Hand hygiene is one of the simplest, most basic practices that prevents the spread of infection. But we can’t forget what is left behind in the sinks in which hand washing is done. Sinks become a reservoir for pathogens, deposited in the pipes and coming from the hands that are washed using them. Biofilms form in the pipes and can be aerosolized from drips and running water, putting the dangerous makeup of those biofilms in a position to be spread. Additionally, drinking water can be adversely affected when we fail to recognize and address biofilms.

One of our microbiologists a few years back was called to a hospital to consult about an infection control program. A room they examined had a series of deaths linked to pseudomonas. Not surprisingly, a swab of the sink exposed a pseudomonas biofilm. Pseudomonas is a type of bacteria (germ) that is found commonly in the environment, like in soil and in water. Of the many different types of Pseudomonas, the one that most often causes infections in humans is called Pseudomonas aeruginosa, which can cause infections in the blood, lungs (pneumonia), or other parts of the body after surgery.

From one of the studies linked below: Several non-hand hygiene activities took place regularly in ICU handwashing sinks; these may provide a mechanism for nosocomial transmission and promotion of bacterial growth in the drain. Redesigning hospital workflow and sink usage may be necessary as it becomes apparent that sink drains may be a reservoir for transmission of multidrug-resistant bacteria.

Characterizations of handwashing sink activities in a single hospital medical intensive care unit

Pseudomonas aeruginosa in Healthcare Settings

Water Microbiology. Bacterial Pathogens and Water

Carbapenem-resistant Enterobacteriaceae dispersal from sinks is linked to drain position and drainage rates in a laboratory model system

Spread from the Sink to the Patient: In Situ Study Using Green Fluorescent Protein (GFP)-Expressing Escherichia coli To Model Bacterial Dispersion from Hand-Washing Sink-Trap Reservoirs

The relevance of sink proximity to toilets on the detection of Klebsiella pneumoniae carbapenemase inside sink drains