Taking Control of Airborne and Waterborne Diseases
By John Roark
Controlling the threat to both patients and staff is something all healthcare professionals must contend with. While preventing the threat of infection to patients is critical, protecting staff is also crucial.
The presence of pathogens within healthcare facilities is a given. Nosocomial infections occur in approximately 5 percent of all U.S. hospital patients, which translates to as many as 2 million patients annually. Estimates of the cost of nosocomial infections to the healthcare industry have been assessed as high as $3.5 billion. Studies have indicated that one-third of all nosocomial infections can be prevented through effective infection control programs, yet only 6 percent to 9 percent are actually prevented.1
Aspergillus is one of the main concerns in the healthcare setting. Typically associated with construction-induced air pollution within a healthcare facility, infection and pneumonia induced by airborne Aspergillus fungi can prove fatal to immunocompromised patients. "When we first initiate a construction project, we are involved in meetings with the architect and contractors," says Evelyn Cook, director of infection control at North Carolina Baptist Hospital in Winston-Salem. "We look at the blueprints and design in the planning phase, then initiate an infection control risk assessment, identifying key elements, like what services may be disrupted or have to be moved as a result of this activity." Examining the patient population in the area of construction, whether solid wall or plastic protective barriers will suffice, how air handling systems may potentially become contaminated as a result of the construction, and if the water systems will be impacted or disrupted, creating problems with flooding, are all factors that are considered. "Once we look at all of those things, we can make recommendations to the construction team about what must happen before the construction begins," she says.
"We conduct education for the construction workers so they'll understand the ramifications of all of this," Cook continues. "You may typically find Aspergillus above ceiling tiles. Something as simple as removing a ceiling tile becomes an issue, as the Aspergillus can become aerosolized."
"The problem with Aspergillus is that when it becomes invasive, it becomes extremely deadly," says Andrew Streifel, MPH, hospital environment specialist at the University of Minnesota. "We spend hundreds of thousands of dollars trying to change the course of a disease in a patient. Then, to have them die because of an environmental microbe because someone didn't put up a barrier is a problem."
Streifel has assisted more than 150 hospitals worldwide with matters pertaining to indoor air quality and safe patient-care environments. He contends that the main cause of construction-related infection is airborne fungal spores that originate on water-damaged building materials. For example, cellulose-sheathed building material, such as gypsum board, is prone to fungal growth/contamination. When the material is wet for more than 72 hours, the fungi grow and produce spores. The spores become airborne and remain in the air for long periods of time.2
The American Institute of Architects (AIA)'s Guidelines for Design and Construction of Hospitals and Healthcare Facilities 2001-02 provide guidance on construction. Richard Hermans, senior project engineer for the Center for Energy and Environment in Minneapolis, wrote two chapters in the American Society of Heating, Refrigerating and Air-Conditioning Engineers (ASHRAE)'s soon-to-be-published HBAC Design Manual for Healthcare Facilities.
"It's powerful research, and we think it's going to make a big difference in how rooms are designed," he says. "It turns out that this big open cut in a patient has heat, usually warmer than the room. Add to that the fact that all of the operating room lights shining right on that very spot heat that space up. We've modeled that area and estimated that it would be about 100 degrees Fahrenheit. Because of that temperature, there are convective air currents flowing up out of that space. Those currents have a tendency to kick out airborne particles that would otherwise fall into that space by gravity. It's called a 'thermal plume.' Operating ventilation systems, if done wrong, could actually counteract that effect, driving organisms down into the wound. That whole concept is fairly new and will probably become part of the manual," Hermans adds.
A resurgence of tuberculosis has occurred since in the mid- to late-1980s, with the advent of HIV. Patients confirmed with TB, or those who have not been ruled out as having the infection, are placed in an airborne isolation room or respiratory isolation room where airflow is negative rather than positive. "Typically in patient rooms the air will flow from the room out into the hallway, or it will be neutral -- no push to move the air in any particular direction," says Cook. "In a negative pressure room we don't want that to happen because those tuberculosis organisms can remain on air currents for long periods of time. We don't want the air to go out into the hallway, so we suck the air from the hallway into the room, creating a negative pressure. That air is exhausted to the outside of the building."
Streifel says the Guidelines for Environmental Control, due to be issued this month, will become standard in tandem with AIA guidelines. "These will start to become implemented as a standard of care, dealing primarily with the environmental impact of what we expose our patients to from the environment and how we manage that."
Legionella and bacteria such as Pseudomonas love moist environments. Legionella has been associated with moist environments such as cooling towers, shower heads, faucet aerators, endoscopic equipment, such as respiratory therapy equipment that uses water as a reservoir, or sinks that may be too close to patients' beds, especially in the ICU where contaminated or tap water could get splashed. Two types of Legionella usually cause pneumonia, which can be deadly to immunocompromised patients.
But, warns Cook, unless you go out looking for it, you may not be accurately reporting the number of patients that do or don't have Legionella-caused pneumonia. "By chest X-ray or clinical presentation you can't say, 'That patient's pneumonia is caused by Legionella.' Typically you don't go looking for it because most of our pneumonias are related to other bacteria. Unless you have a patient with a pneumonia and you can't identify the causative agent, and there's some reason to suspect Legionella, you won't go out looking for that species or that organism."
Several issues of AORN Journal discuss disinfecting endoscopic equipment in the morning immediately before the first patient of the day. While some healthcare facilities view this practice as unnecessary, others consider it essential to reduce the risk of nosocomial infections caused by waterborne microorganisms. Reports of healthcare facilities storing coiled, wet endoscopes overnight in an automated reprocessor have been published. The British Society of Gastroenterology recommends that even if endoscopes have been cleaned and disinfected at the end of the previous day, disinfecting them again before the first patient of the day, as well as between patient procedures, is important for the prevention of patient infection.
The time and cost associated with disinfecting each endoscope immediately before the first patient of the day can be significant. This practice is likely to be manageable for a small endoscopy unit performing only a few endoscopic procedures per day or per week. But for large endoscopy centers performing dozens of procedures each day, the practice can be problematic.
Guidelines issued by the Society of Gastroenterology Nurses and Associates (SGNA) recommend disinfecting and possibly cleaning endoscopic equipment before the first patient of the day in the following situations:
- When there is confusion or doubt that after its last use the endoscope was cleaned, disinfected, dried and stored properly in accordance with published guidelines;
- When the endoscope is removed from storage and found to be wet or otherwise stored improperly;
- When a significant number of opportunistic microorganisms such as Pseudomonas species or mycrobacteria has been identified in the facility's water, and therefore, the potential exists for microorganisms to recontaminate the endoscope during rinsing.3
Again, Cook cautions that water-testing methodology can be tricky. "You may test the water today you may or may not find Legionella. Routine culturing of the water is not one of the most efficient means of determining if you have a problem. You may find it, but if you culture the city water you may find it. It's a harder issue to deal with." She continues, "The CDC is not really recommending routine culturing of your water unless you have a reason to do that. Their approach is two-tiered. You do certain things is you haven't identified any cases. If you do identify cases there's another approach."
Streifel's view is clear when it comes to the role environmental services personnel play in the prevention of airborne and waterborne disease: "They have to do a good job. Quite frankly, from my own experience, I have found the janitor's closets in many facilities that I have visited to be substandard, and in some instances, even be the source of potentially infectious microbes. In my own institution we had a problem that didn't cause an infection that we know about, but we do know that when the janitor's closets are not well maintained, they can accumulate these fungal spores. Without question, the fungal spores are carried with the cleaning equipment into the patient's rooms. We question the individuals coming in to visit the patients more than we do the cleaning materials. In several institutions where I've done air sampling, I've found the janitor's closets to be a source of fungal contamination."
Cook underscores the importance of set practices for environmental services personnel. "We have written policies and procedures relating to the type of cleaning agents our environmental services people use. Things like hepatitis B viruses and more resistant organisms like methicillin resistant Staphylococcus aureus (MRSA) and vancomycin-resistant enterococcus (VRE) can live longer on inanimate objects. Most other things can be killed fairly easily. We have a hospital-approved product that we use. We have procedures for how often mop water is changed. For instance, when they clean an isolation room, they immediately change their mop water and mop heads. They don't go to another room. They also go through the infection control educational programs just like the rest of our hospital staff."
Streifel warns that the future holds strict repercussions for healthcare institutions that fail to comply with the new guidelines. "The true regulators in the United States are the insurance companies and the lawyers. The lawsuits that are going on out there are costing institutions millions of dollars in litigation costs, covering their butts to show that they did a good job," he says. "Why in the world didn't they do a good job in the first place and tell somebody at $16 an hour to do the job right, rather than hiring a lawyer at $250 an hour to tell them to do the job. That's a waste of resources. The resources are going places that are not favoring the patients that they're taking care of. That will take some time to reverse, because sometimes the executives in the institutions come from the hospitality industry, not from healthcare. They don't have that much healthcare background."
"It's quite unfortunate that there are facilities out there that are backpedaling because of this," he continues. "If anything is on the horizon, it's more lawsuits, because now the standards of care are in place. They have the guidelines to follow, to do it correctly. If they do not choose to do it correctly, then they will have a problem. The first things I ask when I go into an institution is, 'What are your maintenance records like? What are your procedures for doing construction?' Then let me see that you're doing it the way you should be doing it. It's easy enough to put it in black and white, but it's a little bit different to spend the money to do it right. What we're finding is that those institutions that embrace these types of things and do them correctly, in the long run it ends up costing them less money."