Hospital Sinks May Contain Dangerous Bacteria: Study

New research suggests that dangerous bacteria is commonly found in hospital sinks that are located next to toilets, posing a risk of serious infections for individuals who may already have a compromised immune system. 

In a study published in the January 2019 issue of the American Journal of Infection Control, researchers from Duke University found that nearly 90% of sinks next to toilets in hospital bathrooms were infected with Klebsiella pneumoniae carbapenemase (KPC), which can cause pneumonia and different types of “superbug” infections that may be resistant to antibiotic resistant.

Researchers took samples from a 600-bed medical intensive care unit (ICU) in a Milwaukee, Wisconsin hospital. The ICU did not have any documented KPC infections or patient interactions with KPC within the past year.

The rooms included two sinks, one near a door and another on the other side of the room near a toilet. There were no barriers between the toilet and the two sinks. The sinks were cleaned with disinfecting agents and separate cloths to avoid cross-contamination.

Researchers found that sinks near the toilet were four times more likely to be positive for KPC than the sinks away from the toilets, with the bacteria found in 87 percent of those sinks. Comparatively, only 22 percent of sinks located near the entry door on the other side of the room tested positive for KPC.

In four out of five rooms where the sink near the entry door did test positive, the sink near the toilet was also positive. This suggests there may have been some source of cross-contamination within the same room.

Klebsiella pneumoniae carbapenemase is a bacteria that can cause many infections including pneumonia, bloodstream infections, wound infections, or surgical site infections.

In recent years, KPC has become antibiotic resistant. Most recently, KPC has become resistant to a class of antibiotics known as carbapenems.

Researchers said they are unclear exactly how the contamination occurs. Sinks were cleaned in the patient rooms; however, sink pipes were not. A 2017 study testing the spread of bacteria in hospital sinks found biofilms growing in pipes spread to the drains. Biofilms are often difficult to kill with chemicals. A similar study published in 2018 indicated many antibiotic-resistant bacteria was found in the plumbing of hospitals.

Another theory is flushing a toilet generates contaminated drops that reach the sink drains.

The new study suggests a need for interventions to help prevent the spread of infectious disease bacteria, like KPC, through hospital plumbing and fixtures, the researchers determined. Those interventions could include modified hand hygiene and washing protocols as well as updated sink and plumbing disinfection protocols.

This is the first study to directly examine the importance of sink and toilet location in patient rooms regarding the frequency or likelihood of bacteria transmission.