New research has found significantly higher levels of infectious germs in water from hospital faucet taps with aerators compared to water deeper in the plumbing system, posing an increased risk to sick patients with compromised immune systems.
 

The research, published in the journal Infection Control and Hospital Epidemiology and reported by Medical Xpress, found bacteria levels in cold and hot were up to 10 times greater when faucet aerators were in place than after they had been sterilized. The study identified such micro-organisms as Legionella spp., Acinetobacter spp. and other bacteria that were significantly higher at the faucet than in the plumbing system.
 

The tests, led by researchers from the University of Genova in Italy, also showed chlorine levels were consistently too low to kill the bacteria.
 

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

For the study, researchers analyzed cold and hot water samples — at the tap and deeper in the plumbing systems — at two hospitals for a year from faucets used by healthcare professionals for handwashing, surgical washing, and washing of medical equipment.
 

Water sampling was carried out first with the aerators in faucets in place and then after disinfecting and flame-sterilizing the outlet and letting the water run for two minutes.

The results showed the total microbial load was up to 10 times greater when aerators were in place than after they had been sterilized.
 

In a commentary published alongside the study, Tara Palmore, M.D., said the findings spotlight the need for more research on the topic.
 

"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...the work of Cristina et al. is valuable in quantifying the frequency, magnitude, and location of the potential hazard to patients from hospital water in their facilities," said Dr. Palmore. "There is still a significant gap in our understanding of how and when such risk translates to patient infections."