The study suggests that hospital floors may be a source of infection that spreads through contact with high-touch objects.
The team - including researchers from the Case Western Reserve University School of Medicine in Cleveland, OH - reports the study in the American Journal of Infection Control.
Healthcare-associated infections are infections that patients acquire during admission to a healthcare setting such as a hospital or nursing home. They are a major, but often preventable, threat to patient safety.
Healthcare-associated infections are most often linked to the use of invasive devices such as central lines, ventilators, and urinary catheters. They can also develop following an operation, at the place on the body where surgery was performed.
Patients treated in intensive care units (ICUs) are at particular risk for infection, and the risk rises with the amount of time spent in ICUs.
According to the World Health Organization (WHO), healthcare-associated infections are the "most frequent adverse event" in the delivery of healthcare worldwide. They affect hundreds of millions of patients every year and are linked to significant numbers of deaths and high healthcare costs.
The annual financial losses attributed to healthcare-associated infections in the United States are estimated to be in the region of $6.5 billion.
The Centers for Disease Control and Prevention (CDC) say that much progress has been made in tackling healthcare-associated infections, but there is still a lot of work to do. They estimate that at any given time in the U.S., around 1 in 25 hospital patients has at least one infection associated with healthcare.
Floors not classed as frequently touched surface
The researchers behind the new study suggest that their findings highlight an area that may be overlooked in measures to prevent and control healthcare-associated infections.
They note that: "Efforts to improve disinfection in the hospital environment usually focus on surfaces that are frequently touched by the hands of healthcare workers or patients."
Even though floors are heavily contaminated, because they are not classed as a frequently touched surface, they do not receive as much attention as high-touch objects, they add.
For their study, the researchers investigated five hospitals in the Cleveland area. Altogether, they cultured and examined samples from 318 floor sites from 159 patient rooms (two sites per room), including C. difficile infection (CDI) isolation rooms and non-CDI rooms.
They also took samples from the bare and gloved hands of healthcare staff, as well as from other high-touch surfaces including call buttons, medical devices, linen, medical supplies, and clothing.
High-touch objects often in contact with contaminated floors
The results showed that floors in patient rooms were often contaminated with MRSA, vancomycin-resistant enterococci, and C. difficile, with C. difficile being "the most frequently recovered pathogen in both CDI isolation rooms and non-CDI rooms."
The researchers also found that high-touch objects, including call buttons and blood pressure cuffs, were frequently in contact with the floor, and contact with objects on the floor often led to the transfer of pathogens to hands.
They suggest that further research should now be done to investigate the extent to which the floors of hospital rooms might be an underappreciated source for the spread of pathogens.
Linda Greene, president of the Association for Professionals in Infection Control and Epidemiology, says that: "Understanding gaps in infection prevention is critically important for institutions seeking to improve the quality of care offered to patients," and concludes:
"Even though most facilities believe they are taking the proper precautions, this study points out the importance of ensuring cleanliness of the hospital environment and the need for education of both staff and patients on this issue."