Microbiologists will be interested to learn of new research designed to better identify sources of hospital-acquired infections, including investigating possibilities that have not been previously considered

Does the proximity of toilets to sinks in medical intensive care units (MICUs) affect the health and recovery of the patients staying there? Until recently, that wasn’t questioned. But clinical laboratory managers will be interested to learn why researchers now believe this could very well lead to nosocomial infections—also known as hospital-acquired infections (HAIs)—a topic Dark Daily has covered extensively for many years.

Researchers at the Medical College of Wisconsin (MCW), Milwaukee, found that sinks located near toilets in patient rooms were four times more likely to have Klebsiella pneumoniae carbapenemase (KPC)-producing organisms in their drains than sinks that were located farther away from toilets, according to an Elsevier press release.

In a study published in the American Journal of Infection Control (AJIC), a journal of the Association for Professionals in Infection Control and Epidemiology (APICE), the authors wrote that no other formal research had been conducted to determine whether the location of sinks in patient rooms is relevant to the spread of infections.

Thus, the results of this research could impact not only the hygiene and disinfectant procedures of healthcare workers, but the designs of future MICU rooms and possibly even change the plumbing requirements throughout entire healthcare facilities. These new findings may also create new factors for hospital infection control teams and microbiologists to consider when investigating the sources of nosocomial infections.

The MCW researchers conducted their investigation in a 600-bed Wisconsin hospital with a 26-bed MICU “in which each room has:

  • “a patient bed;
  • “two sinks; and,
  • “a toilet without physical barriers in between.

“Each room is surface-cleaned (including sink bowls, but not drains) with hydrogen peroxide/peracetic acid on a daily basis. Separate cloths are used to clean each of the two sinks in patient rooms to avoid cross-contamination,” the study notes.

Photo copyright: Medical College of Wisconsin, Milwaukee

The photo above (taken from the MCW study) illustrates the configuration of the medical intensive care unit room surveyed in this study. The location of the toilet with a sink adjacent to the toilet and sink far from the toilet are all labeled. (Photo copyright: Medical College of Wisconsin, Milwaukee.)

The MCW researchers found:

  • “KPC–producing organisms persist in sink drains in intensive care units without recent history of carbapenem-resistant Enterobacteriaceae infections;
  • “A high prevalence of [beta-lactamase Klebsiella pneumoniae carbapenemase] (blaKPC) polymerase chain reaction-positive (54%) and culture-positive (9%) sink drains; and,
  • “Sinks near toilets were four times more likely to be positive (87%) than sinks distal to toilets (22%).”

However, the MICU did not have any documented interactions with KPC-producing organisms within the past year, the press release noted.

“This study, if validated, could have major implications for infection control,” study authors, Blake Buchan, PhD (left), and Silvia Munoz-Price, MD, PhD (right), stated in the press release. “If sinks next to toilets are indeed a reservoir for KPC, additional interventions—such as modified hand hygiene practices and sink disinfection protocols—may be needed to stem the risk of transmission among healthcare providers and patients alike.” (Photos copyright: Medical College of Wisconsin.)

“This study, if validated, could have major implications for infection control,” study authors, Blake Buchan, PhD (left), and Silvia Munoz-Price, MD, PhD (right), stated in the press release. “If sinks next to toilets are indeed a reservoir for KPC, additional interventions—such as modified hand hygiene practices and sink disinfection protocols—may be needed to stem the risk of transmission among healthcare providers and patients alike.” (Photos copyright: Medical College of Wisconsin.)

Other Studies into KPCs, HAIs, and Human Gut Microbiota

Another study, which looked at the risk factors for carbapenem-resistant KPC (CRKP) in pediatric patients in Beijing Children’s Hospital, found that hematologic malignancies and previous cephalosporin administration were better predictors of mortality due to CRKP bloodstream infections than mechanical ventilation for septic shock.

And, in a study published in the Oxford Academic journal Clinical Infectious Diseases, researchers associated with the Rush University Medical Center in Chicago, and the University of Michigan Medical School, Ann Arbor, found that “increased relative abundance of Klebsiella pneumoniae carbapenemase-producing Klebsiella pneumoniae within [human] gut microbiota is associated with risk of bloodstream infection in long-term acute care hospital patients.”

Dark Daily reported on a similar study conducted at Stanford University School of Medicine last year. (See, “Stanford University Study Traces Hospital-Acquired Bloodstream Infections to Patients’ Own Digestive Tract,” November 19, 2018.)

New technologies that allow researchers to follow novel, unexplored paths to learn about potential sources of infections might contribute to fewer hospital-acquired infections and improved outcomes for both patients and those who work in healthcare settings.

Medical laboratories play a critical important role in this by identifying and typing bacteria in hospital settings, especially those that are resistant to current antibiotics. New approaches to locating such bacteria continue to be investigated and the tools available to learn more about them are becoming more powerful and widely available.

Regardless of the origin, protecting staff and patients from HAIs is critical. Clinical laboratory involvement in protecting patients, and monitoring, investigating, and managing outbreaks, are key to controlling the spread of these dangerous bacteria.

—Dava Stewart

Related Information:

A Reservoir of Bacteria: Sink Drains Next to Toilets In Patient Rooms May Harbor Dangerous Organisms

The Relevance of Sink Proximity to Toilets on the Detection of Klebsiella pneumonia Carbapenemase Inside Sink Drains

Risk Factors for Carbapenem-resistant K. pneumonia Bloodstream Infection and Predictors of Mortality in Chinese Pediatric Patients

Increased Relative Abundance of Klebsiella pneumoniae Carbapenemase-producing Klebsiella pneumoniae Within the Gut Microbiota Is Associated with Risk of Bloodstream Infection in Long-term Acute Care Hospital Patients

New Molecular Diagnostic Approaches to Bacterial Infections and antibacterial Resistance

Stanford University Study Traces Hospital-Acquired Bloodstream Infections to Patients’ Own Digestive Tract