening and closing the curtain and then pressed the fingers and palm onto Petri dishes containing three different culture media: MacConkey agar, azide agar, and chocolate agar (Biomérieux). The aim was to identify all microorganisms potentially colonizing curtains in each area. The Petri dishes were incubated at 35.5°C for 72 hours. All recovered bacteria were then isolated and identified in accordance with Clinical and Laboratory Standards Institute guidelines (11), using an automated system (Vitek 1, Biomérieux).
Results
After all colonies grown on the Petri dishes inoculated in each clinical area were isolated, methicillin-susceptible S. haemolyticus, methicillin-susceptible S. epidermidis, Stenotrophomonas maltophilia, and A. baumannii were identified. Their distribution differed according to the critical area from which each culture had been obtained (Figure 1).
High percentages of methicillin-susceptible S. haemolyticus and S. epidermidis were found in the emergency department (65% and 38%, respectively). The presence of A. baumannii and S. maltophilia is noteworthy because, although detected at lower percentages (12% and 8%, respectively), the findings are highly significant given the well-known potential risk associated with colonization by these organisms.
Similarly high percentages of methicillin-susceptible S. haemolyticus and S. epidermidis were found in the transition area (68% and 52%, respectively). Again, the presence of A. baumannii and S. maltophilia at lower percentages (7% and 3%, respectively) is noteworthy. On the second floor, only methicillin-susceptible S. haemolyticus and S. epidermidis were isolated (41% and 16%, respectively); neither A. baumannii nor S. maltophilia was detected.
In the intensive care unit, only methicillin-susceptible S. haemolyticus and S. epidermidis were isolated (35% and 32%, respectively). Finally, in the intermediate care unit, methicillin-susceptible S. haemolyticus and S. epidermidis were detected at 19% and 14%, respectively. Neither A. baumannii nor S. maltophilia was found in the intensive or intermediate care units.
Discussion
Healthcare-associated infections have become a serious health problem in the care of highly complex patients. Their origins and risk factors vary considerably among institutions, although some factors are common to all, including contact with different fomites. These objects not only act as reservoirs but also contribute to the spread of hospital pathogens through healthcare workers’ hands, facilitating colonization and subsequent infection among patients attending hospitals and clinics.
For several years, the medical literature has identified hospital curtains, neckties, gowns, and even mobile phones as emerging risk factors or facilitators in the spread of hospital microorganisms (10,12). Until now, however, this issue had not been confirmed in Colombia. This study identified the pathogens colonizing curtains in the different departments of a tertiary-care clinic and found clear differences in the types of pathogens according to the area evaluated. In this respect, the emergency and transition areas are points of contact between the hospital environment and the community. Multidrug-resistant hospital organisms such as A. baumannii and S. maltophilia were found there. These organisms can colonize and later infect vulnerable patients, who do not need to be hospitalized to acquire them; simply visiting the emergency department and contacting one of these fomites can lead to rapid colonization and, depending on the person’s health status, infection. These pathogens act as true opportunists capable of seriously compromising a patient’s health. The issue is not limited to curtains. Numerous studies have documented the importance of the hospital environment in acquiring healthcare-associated infections (13). The intensive care unit may be one of the most extensively studied settings because of its high incidence of infection. Research has shown that not only staff members’ hands but also countless fomites—including blood-pressure cuffs, stethoscopes, containers, and even thermometers—have been implicated in spreading hospital pathogens.
This is the first study in Colombia to explore whether hospital curtains may have become a new risk factor or fomite facilitating the spread of hospital-acquired pathogens both within and outside healthcare facilities. Although the study did not conclusively demonstrate pathogen transmission from curtains to patients, the sampling method supports this possibility. Based on these findings, each institution should confirm the results in its own setting to determine whether curtains, as observed at the clinic studied here, may play an important role as a new risk factor for acquiring hospital pathogens. While these data are being confirmed, curtains should be considered a potential source of hospital pathogens. Handwashing after contact with them should therefore be standardized, and frequent cleaning should be governed by protocol rather than performed only when curtains are visibly soiled.