Infection control practitioners, scientists and epidemiologists convened to review this problem at the annual meeting of the Society for Healthcare Epidemiology of America (SHEA) in Los Angeles. Joseph Cervia, MD, a leading infectious disease expert, professor of Clinical Medicine and Pediatrics at Albert Einstein College of Medicine and Medical Director of Pall Corporation (NYSE: PLL) presented the latest information on water as an emerging threat in the healthcare environment.
"Infections acquired in hospitals and healthcare institutions affect approximately two million people resulting in about 98,000 deaths at a cost of $29 billion in the United States each year," said Dr. Cervia. "We know that tap water, previously unrecognized as a source of many of these infections, harbors pathogenic microorganisms that can pose a significant health threat to patients, especially those with weakened immune systems. By all accounts the prevalence of infections caused by some of the most potentially lethal waterborne microbes, such as legionella and pseudomonas, are underestimated."
He explained that waterborne microbes- -bacteria, viruses, fungi and parasites --can enter into the healthcare environment in several ways: direct contact with or ingestion of drinking water or ice, breathing aerosols from showers and faucets and even from improperly reprocessed medical devices. As hospitals increasingly recognize the risks to patient health, they are employing a variety of treatment technologies to attempt to eradicate microbes from incoming water. Dr. Cervia described the different types of systemic disinfection methods used and the advantages and disadvantages of each.
"Despite the range of technologies being applied, the problem of waterborne microbes in the healthcare setting continues to persist," explained Dr. Cervia. "Each of the systemic methods are limited in their ability to prevent patient exposure to waterborne pathogens because they cannot completely reach and permanently destroy biofilm."
Biofilm is a Key Culprit
Biofilm is a community of numerous types of microbes that attach to internal pipe surfaces, faucets and showerheads where they thrive and multiply. The force of water passing through the pipes or tap can break off fragments of the biofilm transferring it to different parts of the water distribution system and seeding formation of new biofilm colonies.
When water enters a hospital room from a faucet or shower, tiny water droplets containing the biofilm contaminants separate from the main water stream and spread by air currents in all directions. Some of these contaminants are inhaled as aerosols (tiny water droplets containing microbes) or condensed on surfaces where they can be touched.
Many of the bacteria found in biofilm, such as legionella pneumophila, are exhibiting resistance to commonly used water treatment methods as well as to the antibiotics used for treating infected patients. Further complicating the problem, some of these harmful pathogens are also protected by amoeba that are resistant to chlorination, temperature and osmotic pressure. The amoeba acts as a "Trojan Horse" harboring and transporting the microbes. Amoebas with waterborne resistant microorganisms have been recovered from drinking water, cooling towers and water distribution networks in hospitals.
Dr. Cervia presented data on the efficacy of point-of-use 0.2 micron filters to provide a barrier to Legionella and other pathogens to reduce the risks from hospital water. Unlike systemic technologies, filtration can significantly reduce the release of pathogens, biofilm and the aerosols they create. He explained that several European nations already recommend point-of-use 0.2 micron filters as a simple and effective solution to prevent waterborne microbe transmission to patients. He reviewed the results of studies conducted with Pall-AquasafeTM filters, which are specifically designed to prevent patient exposure to waterborne microbes. The filters provide an absolute barrier between the microorganisms and patients.
"Point-of-use filtration is a effective solution that can be easily applied to all types of water systems -- showers, faucets, and even ice machines -- especially in hospitals areas where the most vulnerable patients reside," he said.
Taking Action to Help Protect Patients
Dr. Cervia said hospitals throughout North America are increasingly turning their attention to water as a source of nosocomial (hospital-acquired) infection as a result of recognition of the prevalence and risks posed by waterborne pathogens. However, he noted, there is a great deal more to be done.
He stated that the infectious disease community can take the lead in solving the problem and that they can also look to the experience and success in Europe to ensure that patients are protected from dangerous waterborne pathogens.
Health and government agencies continue to stress the need for more stringent approaches to dealing with nosocomial infections, such as the new infection control standards mandated by the Joint Commission on Accreditation of Healthcare Organizations (JCAHO), as part of their 2005 National Patient Safety Goal. State legislative initiatives across the U.S. in addition to public education campaigns by several organizations are also pushing for hospitals to alert the public to their infection rates.