Hospital water faucet taps contaminated with bacteria
Researchers in Italy found that water from hospital faucet taps with aerators had higher levels of contamination with bacteria than water from deeper in the plumbing system.
“Aerators are a reservoir for drug-resistant bacteria and a source of infection for patients at risk,” Maria Luisa Cristina, PhD, of the department of health sciences at the University of Genova, said in a press release. “Safe water is vital to ensuring patient safety where waterborne infections increase morbidity, mortality, treatment costs, compensation claims and prolong hospital stays.”
Cristina and colleagues analyzed microbiological and chemical-physical characteristics of 304 water samples for 1 year. They collected hot and cold samples from critical hospital departments at two hospitals in Italy. The samples were taken from faucet taps used for hand-washing, surgical washing and washing medical equipment. The researchers analyzed heterotrophic plate counts at 36°C and 22°C, nonfastidious gram-negative bacteria (GNB-NE) and Legionella pneumophila.
They found that the heterotrophic plate counts at 36°C and 22°C, as well as the GNB-NE loads were significantly higher at outlet points than they were in the plumbing system. GNB-NE load was higher in cold tap water vs. the plumbing system (31.58% vs. 6.58%) and in hot tap water vs. the plumbing system (21.05% vs. 3.95%).
The researchers also found that Legionella spp., Acinetobacter spp. and other gram-negative bacteria were higher at the faucet than in the plumbing system. They found that the chlorine levels were too low and that the hot water temperatures were below the minimal temperature needed to prevent the growth of Legionella.
In an accompanying editorial, Brooke K. Decker, MD, and Tara N. Palmore, MD, of the NIH, said additional research is needed to understand the effect of these data.
“Hospitals tend to have large, complex waterworks with low-flow areas that produce stagnation and biofilm formation,” they wrote. “Hot and cold water temperatures that are not well-regulated may be ideal for bacterial growth. This work is valuable in quantifying the frequency, magnitude and location of the potential hazard to patients from hospital water in their facilities. There is still a significant gap in our understanding of how and when such risk translates to patient infections.”
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Disclosure: Cristina, Decker and Palmore report no relevant financial disclosures.