The Hidden Threat of Hospital Sink Drains

A new study published in Frontiers in Microbiology has revealed that hospital sink drains can be a common source of scary, drug-resistant pathogens, even after deep cleaning. Researchers at the University of the Balearic Islands in Spain led the study, which analyzed bacteria collected from drains around a single, well-maintained hospital on the island of Majorca.

The Spread of Superbugs

Antibiotic resistance is one of the most pressing public health issues of our time. It’s already estimated that these infections kill at least 1.27 million people worldwide annually, including 35,000 Americans a year. And studies have projected that drug-resistant bacteria will eventually match or even surpass the current annual death toll of cancer (roughly 10 million deaths a year) in the next few decades.

Hospitals as Breeding Grounds for Superbugs

Hospitals and other healthcare facilities are common breeding grounds of antibiotic resistance for several reasons. Antimicrobials are widely used in these places, directly fueling resistance. Patients are also in poorer health than usual, making it easier for infections to prosper and spread like wildfire between people. Given these known risks, hospitals and their employees routinely take steps to mitigate antibiotic resistance, which often includes the deep cleaning of areas where bacteria can linger, such as plumbing systems and sink drains.

The Study’s Findings

The researchers analyzed sink drains from a single university hospital on the island of Majorca that was built in 2001. They collected bacterial samples from six sink drains in five wards and genetically sequenced them. The results showed that:

• 67 different bacterial species were found in the drains, including superbugs that can resist several antibiotics at once.
• The drains contained a wide range of bacteria, including strains commonly associated with serious hospital-acquired infections.
• The cleaning procedures used by the hospital did not seem to have much of an effect on the overall diversity of bacteria found in the drains.

The Bacteria That Worry Researchers

The researchers identified strains of bacteria that were resistant to multiple antibiotics, including:

• Pseudomonas aeruginosa and Klebsiella pneumoniae, which are known to be resistant to several antibiotics.
• A worrying gene that promotes resistance to carbapenems, a newer class of antibiotics often used as a last resort treatment for infections that have stopped responding to other drugs.

What’s Next

While the researchers aren’t saying that hospitals should stop cleaning their sink drains, they are highlighting the need for more to be done to stop or slow down the proliferation of superbugs within these environments. "Cleaning protocols are important and should be frequently applied, especially in wards that are kept separate precisely to slow the spread of potentially harmful bacteria," said lead researcher José Laço. "But to get to the bottom of the problem, it’s essential to study the source of these bacteria and their routes of transmission."

The Importance of Further Research

As the study’s findings suggest, hospital sink drains can be a significant source of antibiotic-resistant bacteria. Further research is needed to understand the routes of transmission and to develop effective strategies for preventing the spread of superbugs in these environments. By working together, we can reduce the risk of antibiotic-resistant infections and protect public health.