Throughout history, pandemics—plague, small pox, and measles, among others—have caused millions of deaths. These were largely eradicated in developed countries by the 20th century, but strains such as HIV and now Ebola are continuing to kill thousands throughout the world, specifically affecting underdeveloped nations with weak healthcare systems. Ease of global travel has now increased exposure to the most virulent of these diseases, and many are starting to creep back into North America and Europe.

Though infection control has become a hot topic in healthcare facility design, the effort is focused on healthcare-associated infections (HAIs) such as MRSA (methicillin-resistant Staphylococcus aureus) or C diff (Clostridium difficile). Though insidious, these infections can be controlled through routine good practice and supportive design. However, that’s not the case for highly infectious diseases. Epidemics, such as the SARS outbreak in Singapore and Canada in 2002 or the H1N1 flu virus of 2009, required early detection, isolation, and containment, and subsequently raised the awareness of health officials that a more diligent approach needed to be developed.

One solution was the creation of biocontainment patient care units, of which there are four in the United States that house a total of 25 beds. These units were funded by the federal government to isolate patients who have a highly infectious disease that could cause an epidemic, or for victims of bioterrorism. The largest of these units is at University of Nebraska Medical Center in Omaha, Neb., which contains 10 beds. The others are Emory University Hospital in Atlanta (two beds), National Institutes of Health (NIH) in Washington, D.C. (seven beds), and Rocky Mountain Laboratories (St. Patrick Hospital) in Missoula, Mont. (six beds).

The recent appearance of the Ebola virus in the U.S. has sparked political action in several states to initiate development of this caliber of facility. Recent announcements include a new space at North Shore-LIJ Health System in New York, and the Methodist Health System is converting an ICU wing at its Campus for Continuing Care in Richardson, Texas, where it will provide decontamination, laboratory equipment, and other dedicated personnel for IT and biomedical support to meet biocontainment standards.

In 2009, the European Network of Infectious Diseases (EUNID), a European Commission co-funded network of experts in the management of highly infectious diseases, created recommendations for high-level isolation units (HLIU). EUNID defines a HLIU as a “healthcare facility specifically designed to provide safe, secure, high-quality, and appropriate care, with optimal infection containment and infection prevention and control procedures, for … a small number of patients who have, or who may have, a highly infectious disease.”

Though personnel undergo extensive training in order to handle such virulent diseases, facility design must support these best practices. While there’s no current recommendation for a broad expansion of services, it’s conceivable that in the future every major city in the U.S. (or at least cities with a major international airport) may have an inpatient unit that’s designed to handle highly infectious diseases, if necessary.

There are a number of design directives that can be followed to create a permanent HLIU or a unit that can be flexed to isolate highly infectious cases based on the current Centers for Disease Control and Prevention (CDC) and EUNID guidelines. What follows are just a few; for a more comprehensive list, go to

Design breakdown
Emergency department
: Since the ED is the first portal to a hospital, it’s important to separate and triage suspected infectious patients outside the main area to avoid compromising the entire operation. Ideally, this would be a permanent, separate waiting area with negative airflow and a dedicated hazardous exhaust system. More likely, though, the answer might be an adjacent open space or parking lot that allows for tents or temporary mobile units with access to all utilities (HVAC, power, medical gases) until the risk is mitigated.

Location: The preferred location for an HLIU is a tertiary referral hospital, either in a separate building on the same site or as a separate unit within the hospital with a secure, controllable entrance/exit route. It should be designed internally so that movement of clean and contaminated staff, patients, and equipment through the unit ensures segregation of clean and dirty materials. In more temporary situations, physical barriers (e.g., plastic enclosures) can be used where necessary, along with visible signage, to separate distinct areas and ensure a one-way flow of care moving from clean areas (where personal protective equipment [PPE] is donned and unused equipment is stored) to the patient room and to the PPE removal area (area where PPE is removed and discarded).

Decontamination: Solid waste generated in an HLIU requires decontamination before disposal. Most HLIUs achieve this by autoclaving, though is the process is time consuming and energy inefficient. Integral autoclave facilities or safe access to pre-identified, dedicated autoclave facilities is required, unless a waste management contractor with special hazardous material training is available and willing to remove the large amount of infectious waste. An integral  Biosafety Level 3 ( BSL3) or equivalent laboratory, or access to one in close proximity on the same campus, is ideal. A sealable area for the decontamination of large equipment and a designated area for handling and packaging clinical waste are required.

Storage: Adequate storage space for large equipment, supplies of PPE, pharmaceuticals, and clinical supplies is a must. Also, there must be an area for the temporary safe-keeping of deceased patients, large enough to contain and decontaminate trolleys, sealable coffins, and other mortuary equipment.

Ventilation: Although most highly infectious diseases aren’t primarily airborne, there’s still risk in poorly ventilated environments. Therefore, the World Health Organization suggests that with airborne isolation precautions, the HLIU ventilation system should be independent of the other building heating, ventilation, and air conditioning systems. The HLIU must be pressurized so that air flows from the cleanest to the most contaminated areas, with the patient room under negative air pressure relative to adjacent spaces. Air from the HLIU is not recirculated (12-20 air changes per hour) and all exhaust air is vented to the outside of the building at a distance from the building that minimizes the risk of contamination to occupants inside and in the community. HEPA (high-efficiency particulate air) filtration of exhausted air is preferable and obligatory if there’s any possible risk of human exposure to exhaust air re-entering the space.

Laboratory: The EUNID recommends that all Ebola samples be handled in a BSL 3 lab. With other infectious diseases, a hospital may choose to p
rocess samples outside of the main lab due to its proximity to the infected patient, eliminating the threat of cross contamination.

Staff: There should be a separate staff lounge and office area contiguous to the unit with changing and shower facilities, including a decontamination shower. Patient monitoring requires a large amount of staff rotation and preparation, so these areas are much larger than conventional critical care units.

Family: Since the family can’t remain with the patient and they’re in an extremely stressful situation, special waiting areas should be developed with amenities that provide comfort.

Finishes: Units need to be constructed for ease of cleaning and decontamination (seamless floors and walls, solid horizontal surfaces) and be as airtight as possible (monolithic ceilings, sealed doors and windows) with other design features that enhance the ventilation system, such as an interlocking door system with a clinician-controlled override function.

Communication: A high-quality communication system, including an emergency alarm, will summon clinical help when needed. Family-to-patient communication should also be considered to improve their experience.

Patient room: The room needs to be sized the same or larger than a typical private critical-care patient room, large enough to accommodate specialist equipment (mechanical ventilator, hemofiltration machine, monitoring equipment) and allow free movement of staff wearing bulky PPE. Each room needs a private bathroom (toilet, handwashing sink, and shower). Other details include a room door with an automatic closer, a hands-free lavatory, and a view window for observation from an anteroom.

Anteroom: This is an area outside the patient room (in a temporary setting, such as a nearby patient room or a marked area in the hallway) where clean PPE is stored and where healthcare workers can don PPE before entering the patient room. If waste passes through this area, it must be properly contained, but preferably it’s taken out via a separate route. The anteroom must also be large enough to store clinical supplies (intravenous fluids and tubing, syringes, dressings, specimen containers) and also house a hands-free lavatory.

PPE removal area: This space should be close to the patient room and separate from the clean area, a place where healthcare workers leaving the patient room can take off and discard their PPE. This space must be easily disinfected and provide an area where workers can sit. Leak-proof infectious waste containers for discarding used PPE are required. This area should be adequate for packaging clinical specimens and for decontaminating outer specimen containers, too.
Emergency response
Highly infectious diseases require extraordinary clinical diligence that can’t be supported by conventional critical care isolation room or unit design, such as those described in the current Facility Guidelines Institute (FGI) guidelines, which aren’t intended to protect against such virulent diseases. In fact, comingling of these patients within a hospital’s existing units is highly undesirable.

If in the future there’s a significant increase in highly infectious disease cases, then freestanding facilities or units in academic, tertiary hospitals may become a norm. Likewise, hospitals without these facilities should develop contingency plans to hold and isolate individual patients until they can be transferred in a safe manner, or to handle mass casualties. Criteria for the safe handling of Ebola and other highly infectious patients are evolving quickly, and the healthcare design community will need to respond with best practices in subsequent facility design.


Sheila F. Cahnman AIA, ACHA, LEED AP, is founding principal of JumpGarden Consulting LLC. She can be reached at
Bannister, B., Puro, V., Fusco F.,  Heptonstall, J. , Ippolito, G. for the EUNID Working Group, Framework for the design and operation of high-level isolation units: consensus of the European Network of Infectious Diseases, The Lancet Infectious Diseases, Volume 9, Issue 1, Pages 45 – 56, January 2009.

Center for Disease Control, Guidance on Personal Protective Equipment To Be Used by Healthcare Workers During Management of Patients with Ebola Virus Disease in U.S. Hospitals, Including Procedures for Putting On (Donning) and Removing (Doffing),, October 20, 2014.

Courage, K.H., Inside the 4 Biocontainment Hospitals That are Stopping Ebola, Scientific American,, October 24, 2014

North Shore LIJ Health System ,To Address Future Infectious Disease Outbreaks, North Shore-LIJ Announces Plans to Build Bio-Containment Unit,, October 23, 2014.


For more about infection diseases design, read “Healthcare-associated Infections Keep Industry On High Alert.”