SPECTRE Blog Series Part 5: Key Elements and Considerations of a Biocontainment Unit

Biocontainment Units (BCUs) are facilities designed to care for patients affected by high-consequence infectious diseases such as ebolaviruses and other viral hemorrhagic fevers, smallpox, severe acute respiratory syndrome coronavirus (SARS), and other emerging pathogens. BCUs are staffed by healthcare workers who are trained in high-level isolation precautions, including working in specially designed personal protective equipment (PPE). When not actively used as a space to care for a patient with a high-consequence infectious disease, BCUs can be used for routine patient care or serve as a site for research or training. Below is one example layout of a BCU from The Johns Hopkins Health System. Biocontainment unit layouts and specifications will vary across facilities and respective health systems - each institution needs an environment tailored to its specific requirements and circumstances.

Figure 1. General layout of biocontainment unit: Patient rooms and the laboratory (if applicable) have dedicated space for donning and doffing personal protective equipment. This allows unidirectional flow to reduce the risk of cross-contamination. Green indicates clean space; red indicates contaminated space; yellow indicates doffing rooms. (1) Off-unit area with dedicated elevators, locker room, changing area, and lounge for staff; (2) clean entry and exit space for staff; (3) nurse station; (4) shared donning room for laboratory and Patient Room 3; (5) laboratory; (6) doffing room for laboratory; (7) Patient Room 3; (8) doffing room for Patient Room 3; (9) shared donning room for Patient Rooms 1 and 2; (10) Patient Room 1 with two intensive care unit headwalls; (11) doffing room for Patient Room 1; (12) Patient Room 2; (13) doffing room for Patient Room 2. (Photo courtesy of The Johns Hopkins Health System Corporation)


Once a patient is placed in a patient room within a BCU, healthcare personnel must move within the BCU carefully and strategically. Ideally, BCUs should allow for a unidirectional flow of providers and materials to reduce the risk of cross-contamination (using a consistent and predetermined pathway for entering and exiting) and have designated spaces for donning and doffing PPE (ex: anterooms provide designated space outside the patient room, between patient room and hallway). A BCU is designed to prevent the spread of infectious material via contact, droplet, and airborne routes. As such, BCUs should have specialized air-handling systems that ensure negative pressure airflow throughout the entire unit, with negative pressure increasing as one travels closer to a patient room. A BCU should have an air pressure monitoring system within view throughout the unit for staff to refer to. All personnel must undergo training to effectively interpret the information relayed by the system, including data on differential pressure, temperature, and air changes. This knowledge is crucial for staff to be aware of the current direction of air flow at any given time. Patient rooms in a BCU should be capable of providing most care without removing patients from containment. Additionally, these rooms should provide ample space to accommodate necessary equipment. Some equipment may be required to remain in the patient’s room until discharge in order for proper decontamination. Other times, equipment may be covered during use to prevent contamination and stored in the anteroom between uses.

It is highly advantageous for BCUs to be self-sufficient. This means that all essential systems within the BCU, including air handling, air gases, and electrical systems, are entirely separate from the rest of the hospital. Each mechanical system should be exclusive to the unit, and there should be backup systems in place so that the ability to care for someone or maintain safety within the unit is never lost. Further, it is highly advantageous for BCUs to have an on-site laboratory that eliminates the need to send samples to the main hospital laboratory and reduces the risk of exposure to other staff within the broader healthcare system. The laboratory may not always be located within the same unit; samples might be analyzed in a different area down the hall or even in the patient's room. Designing BCUs involves careful thought, consideration, and attention to detail to effectively incorporate best practices in biocontainment and infection control with unique features that enhance patient and provider safety. For example, selecting non-porous materials for flooring, walls, ceilings, and electrical outlets, including paint, will facilitate thorough decontamination. Several important concepts should be taken into consideration during the design and construction process as summarized below.


Key Features and Considerations of a BCU
Secure entry and exit points: unidirectional flow of providers and materials through the unit can minimize the risk of cross-contamination
Adequate space for donning and doffing PPE: dedicated spaces for donning and doffing PPE such as anterooms are likely to improve health care worker safety
Onsite laboratory: an onsite laboratory minimizes the need to send infectious specimens off the unit
Advanced air-handling system for contact, droplet, and airborne transmission
Highly trained nurse and clinician provider team
Critical care capabilities in each room
Pass-through autoclaves for waste management: an onsite waste management system improves safety and reduces cost

Klarissa Garza is a 2ndyear Master of Public Health – Bioethics graduate student at the University of Texas Medical Branch School of Public and Population Health. She is also a Research Associate in the Neurology Lab on campus studying Alzheimer’s Disease and plans to go to medical school after completing her MPH. In her free time, she enjoys being outdoors, singing and playing the guitar and violin.








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