From Construction to Infection

9 September 2007 (Last Updated September 9th, 2007 18:30)

Recent studies have shown that construction presents a significant danger to immune-compromised patients. Gordon D Burrill, president of Teegor Consulting, Inc, looks at the evidence and asks what is being done to protect the vulnerable.

According to the World Alliance for Patient Safety, over 1.4 million people worldwide are suffering at any given time from infections acquired in hospitals. Of such significance is this concern that there are initiatives across the globe to address these challenges.

The WHO initiated the 'Clean Care is Safer Care' initiative in 2005 and issued this campaign as a Global Patient Safety Challenge 2005–06. Similar programmes exist at a national level throughout developed countries.

Even though there are many causes for these infections, construction work in healthcare buildings is emerging as a known risk for immuno-suppressed occupants of our healthcare buildings. In fact, the Centers for Disease Control and Prevention (CDC), a division of the Department of Health and Human Services in the US now lists one of the transmission methods for aspergillosis: "Nosocomial infection may be associated with dust exposure during building renovation or construction," it says.

"Construction work in healthcare buildings is emerging as a known risk for immuno-suppressed occupants of our healthcare buildings."

Although these challenges are nothing new, trends to control the potential spread of infectious agents during construction are starting to emerge. Reports linking fungal spores attached to construction dust with negative patient outcomes go back to 1978, while reports linking bacterial influences have been reported even prior to this.

However, it was not until studies and reports in the late 1980s and 1990s that healthcare organisations started to take note of what is now known as a significant source of infection. In fact, a recent study uses the following phrase: "Construction, a well-known environmental risk factor for invasive aspergillosis…" in referencing work by Hajjeh and Warnock.

Knowledge in this field simply continues to grow as we improve our understanding of sources and their connection to the patients. In another recent study by Cooley et al, the authors suggest that "shifts in epidemiology of colonising organisms in this patient group during hospital construction may be worthy of closer attention and surveillance."

Further, the authors go on to theorise around the coincidence of the peaks of scedosporium prolificans isolates with nearby construction work in the hospital. This statement clearly indicates that construction areas are being linked to healthcare-associated infections.

CONTROLLING POTENTIAL AIRBORNE PATHOGENS

As much of the literature indicates, the most significant source of healthcare-associated infections related to construction arises as a result of the dust that is raised during construction and demolition. Attached to that dust are tiny fungal spores of many different species, but of most significance are the spores of the Aspergillus species and particularly A. fumigatus.

These fungi are naturally occurring, ubiquitous and a necessary part of biological eco systems. One of the key components of decomposition of organic matter, they help to turn your banana peel back into fertile soil.

Although these fungi are naturally occurring, they can be problematic for people in healthcare buildings with immune system challenges. For healthy humans, our body's immune system recognises these fungi and several others as being foreign to the body, and expels them in very natural ways. If, however, a human's immune system is not functioning properly (either as a result of an underlying condition or as a result of medical treatment) then the fungi are not as readily expelled.

In those cases where the fungi are not expelled from the body, they are said to colonise and actually start to grow. This is not unlike mould growths that might occur if paper products have been stored in a damp and dusty location.

In immune-suppressed patients, these infections are often fatal. Depending on the governing body, the death rate for immune-compromised patients that become colonised with aspergillus or develop invasive aspergillosis, is said to be between 40% and 90%. This is despite its recognition and treatment.

By far the best approach to dealing with this challenge is to contain the airborne dust which contains fungal spores before it reaches those immune-compromised building occupants.

ENGINEERED SYSTEMS

Although airborne fungal particles are certainly a major concern, construction projects have been shown to have other negative impacts on the building's engineered systems. In order to accomplish many projects, the engineered systems (water, heating, air conditioning, electrics and so on) must be interrupted at some point. This causes stresses within these systems.

Such actions as recharging a water system that has been drained to accomplish work allows for a disruption of the typical water stream, including the biofilm and debris that may have been present in the pipes for some time.

Another impact that can happen during construction is that air-handling duct work is modified during the construction work or perhaps simply shut down to accomplish the work. When the system is repressurised, there is a nearly instantaneous change in pressure within the duct work, which will dislodge fungal spore-laden dust and allow it to become airborne.

During construction work in healthcare facilities, workers must take care to ensure that their work has the least amount of impact possible on the building's engineered systems.

IMPACT ON PRACTICE

What does all this research mean to the caregivers who are trying to protect patients in their healthcare buildings?

It really means a change in culture with respect to construction work in healthcare. It is no longer 'business as usual' for builders and maintenance workers in healthcare buildings.

WHO's 2002 Prevention of Hospital-acquired Infections, A Practical Guide talks about planning for construction or renovation. Chapter eight of that report talks about establishing planning teams in hospital construction projects and that these teams should have infection-control skills. This information appears to be the beginnings of a renaissance of sorts within the healthcare construction industry.

"The death rate for immune-compromised patients that become colonised with aspergillus or develop invasive aspergillosis is said to be between 40% and 90%."

This cultural shift is really starting to take shape in North America with the introduction of a couple of important documents. The design guideline document that is used by the majority of states within the US has particular requirements when preparing for construction projects in healthcare buildings.

The 2006 edition of the FGI/ AIA Guidelines builds on their previous information to continue the growth of this cultural shift. Chapter 1.5, paragraph two outlines several specific requirements, detailed as ‘Infection Control Risk Assessment Process’.

In addition, a Canadian standard is shaping new techniques to be used for both new and existing construction in that country. The Canadian standard was first released in 2003, and since then there has been a significant shift in the construction culture in healthcare buildings in that country. A new edition of the Canadian standard is expected in 2007 and will continue to shape the cultural shift which has already begun. This entire standard is dedicated to reducing the risk associated with construction, renovation and maintenance work for immune-compromised building occupants.

In cases in which the author has been involved, healthcare organisations are using risk-management techniques relative to their construction projects. Once healthcare organisations have established criteria for determining building occupant risk groups and construction activity types, a tool such as a risk analysis matrix is used to establish appropriate measures to protect the building’s occupants.

A new term introduced in the 2006 FGI/AIA Guidelines is 'infection control risk mitigation recommendations (ICRMR)'. This is a powerful term outlining the healthcare organisation's requirements for construction teams to reduce the risks associated with the transmission of airborne or waterborne fungi or bacteria.

These ICRMRs are now being included in construction documents for healthcare construction in the US. Construction and maintenance teams in healthcare organisations throughout North America have become creative in the modification of their construction techniques to continue to protect the immune-compromised building occupants.

Unfortunately, there is no one-size-fits-all solution to the challenges created by the presence of fungi and bacteria in our healthcare buildings. Each project (from small maintenance tasks to large new building construction) must be evaluated for its risk, and appropriate steps taken to mitigate those risks.

The literature and history have shown us that there is a challenge associated with fungi and bacteria in construction work in healthcare buildings. The construction industry in North America is rising to meet this challenge by rethinking virtually everything it does.

If we work in the healthcare field, we must always be mindful of the phrase often attributed to Hippocrates: 'First, do no harm'. Let us all ensure that works sites in our healthcare facilities live up to that maxim.