Air and Waterborne Pathogens are Resilient

Water is a necessary part of human life, but it is also an abettor of life-taking pathogens and air is a common germ-smuggler too.

Sick building syndrome is a big issue in healthcare facilities and makes it easier for fungus, mold and germs to infect patients and healthcare workers. Tuberculosis (TB) and other illnesses are only a cough away, in some cases, and thwarting these foes can be daunting.

As for contamination of hospital water supplies, it is a “serious problem,” says Matt Freije, a certified water specialist, founder and president of HC Information Resources Inc., a company that provides consulting and training pertaining to Legionella and other waterborne pathogens. It’s unknown exactly how many hospital-acquired infections (HAIs) are caused by waterborne pathogens, but evidence indicates that it is a significant number, Freije says.

“For example, mycobacteria, which can survive in potable water systems for several years, have been implicated in serious nosocomial outbreaks,” he says. “Nosocomial pneumonias caused by waterborne Pseudomonas aeruginosa result in approximately 1,400 deaths each year in the United States. And Legionella bacteria continue to cause thousands of nosocomial Legionnaires’ disease cases each year, not only affecting patients, but resulting in expensive lawsuits, emotional stress, wasted time, and damaging press.”

Some illnesses, such as salmonella, are usually foodborne, but can contaminate public water systems too. Although it’s rare, it can happen, as residents of Alamosa, Colo., unfortunately learned in March when salmonella in their water system sickened about 250 people. The first victim showed symptoms around March 8, and state health officials became aware of the outbreak a week later, the Associated Press reported. Alamosa’s water is drawn from a well and aquifer combination and gets pumped to buildings without chlorination.

Schools in this southern Colorado town were closed and residents were warned against using water for anything but flushing toilets, according to reports by the Associated Press. To rid the water of bacteria, crews pumped chlorine into the water supply.

Waterborne Pathogens

The problems that waterborne pathogens cause are often under-recognized. For instance, the Centers for Disease Control and Prevention (CDC) estimates that 90 percent of nosocomial Legionnaires’ disease cases go undiagnosed, Freije says.

“I have seen the lack of awareness first hand,” he adds. “In the last few months I have taught several training courses in hospitals regarding Legionella and other waterborne pathogens. Facilities and infection control personnel said that the information was eye-opening—they were not familiar with the extent of the potential problems and ways to minimize risk.”

As was shown in Alamosa, even drinking water can be a problem. The most alarming aspect is that most harmful substances (including some disease-causing microorganisms, nitrates, trace amounts of lead and mercury, and some pesticides and organic materials) have no taste.¹

The pharmaceuticals that we recently learned are in many American water systems are also tasteless. More needs to be found out before anyone will know how dangerous these drugs are or are not, and how to practically minimize the risk. In the meantime, it is probably smart to wait for more data, Freije says.

“The cost of conducting tests to ascertain the risk of pharmaceuticals and of installing a system to remove them from domestic water would be very high relative to what little is known about the risk,” he adds.

There is plenty to worry about even if the pharmaceuticals in our water aren’t dangerous. Typhoid and Cholera are the major global waterborne diseases, and Legionella, Nageleria and Ancanthamoeba are spread predominantly through water, says Joan Rose, PhD, Homer Nowlin chair in water research at Michigan State University.

Others that have are highly linked to water include Cryptosporidium, Giardia, and enteric (intestinal) viruses such as norovirus. In regards to ground water, Campylobacter and E.coli remain important as well, and all enteric microorganisms have the potential to cause waterborne disease, she adds.

“It is debated whether pseudomonas can be spread through water, however, I for one think this is a risk especially for patients who have cystic fibrosis or burns or other problems that make them highly susceptible to the bacteria taking hold,” Rose says.

Disease transmission risk is influenced by the type of microorganism, its potency, ability to survive on surfaces, grow in water, as well as the level of contamination and the type of exposure, Rose says.

“One can imagine that via the shower, you are exposed to more water (and) aerosols and you are exposed longer,” Rose says. “So in a shower if the water is contaminated, your skin is exposed, you can swallow some water and you can breathe some in, which will get caught in your nasal passages and then you swallow it or it may go to your lungs.”

Not a pretty picture

Legionella and Psuedomonas are two types of bacteria that live in water and can infect people via showers. As for contaminated surfaces, hands play a starring role. The type of surface they touch may influence how well the microorganism is transferred from the surface to hands or vice versa, Rose says.

“Handwashing and cleaning of surfaces is key to avoiding transmission and also keeping surfaces dry (because) microbes die off as the surface dries,” she adds. “How important are contaminated faucets in the transmission of diseases and which ones? My guess is that surface is of lower risk, but it is touched a lot by contaminated hands and is often wet, so there is some chance. With methicillin-resistant Staphylococcus aureus (MRSA) and Clostridium difficile being spread around, the consequence of the infection for some is so serious that the reduction of all of these potential risks is a good idea.”

Fecal viruses may be a risk as well because they are shed in high numbers, survive well and have high potency. There are not yet enough definitive answers to these problems, but in the meantime, a way to decrease risk is through making certain hands are washed and surfaces are clean and dry.

Plumbing Problems

Studies have shown that the risk of Legionnaires’ disease increases with the proliferation of Legionella bacteria in domestic (potable) water systems, and infecting the systems will terminate an outbreak, Freije says.

“However, most of those same studies lack the data to indicate whether the patients were infected by using faucets, taking showers, brushing teeth, or drinking water, although some recent data suggests that faucets may present a greater risk than showers—just the reverse of previous thought,” he adds. “For Pseudomonas, tracing transmission routes is even more difficult because patients, surfaces (the outside of faucets), and water can all contaminate one another.”

There are some precautions that healthcare facility leaders can take to ensure their storage tanks and pipes don’t have too many contaminants. First of all, they should test for quality and residuals, Rose says. They should also conduct proper maintenance, which includes flushing, cleaning, repairing old piping and shower heads, etc. Next, investigate the quality of the storage tank including the roof top, to make certain it’s protected and clean. Rose also recommends consideration of innovative point-of-use devices.

Helping hospital staffs understand how to make their storage tanks and pipes safe is seldom a brief topic, and sometimes requires Freije to conduct full-day seminars. Hospitals should implement preventive measures in the design, installation, commissioning, operation, and maintenance of domestic water systems, cooling towers, and other aerosolizing devices, he says.

“Sampling for Legionella should be conducted to validate that the preventive measures are working,” he adds. “And adjustments in the preventive measures and various remedial steps should be implemented as appropriate based on the test results.”

Busting Waterborne Pathogens

To reduce waterborne illness, hospital leaders should be familiar with their tap-water quality, know the source of their water and how much it is treated. Testing should be conducted for staph, Legionella, E. coli, Pseudomonas and maybe some other pathogens, Rose says. And for sensitive populations, extra precautions should be taken. Nature also comes into play.

“There is a relationship between season and disease,” Rose says. “We don’t understand it fully, but it would be wise to keep track of cases of disease that might be waterborne.”

In the rainy season there are more enteric diseases, as contamination seems to move with rain and impacts surface water and groundwater, she says. In winter, the survival of pathogens in water is enhanced and in summer warmer temperatures lead to more pseudomonas and Legionella, she adds.

Studies have confirmed waterborne illness associated with Legionella, Pseudomonas, and mycobacteria in domestic water systems, and there are many other potential pathogens, including viruses, for which the extent of water versus other sources is less known, Freije says.

“For example, person-to-person, not water, is considered the primary route of transmission for viruses,” he adds. “After more efficient methods of detecting viruses in water are developed, water may be found to be a significant source, but for now the data are insufficient.”

With hands, pipes, storage tanks and Mother Nature seemingly conspiring with waterborne pathogens, infection control, sterile processing and environmental services personnel need all the help they can get. Luckily, several guidelines are available for Legionella, about how to protect patients from transmission, and how to design, install, operate and maintain water systems to minimize Legionella growth,” Freije says.

“And cost effective technology is available for solving Legionella problems in water systems,” he adds. “In the United States, the guidelines are not required by law, but are often used in civil lawsuits to establish a standard of care.”

Airborne Pathogens

Environmental pathogens are absolutely a problem at healthcare facilities, and airborne pathogens are part of it, says John Pierson, infection control product manager for Fiberlock Technologies, a producer of environmental containment systems.

“If you think about the amount of work the HVAC systems do on a daily basis, and the amount of infectious agents that are present in a healthcare facility, it seems very likely that there is great opportunity for various environmental issues to arise,” Pierson says.

A well-maintained environment can mitigate foes such as TB. TB in the healthcare setting re-emerged as a major public health problem around 1989, according to researchers from the National Occupational Research Agenda (NORA), a partnership program to stimulate research and improve workplace practices. Several healthcare workers have developed active drug-resistant TB in hospitals.²

MRSA and other forms of staph can be found in nasal passages and sneezing can thereby pass the illness, Pierson says. HEPA filtration and proper personal protective equipment (PPE) can reduce the risk of airborne infection.

Although bloodborne pathogens can be transmitted through mucous membranes, there are no known instances of bloodborne pathogens being transmitted through aerosolization in a clinical setting.³ As any periopertive nurse knows, surgical instruments can create a visible spray of water, blood, microorganisms and other debris, and the spray may contain some aerosol.³

Airborne Pathogen Solutions

Dirt, dust, mold and fungus can be almost as disruptive to patient and worker health as some pathogens. One of the most important steps a facility can take is to collect pollutants and pathogens at the source, Pierson says. He recommends containment and filtration systems.

“By containing the dust and fungal spores before they have an opportunity to spread throughout the facility, you are eliminating several levels of threat to multiple areas of the facility,” Pierson says. “Using containment with negative pressure to help contain dirty areas, be it from construction and maintenance or from an infectious patient, is one of the best ways to minimize HAIs.”

According to Pierson, APIC guidelines and various studies have shown that a large portion of nosocomial infections are caused by airborne fungi and dust generated from maintenance and repair work. “Many hospitals are relatively old buildings and have had their share of water leaks, structural damage and accumulation of dust in areas that aren’t regularly maintained (above ceilings, between walls, behind sinks and hand-washing stations),” Pierson says. “As facilities are always climate controlled, these areas are perfect breeding grounds for fungi.”

Pierson recommends that any time an area could have dust accumulation or mold growth, the area should be contained under appropriate negative pressure before being disturbed. This could include plumbing work, removing ceiling tiles, cutting through walls, removing floors, etc.

However, standard negative pressure isolation rooms alone may not be sufficient in some situations. “For instance, a patient arrives to the ER with multiple wounds and internal bleeding from a car accident,” Pierson theorizes. “Upon admission it is discovered that this patient is infected with TB and is highly contagious. The situation is such that not only must this patient be isolated for the safety of other patients and workers in the hospital, but also for his/her personal safety. The OR, the patient room, recovery, ICU, all may need to be contained with an anteroom.”

The Kontrol Kube Abacus, for instance, creates a negative pressure entry vestibule between two positively pressurized environments.

As hospitals secure greater communication and network technologies, the progress often requires installation or re-working of lines and cables above ceiling tiles. This can cause a lot of dust and particulates to become airborne unless proper measures are taken. One such solution is the Kontrol Kube Topsider, which is a mobile containment unit with a rolling wheelbase for easy mobility. It reaches ceilings of up to 10 feet and is useful for HVAC repair, light fixture repair, cabling and conduit installation.

Other advice, according to Pierson, is to ensure that pre-filters and HEPA filters are up to date and to institute proper containment guidelines for maintenance work. Technology can be a big help too.

At New York City’s North Central Bronx Hospital, for instance, the staff deals with infectious particles in the bronchoscopy room by using ultraviolet germicidal irradiation (UVGI). When a microorganism in an airborne droplet nuclei passes through this irradiation, its DNA is penetrated and destroyed, which disables the microorganism’s ability to transmit disease.4 UVGI may destroy up to 99 percent of the airborne pathogens in a room if there is sufficient air mixing and resident time.4

The staff at Bronx Hospital installed two wall-mounted units that contain a fan, a washable electrostatic filter that can remove airborne particles. The bronchoscopy room installation and eight additional UVGI air sanitizers in the ER waiting room were installed in 1995 and may have been a catalyst for lower TB rates that the hospital reported in later years.4

All measures add up, and if a staff is more persistent than even the most stubborn pathogen, waterborne and airborne noscomial rates can decrease.ICT


1. Kendall P., National Ag Safety Database. Drinking Water Quality and Health, April 2002.

2. The National Occupational Research Agenda (NORA):

3. The Centers for Disease Control and Prevention:

4. Alabama Power:

Industry Provides Ways to Fight Air/Waterborne Infections



AirInSpace, a supplier of mobile devices that capture and inactivate harmful biological particles from the air, announces that it has received Food and Drug Administration (FDA) clearance to market its PlasmairT2006 by AirInSpace mobile system as a medical device. This mobile air-decontamination unit’s performance has been clinically proven to lower airborne biological loads and is now being used to combat nosocomial infection in high-risk areas of more than 100 hospitals and clinics throughout France, including hematology/oncology units and ICUs. The company will unveil a new product name for the PlasmairT2006 for the U.S. market at the annual meeting of the Association for Professionals in Infection Control and Epidemiology (APIC) to be held in Denver in June. 


Sage Products

Sage Products offers a full line of interventional patient hygiene products, including Comfort Bath cleansing to help eliminate basin bath contamination and waterborne transmission of infectious pathogens. Patient bath water is a proven, significant source of high-level bacterial contamination, while other basin uses, such as emesis and incontinence clean-up, increase the risk of transient bacteria. Prepackaged cleansing products can help decrease potential contamination as well as address nosocomial infections triggered by the use of the hospital water system responsible for aerosolization of bacteria.



Powered Air Purifying Respirators (PAPRs) offer 150 percent more protection than N95 masks for SARS, TB, avian flu and other airborne infections, without the OSHA-required fit-testing. The Bullard PA20 Powered Air Purifying Respirator (PAPR) with a 20LFL loose-fitting facepiece provides superior protection, comfort, and value for healthcare professionals. Advantages of the Bullard PA20 include superior air flow for better protection and cooling, plus a 10-hour battery that features a low-battery alarm and NiMH battery technology for quick and easy charging.


TSI Inc.

TSI Inc. offers the PortaCount® Plus Respirator Fit Tester and N95-Companion™ with which to quantitatively fit-test series-95 disposable respirators. The OSHA-compliant test replaces subjective and tedious Bitrex and saccharin methods. Included software automates fit testing and maintains records. New features allow users to access databases from multiple networked installations, backup/restore databases and print fit test cards with optional printer.


Bio-Medical Devices Intl.

Bio-Medical Devices Intl. offers the MAXAIR® Respiratory Protection System for the healthcare market. This NIOSH-approved, hose-free powered air purifying respirator (PAPR) is an alternative to current respirators that require fit-testing. Air is channeled through the helmet by the motor and drawn through the HEPA filter, down over the headpiece toward the front of the face. MAXAIR is designed to shield workers from splashes as well as airborne and bloodborne pathogens, yet it facilitates greater freedom of movement. Compared to N95/N100 masks, MAXAIR offers optimum protection that exceeds NIOSH standards, as well as comfort because the PAPR allows space for wearer’s facial hair and glasses. MAXAIR also provides ease of use, simplified decontamination, and lower disposable costs, plus unobstructed wide-angle view and one-person donning and doffing.


TVI Corporation

TVI Corporation designs, manufactures, and supplies decontamination, command and control, airborne infection isolation and mobile surge capacity shelters, systems and accessories. TVI offers a comprehensive line of infection control-related shelters than can be used by hospitals in a construction, pandemic, catastrophe or bioterrorism event. The product line includes framed anterooms, bio-isolation shelter retrofitting kits, negative-pressure isolation systems, fixed-room conversion filtration systems, outdoor infection control/isolation shelters, decontamination shelters, inflatable surge shelters, and articulating-frame surge shelters.


Biological Controls Inc.

Biological Controls designs and manufactures FDA-compliant airborne infection control equipment for healthcare facilities, including a full line of products for creating negative- and positive-pressure isolation rooms, air pressure monitoring , HEPA filtered and germicidal UV for creating in-room purification and air changes.


Liquitech Inc.

LiquiTech’s disinfection systems are designed to eliminate the threat of pathogens in water, such as Legionella, Listeria, Salmonella, E. coli, Pseudomonas, M. Avium and Staphylococcus. Preventing these kinds of waterborne, healthcare-acquired infections can save healthcare facilities thousands of dollars in infection-related care, as well as improve the quality of care and ensure a safer environment and a better experience for patients.