Study Finds Some Harmful Microbes Linger After Disinfection

A new study recently published in the American Journal of Infection Control (AJIC) found microbial contamination—including pathogenic and potentially pathogenic bacteria—on high-touch hospital surfaces despite compliance with recommended disinfection protocols.

The study was conducted between June and July 2022 at the Central Texas Veterans Healthcare System, where researchers collected samples from 400 high-touch surfaces, including simulation manikins used for resuscitation practice, workstations on wheels, break room tables, bed rails, and computer keyboards at nurse’s stations. These surfaces all were found to harbor bacteria; manikins and bed rails had the most diverse types of bacteria.

A total of 60 different kinds of bacteria were identified, including 18 well-known human pathogens and a number of bacteria that can be pathogenic to humans under certain circumstances. The most common types of known pathogenic bacteria included, among others, Enterococcus, Staphylococcus aureus, Streptococcus, Escherichia coli (E. coli), and Klebsiella aerogenes. Some of the potentially pathogenic types of bacteria have been associated with central-line associated bloodstream infections, meningitis, and endocarditis. About half of the bacteria identified through these samples were also found in clinical samples collected from patients during 2022.

According to the AJIC, the findings shed light on the persistent challenge of reducing healthcare-associated infections (HAIs) and indicate that innovative strategies might be needed for more effective disinfection of these surfaces. As this new study demonstrates, current best practices in routine hospital disinfection might not be sufficient to prevent the spread of pathogens, particularly for surfaces that are frequently touched by many different people.

“It is a continuing frustration to healthcare professionals that HAIs persist despite rigorous attention to disinfection practices,” said Piyali Chatterjee, Central Texas Veterans Healthcare System research scientist and senior author of the report. “Our study clearly shows the bioburden associated with high-touch hospital surfaces—including simulation manikins, which are not typically regarded as a risk because patients rarely touch them—and indicates that we must do better in protecting the health of our patients and our hospital employees.”

“This study underscores the critical value of infection prevention and control efforts in our healthcare systems,” said Tania Bubb, Association for Professionals in Infection Control and Epidemiology (APIC) president. “By understanding the gaps in our current disinfection protocols, we can focus on developing more effective protocols and education strategies to prevent the spread of dangerous organisms and better protect patients and healthcare workers from HAIs.”