Infectious Pathogens Higher In Water From Hospital Water Taps With Aerators
January 22, 2014

Bacteria Contaminates Hospital Faucets, Aerators Carry Bulk Of The Microbial Load

April Flowers for - Your Universe Online

A new study, led by the University of Genova, Italy, finds that infectious pathogen levels are higher in water obtained from hospital water taps with aerators than water from deeper in the plumbing system. Patients who are immunocompromised are at a higher risk of infection from such contaminated water.

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

Hot and cold water samples from two tertiary care hospitals were collected for a year by the research team. The samples were collected from faucets used by healthcare professionals for handwashing, surgical washing and washing of medical equipment.

The growth of bacteria at both the faucet and deeper within the water distribution system was tracked by the researchers who carried out hot and cold water sampling using two methods. First, they took samples with the aerators in faucets in order to assess the risk at each outlet point. Second, they disinfected and flame sterilized the outlet point, then let the water run for two minutes to analyze the microbiological features of the plumbing system.

The total microbial load was found to be 10 times greater when aerators were in place, the researchers report, than after they had been sterilized. Opportunistic micro-organisms, such as Legionella spp., Acinetobacter spp. and other Gram-negative bacteria were shown to be significantly higher at the faucet than deeper in the plumbing system. Consistently low chlorine levels and hot water temperatures that were below the minimal temperature needed to prevent the growth of Legionella were noted throughout the study. These factors are both known to promote the growth of waterborne pathogens.

Dr. Tara Palmore, MD, is a research specialist in infectious diseases at the National Institutes for Health (NIH) commented on the study, noting the need for additional 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. There is still a significant gap in our understanding of how and when such risk translates to patient infections."

The findings were published recently in the journal Infection Control and Hospital Epidemiology.