Hospital Water Faucets Harbor Pathogens, Study Reveals

A study of water-delivery systems in hospitals revealed that there is a higher level of contamination by infectious pathogens in faucets with tap aerators.

Researchers found that there was less of a pathogen presence in the same water when sampled from deeper in the same plumbing systems, which suggests that the tap aerators, which are commonly screwed into to the bottoms of faucets to provide a non-spashing stream of water and air, may be harboring pathogens.

"Aerators are a reservoir for drug-resistant bacteria and a source of infection for patients at risk," said Maria Luisa Cristina, a lead author of the study, which is published in Infection Control and Hospital Epidemiology. "Safe water is vital to ensuring patient safety where waterborne infections increase morbidity, mortality, treatment costs, compensation claims and prolong hospital stays."

Cristina, from the University of Genova in Italy, and her colleagues studied cold and hot water samples at two Italian hospitals for a year. The faucets they monitored were used by healthcare professionals for handwashing, surgical washing, and washing of medical equipment.

For their experiment, the researchers tested water from faucets with tap aerators, then removed the aerators, sterilized them and tested the water again after it had ran through a sterile aerator for two minutes.

They found that the total microbial load was 10 times greater when the aerators were first in place than after they had been sterilized.

Microorganisms like Legionella spp., Acinetobacter spp. and other Gram-negative bacteria were observed in significantly higher levels at the faucet than in the plumbing system.

"Hospitals tend to have large, complex waterworks with low-flow areas that produce stagnation and biofilm formation; hot and cold water temperatures that are not well regulated may be ideal for bacterial growth," said researcher Tara Palmore, adding that the work is "valuable in quantifying the frequency, magnitude, and location of the potential hazard to patients from hospital water in their facilities."

Palmore added that there is "still a significant gap in our understanding of how and when such risk translates to patient infections."