The hazards associated with the consumption of dispensed ice have been recognized by the healthcare community for some time (Wilson I.G., 1997). Although hospitals take the utmost care to abide by the strictest cleaning regimens, ice machines remain susceptible to airborne contamination the moment cleaning solutions are fully flushed from the machines. The contamination comes from the ambient air which is drawn through the food zone as a result of the condenser fan. The guidelines set forth by the CDC recommend for hospital staff to clean, disinfect, and maintain ice machines as per manufacturer recommendations. These guidelines fail to take into account the inherent inability to protect the water or ice, in the ice machine, from the introduction of airborne contaminants. Reports exist which implicate ice machines in nosocomial infections, pseudo-outbreaks, and the direct contamination of other healthcare related products that come in contact with patients. In many cases, investigative cultures were taken from hospital ice machines and a variety of microorganisms were identified to reside within and in the vicinity of those ice machines. All factors considered, the necessity for a safer alternative becomes apparent, especially reflecting upon patient safety and hospital liability. Some examples of such reports follow.

In a 720-bed university teaching hospital, a 66-year-old male developed nosocomial pneumonia due to Legionella pneumophila serogroup 6 after 3 months in an ICU. As the patient had been ventilated mechanically, and had not consumed anything with the exception of ice chips since admission, the ice machine (Follet Corp, Easton, PA) became the prime suspect. Cultures of the ice machine servicing the ICU revealed legionella pneumophila present in the ice and water reservoir within the ice machine. Culture of the supply hose to the ice machine also tested positive, however, the adjacent sink, supplied by the same plumbing, tested negative. Furthermore, the filter servicing that particular plumbing line tested negative for L. pneumophila as well. Additional cultures were taken from other potential sources of infection, but no colonization of L. pneumophila was found. Thus confirming initial suspicions, it was concluded that ice machines have the potential to contain reservoirs of legionella pneumophila, and was the probable source of the infection. While a decontamination procedure was outlined in the report, it remained just that, as opposed to a viable preventative measure against further contamination. (Graman PS, 1997)

In 2001, at the Johns Hopkins Hospital, the hospital's infection control staff recognized a high number of sputum samples yielding Mycobacterium fortuitum from patients housed on a particular ward. A retrospective case-control study was implemented to identify any risk factors regarding an outbreak or pseudo-outbreak of M. fortuitum, as well as the source of this pathogen. In regards to the source, those assigned to the study obtained samples from the water and the ice machine that serviced the ward, among other locations. Specifically on the ice machine that serviced the affected ward, they sampled: "the cold water supply as it entered the machine, from the filter, from the area between the filter and the reservoir. In addition, ice samples from the augur bin and collecting containers were also cultured." (Gebo K.A., 2002) Upon testing samples taken over a period of 13 months, they found that all of the samples originating from the ice machine yielded M. fortuitum. Furthermore, no other location tested positive for M. fortuitum, including tap water samples from the affected ward. Upon identifying the machine as the source of the pseudo-outbreak, they removed it from service. The report mentions that the hospital adhered to the formal guidelines by the CDC for reducing contamination of ice machines, yet contamination was still a problem. Despite implementation of both vinegar and bleach as cleaning solutions, samples taken from the cleaned machines continued to grow M. fortuitum after 6 and 21 days respectively. (Gebo K.A., 2002)

A 79-year-old patient developed Legionnaire's disease 2 days after being dismissed from the hospital. Upon diagnosis, the hospital's infection control began an investigation into the source, sampling all areas with the potential to expose Legionella to the patient. Among the samples collected, the only that were found to be positive were the water samples, swabs and ice cubes originating from the ice machine that supplied the patient with the ice, for ice water. The hospital staff maintains that they followed a rigorous maintenance and decontamination regimen on all potable water sources within their hospital. Each ice cube sampled contained between 1-250 colony-forming units (CFU), and the water from the ice machine contained an average CFU count of 6626 CFU's per liter. Bencini et al postulated that the heating of cold-water lines in the ice making process might aid in the colonization of Legionella. (Bencini M.A., 2005)

Ice machines do not constitute a potential source of infection for patients alone. They are also a potential source for contamination of other medical products. In July of 2008, the CDC and the Arizona Department of Health Services began an investigation into a pseudo-outbreak of Legionnaires identified from cultures obtained from bronchoscopies of 4 patients being treated at an Arizona medical center. While a report on the investigation affirms that the patients did not have Legionnaires' disease, it firmly implicates an ice machine in the contamination of the samples. An endoscopy technician reported to have used non-sterile ice from a commercial ice machine to cool sterile saline flushes in prefilled syringes used for bleeding control among patients undergoing bronchoalveolar lavage. To identify a source of the contamination, samples were sent to the Legionella lab at the CDC, where L. pneumophila serogroup 8 was isolated from the samples taken from the 2 ice machines used by the endoscopy staff. The isolates were identical to the isolates obtained from the patient samples. (MMWR, 2009) A similar case saw a few cases of keratitis caused by mycobacterium szulgai. 5 patients developed keratitis after a LASIK procedure, and the source of the m. szulgai was an ice machine that provided the ice used to chill syringes of saline solution for intraoperative lavage. Samples taken from the ice machines drain proved to be the exact strain affecting those patients. The report also stated that the ice machine cleaning procedures utilized by the facility were conducted as little as 5 days before one of the cases presented. (Holmes G.P., 2002)

As can be seen from these cases, ice machines represent a potential source of nosocomial infection, contamination, and general uncleanliness in medical care facilities. However, recent discoveries could serve to shed new light on past reports implicating ice machines as the source of a nosocomial infection, or pseudo-outbreak. It was recently discovered that a high percentage of commercial ice machines currently servicing U.S. healthcare facilities were moving unfiltered air through the foodzone, against the FDA code. If this discovery was available at the time these reports were made, it is possible that blame would favor airborne contamination, especially when the water supply was found not to be the source. Further reading regarding these cases, and other cases involving ice machines can also be found here.

Back to Top