Infection Control Today - 08/2004: Splish Splash

Splish Splash
What’s Taking a Bath in Your Hospital’s Water System?

By John Roark

Legionella pneumophila, Aspergillus fumigatus, and Clostridium difficile are on the most-wanted list of airborne and waterborne pathogens. Will we ever really have them contained?

Every healthcare facility is rife with ideal conditions for any number of airborne and waterborne pathogens. These bugs set up shop where you would expect to find them, and are stealthy enough to hide where they may not be detected — until the immuno-compromised patient succumbs to infection.

The Joint Commission on Accreditation of Healthcare Organization (JCAHO)’s 2005 Surveillance, Prevention and Control of Infection standards state that the “prevention of healthcare-associated infections (HAIs) represents one of the major safety initiatives an organization can undertake, making the effective evaluation and possible redesign of existing infection prevention and control programs a priority.”

The Centers for Disease Control and Prevention (CDC) estimates that each year, approximately 2 million patients admitted to acute-care hospitals in the United States acquire infections that were not related to the condition for which they were hospitalized. These infections result in approximately 90,000 deaths, and add between $4.5 to $5.7 billion per year to patient-care costs.¹

Aspergillus, tuberculosis, SARS, gram negative bacteria and biological agents related to bioterrorism are part of the unending awareness in the fight against airborne pathogens. The CDC’s Guidelines for Infection Control in Health-Care Facilities state that “once these materials are brought indoors into a health-care facility by any of a number of vehicles (e.g., people, air currents, water, construction materials and equipment), the attendant microorganisms can proliferate in various indoor ecological niches and, if subsequently disbursed into the air, serve as a source for airborne health-care-associated infections.”²

“As you look at hospitals, the focus needs to be placed on looking at the risks of where these airborne and waterborne pathogens can enter and reside in healthcare systems,” says Terri Rearick, RN, BS, CIC, administrator of safety services at Children’s Memorial Hospital in Chicago. “Human reservoirs come to mind first. The challenge is to identify that these reservoirs exist since people may be carrying airborne diseases as they enter the healthcare system. The buildings of healthcare systems are organized in such a way that the challenges of potential reservoirs of airborne organisms also exist in our ventilation systems, our water supplies and in our care environments.”

The scrutiny of hospital design and the emphasis on location of air intake, ventilation flow and exhaust play a vital role in containing these pathogens. It all harkens back to tuberculosis, says Corinne Connor, RN, BSN, corporate manager for infection prevention and control, also at Children’s Memorial Hospital. “Back when tuberculosis was an even more endemic disease in this country than it is now, managing the flow of patients was one of the things that brought to the forefront the idea of how you get people into and out of your institution, what is the best way to capture their symptoms early and make sure they don’t move forward through the rest of the facility. I think the advent of negative air, and the whole idea of venting some areas directly to the outside with filters to keep from re-circulating the bacteria also stems from the initial studies of tuberculosis — how we treat this and how we prevent transmission of it.”

In years past, hospitals had infectious disease units with concentrated populations of patients with suspected or diagnosed infections that required isolation. “The hospitals didn’t have the design of today’s hospitals in which the negative air pressure rooms, meant to contain airborne contagious diseases, are scattered two or three on a unit,” explains Rearick. “This concentrated design of one given geographic setting within a hospital allowed for all patients who needed negative air pressure isolation, or other modified forms of isolation, to be placed in that one unit. This design served its purpose and may be reconsidered in the future depending on the evolution of highly contagious communicable diseases.”

In TB’s heyday, hospitals had infectious disease units focused in one given geographic area. “I think it served the need at the time, since there were more diseases that required intense isolation,” says Rearick. “The availability and use of vaccines for such agents as measles, mumps, rubella, diphtheria, tetanus, pertussis, varicella, and other infectious agents have altered the need for concentrated areas of negative air pressure rooms.

There was a purpose for the design, but, as years of vaccine use have gone by, the needs have changed. Once again, people are starting to look at alternate designs carefully as they design healthcare facilities with the onset of SARS and other diseases that have airborne characteristics.”

“There are so many other diseases that have airborne transmission characteristics that I think people are trying to prepare for the possibility of needing to react to them in the future if they become endemic; if not epidemic, again,” says Connor. “Where there’s an occasional patient who comes into your facility with TB, we’re not going to be again dealing with diseases where maybe 10 or 15 people will be coming in with the same type of disease. We will need to go back many decades in healthcare to revisit that mind set.”

While some institutions are considering building completely separate infectious disease hospitals, others facilities consider the feasibility of constructing infectious disease wards.

“Hospital Resource and Services Administration (HRSA) has requested that hospitals develop a plan to isolate 500 patients per million population,” says Andrew Streifel, MPH, a hospital environment specialist at the University of Minnesota. “According to the Office of Emergency Preparedness, designated hospitals should have 10 infectious disease beds per hospital and be able to handle pediatric or adult populations. This is something that is pretty much a nationwide issue.”

CDC guidelines state that environmental disturbances caused by construction and/or renovation and repair activities in and near healthcare facilities markedly increase the airborne aspergillus spore counts in indoor air and increase the risk of nosocomial infection among high-risk patients.³

“When you take old hospital buildings and start tearing into them, you’re going to uncover a lot of different critters that have been there forever and ever,” says John James, PhD, MPH, a microbial epidemiologist at Children’s Hospital of Denver. “In most hospitals in America, there is constant construction and remodeling, which causes problems when areas are opened and microbes are released, and you have to create containment systems. We have a very elaborate system of containment here — you don’t drive a nail into the wall without my permission.

I go and see what’s happening for any kind of remodeling or construction that goes on. You have to have a building permit and an infection control permit to do anything.”

James inspects sites and examines barriers; for big projects, he is involved from the architectural stage through completion. Every step of the way, he says, he finds problems. “When you go into these old areas, you find evidence of mold growth and water leaks from 50 years ago. If you didn’t contain them, fungal spores and other microbes would be floating around, moving down hallways and getting to immuno-compromised patients.

“If you have dry building envelopes, and internal walls where there has never been water, you don’t have much to worry about,” continues James, “but when you get water intrusion, the moisture plus the organic materials in the dust act as nutrient for fungi, and you get growth. As long as you can keep it dry, you don’t have any problem. But you can’t keep any building completely dry. You get small leaks in water pipes, or roof leaks, windows leak and water intrudes into the wall cavity.”

Methicillin-resistant Staphylococcus aureus (MRSA) survives in the environment for weeks to months, says James. “It’s in dust. If you want to find MRSA, C. difficile or Vancomycinresistant Enterococci (VRE) in a hospital, you go to the corner of the room. The air movement concentrates the dust in those corners, and the environmental services people have a hard time cleaning out the little corners. That’s doesn’t mean that that’s going to be a cause of infection for somebody, but you want to be as clean as you can. Dust control is very important in the hospital environment.”

The legal liability related to indoor air quality in healthcare settings is expansive, and the risk of construction-related infection has gained some media attention. In what ways are healthcare facilities vulnerable to liability?

“A lot of it has to do with water damage and whether or not they can provide performance criteria for their facility,” says Streifel. “We would like to build our facilities mold-free, as much as we can, but we know good and well that water damage occurs during construction — you create a condition wherein if the climate is correct, you could have lots of mold damage. If the owner accepts that building in that condition and they put immuno-compromised patients in there, you’re going to have a problem.”

In September 1992, a 55-year-old man underwent herniated disc surgery in a Massachusetts hospital. During the procedure, an airborne fungus contaminated the surgical site, which resulted in a disc space infection, complications of which lasted for nearly six months before doctors determined that the fungus had caused the infection. The plaintiff brought claims against a general contractor and sheet metal contractor who installed an air handling system in the operating room, as well as claims against the environmental testing company that evaluated the OR suite after installation of the new air system. In addition, he filed claims against the hospital, the chairperson of the infection control committee and the infection control practitioner. The case settled after more than four years of litigation. The contractors settled for a total of $117,000; the environmental testing company settled for a total of $150,000, and the medical defendants settled for a total of $450,000.⁴

“What the problem was for that facility is they discovered the mold,” says Streifel, who served as an expert witness on the case. “They shut the fan down for several weeks during construction; they decided that they were going to test the environment to see that it was appropriate for doing orthopedic surgery. They tested the air and found 650 colony-forming units of aspergillus fumigatus per cubic meter of air — it was the highest number I have ever seen inside of a hospital.

“We’ve got hospitals right now in this country that are 18 to 20 months past occupancy because the construction was so shoddy that they allowed water to come in around the flashing, the workmanship was very poor, scuppers failed, they drilled holes right through the stucco, brought water into the inside of the building,” continues Streifel. “That intensive care unit will not be occupied by the clinical staff because the risk is too great. Who gets blamed for that?”

Pseudomonas aeruginosa accounts for 10 percent to 20 percent of nosocomial infections, and about 1,400 deaths per year, says Matthew Freije, president of HC Information Resources, a firm that offers publications, consulting, and seminars pertaining to legionella and other waterborne pathogens. “Those 1,400 deaths per year are just from nosocomial pneumonia caused by Pseudomonas aeruginosa, the organism causes other illness also.”

Legionella and pseudomonas pose the most consistent threat in the healthcare setting, says Freije, with honorable mention to the mycobacterium species. “Legionella has been studied far more than other waterborne pathogens, so we have more data on which to base specific preventative measures,” he says. “Also, measures that control legionella will control a lot of the others as well.”

Plumbing systems provide a hospitable habitat for waterborne pathogens, and cooling towers are a potential source for contamination, especially for legionella. “It is thought that the domestic water systems account for more nosocomial infections than cooling towers,” says Freije, but both need to be maintained to minimize risk. “Patients who are immunocompromised because of underlying illness or certain medications or treatment are at highest risk,” he adds.

The first step in prevention is making the decision to proactively try and control the bugs. “That’s not as obvious as it might sound, because many hospitals — probably most — are still in a reactive mode,” says Freije. “The CDC’s new guidelines recommend maintaining water systems to minimize legionella, which is a significant addition to its previous documents.

“According to the CDC, about 90 percent of Legionnaire’s disease cases go undetected,” he continues. “To improve patient care it’s necessary to minimize legionella in the water systems. There are numerous preventive measures for domestic water systems and cooling towers pertaining to design, installation, operation and maintenance. The good thing is that most of the preventive measures are not costly, and provide additional benefits such as increased efficiency or longer equipment life.

“Legionnaires prevention is a pretty good bargain, actually, because risk can be significantly reduced fairly inexpensively. It’s not like asbestos, where you might spend millions of dollars to achieve a relatively small increment of risk reduction.

Moreover, taking these preventive measures for legionella not only improves patient care, but is also the best way to avoid a lawsuit, or to defend a lawsuit of a case if disease occurs despite the preventive efforts. “Many attorneys do not realize this,” continues Freije. “The old way of thinking was that a head-in-the-sand approach to Legionnaires’ disease was the best legal defense, but attorneys who have been involved in Legionnaire’s litigation know better.”

Beyond cooling towers and plumbing systems, specific items such as decorative fountains, respiratory care equipment, hydrotherapy tanks and pools, ice machines and storage chests can serve as sources of pathogens. “Any equipment that’s attached to the water system needs to be considered,” says Freije. “It’s best to minimize equipment attached to the water system.”

James cites an instance when he found waterborne Aspergillus fumigatus in the p-trap of a hospital sink. “The trap had been recently snaked by a plumber,” he recalls. “I didn’t know this work had been done, and came right behind the plumber and did some microbiological sampling for fungi. All of a sudden I grew more Aspergillus fumigatus than I’d ever seen in 12 years of sampling. I couldn’t figure out why I was getting so much at this one site, but in no other. I did some fact checking and found out this event had occurred; I went down into that trap and was able to find Aspergillus fumigatus. In a unit full of immunocompromised patients, this is not good to have. We made sure these traps were cleaned and that we flushed them more frequently.”

In yet another example of the waterborne pathogen shell game, James recounts the case of a technician who would start exhibiting respiratory distress an hour after starting work every morning. Upon investigation, James discovered an energy management policy wherein the air conditioning system was shut down every night at 10 p.m., meaning no air supply, neither heat nor cooling, reached the lab each night — but the exhaust was kept on. “That made the lab strongly negative,” he says. The culprit proved to be a flooding floor drain, which was becoming positive and blowing pathogens into the lab. “When she came in every morning, she was inhaling everything that was coming out of the floor drain all night long. We found out through some immunologic testing that she was allergic to only one fungus: Aspergillus fumigatus. We sent a serum sample off to Johns Hopkins, and found out she had precipitating antibody to Aspergillus fumigatus, which is an indication of hypersensitivity pneumonitis.

“We closed the circle, sealed the floor drain, and symptomotalogy went away. You never know what is lurking in these remote places.”

Waiting to Inhale: The Fit-Test Conundrum

By John Roark

On April 29, 2004, representatives from the Association for Professionals in Infection Control and Epidemiology (APIC) and the American Hospital Association (AHA) met with Occupational Safety and Health Administration (OSHA) administrator John Henshaw and other OSHA officials, regarding the agency’s recent decision to include exposure to patients with potentially infectious TB under the General Industry Respiratory Protection Standard.

The push/pull debate between OSHA’s stance on fit testing and hospitals’ view of the impending edict as time consuming, expensive and unfeasible rages on.

“I would like to have some science-based evidence that clearly indicates that respirators do indeed make a difference in interrupting disease transmission,” says Terri Rearick, RN, BS, CIC, administrator, safety services at Children’s Memorial Hospital in Chicago. “We still haven’t seen the science behind the need for and use of respirators for biologic agents. We may learn more if SARS presents itself again and challenges us to better understand the relationship. The cost of respirator fit testing and routine refit testing to healthcare is potentially staggering. Our healthcare dollars are so precious; we want to make sure that if we are using personal protective equipment that actually interrupts disease transmission and that we are using them in the best manner possible.

“Nothing has really been finalized, so as healthcare workers, we’re all waiting for the other shoe to drop, and to find out exactly what it is that we will be required to do. I think OSHA struggles so much with taking that industrial model and trying to apply it to medicine. It’s just not always a fit.”

Many infection control practitioners are scratching their heads over the issue, waiting for a logical resolution. Henshaw stresses that OSHA’s primary concern is the protection of healthcare workers, and that the agency has no intention of imposing anything that is unnecessary or a waste of resources.

A quick survey of APIC board members revealed what many clinicians have been saying all along: protection of healthcare workers is paramount, but is annual fit testing necessary?

“We want to be sure that personnel are very much aware that they need to wear the masks, and that they wear the proper size, that the proper size is available to them, that they know how to put them on and fit-check them. We have to be really careful that we make sure that our personnel know that. We don’t want to seem that we’re holding back on the OSHA regulations, we just don’t believe in that part of the regulation. We believe that they should be worn, but we don’t think it’s necessary to fit test them for TB.”

“I think fit testing is important when you hire a new employee, and I think it’s important that you do a physical, sit-down conversation with the employee each year after they’ve been fit-tested to make sure what you have on your records is correct: that they have not lost too much weight, had facial surgery. You need to discuss everything with them. I think it’s also good for them to review the procedure for putting on the mask correctly, and making a fit check. It’s important for them to review that every year if they’re not an employee that goes into isolation rooms periodically.”

“The small hospital that I worked at in southern New Mexico actually did fit test its employees every year. They had a good system for it and it worked, but I used to say, what the heck are we doing here? Why are we bothering? What are we really accomplishing? What’s the return here? I’m not sure there is one.”