Infection control is emerging as a biggest challenge to health services around the world. All hospitals knowingly or unknowingly admit patients with communicable diseases. In recent years, emerging infectious diseases represent an ongoing threat to the health and livelihoods of people everywhere. Over the last few decades, there have been several emerging infectious diseases (EIDs) that have taken the global community by surprise and drawn new attention to EIDs, including HIV, SARS, H1N1, Ebola, Encephalitis (NIPAH Virus), and Now COVID-19 .

For over a century, it has been recommended that patients with infectious diseases should be placed in segregated facilities to prevent the spread of infection. Hospital’s isolation precautions must fulfill following objective:

To separate patients who are likely to be infectious to other persons.
To provide an environment that will allow reduction of the concentration of airborne particles through various engineering methods.
To prevent escape of airborne particles from such rooms into the corridor and other areas of the facility using directional airflow.
To protect patients who are immunocompromised from potential harmful pathogens.

Types of Isolation Rooms

There are two types of isolation rooms: (1) airborne infection isolation (AII) rooms and (2) protective environ- ment (PE) rooms.

Airborne infection isolation (AII)/Negative pressure

isolation refers to the isolation of patients infected with organisms spread via airborne droplet nuclei <5 μm in diameter. These include patients suffering form measles, chickenpox and tuberculosis.

Protective environment (PE)/Positive pressure isolation is a specialized area for patients who have under- gone allogeneic hematopoietic stem cell transplant (HSCT).

Location

The isolation rooms should be located at one end of medical and surgical wards/critical care units/pediatric care units/newborn intensive care units/emergency service areas/also other areas, such as dialysis. Isolation wards for infectious cases to be kept out of routine circulation. The location of the proposed isolation room, such as those near elevator or doorways should be avoided if possible.

Number of beds for isolation beds

About 2.5% of the beds of a large hospital in a special unit would probably be adequate except during periods of unusually high demand.

Space

An isolation room has to provide sufficient space around the bed for equipment and the increased number of personnel involved in emergency care. A room area of about 22 m2 is adequate within an isolation unit.

Adequate number of wash hand basins should be provided within the patient care areas and nursing stations with a view to facilitate hand washing practice.
Separate arrangements for garbage and infectious waste removal from wards and departments in the form of separate staircases and lifts.
Gasketing should be provided at the sides and top of the door, and at ceiling and wall penetrations, such as those around medical and electrical outlets.

Bed Management

Bed centers should be at least 3.6 m apart. Spacing must take account of access to equipment around the bed and access for staff to hand-wash facilities.
Minimum possible number of beds2-4 should be kept in a cohort as to prevent chances of cross-infection.
Design, accessibility and space in patient areas all contribute to ease of cleaning and maintenance.
Provision of permanent screens between bed spaces

General Planning Considerations

The design, materials and construction of the interior surfaces of an isolation room plays a critical role in the performance of the room in containing infections.
Continuous impervious surfaces such as welded vinyl, epoxy coatings or similar durable surfaces.
Welded vinyl floors coved up the walls, and wall finishes that are durable and easy to clean; for example, welded vinyl isolation rooms with smooth finishes, free of fissures or open joints and crevices that retain or permit passage of dirt particles. The use of carpet is discouraged because it is difficult to clean.
Minimization of horizontal surfaces.
Guard rails to protect the walls from damage by beds and mobile equipment.
Epoxy-coated or stainless steel joinery that is easier to clean than uncoated timber.
Windows designed to avoid dust collection areas.
Washable curtains.
Wall-hung toilet pan and basin with non-hand operated taps.
Window setting: Isolated patients can distinguish day and night by looking through the window panes at the isolation room. This is particularly important to the elderly as it relieves symptoms of disorientation.
Signs and labels: All isolation room ductwork systems should be labeled with appropriate warning signs. Appropriate signage should be prominently placed outside the door of isolation rooms. The bedside and other charts should also be labeled once isolation has been ordered for a patient.
Doors: Sliding doors are not recommended but if space is an issue, sliding doors should only used as a last resort due to difficulties with maintenance and maintaining a seal. The pressure differential should force swing doors into the seal; that is, doors should open out of a NPR or open into a PPR).
Communication system- A nurse call system with the capacity for direct communication between the nurse and patient should be available in each room.

Ventilation

HVAC air flow arrangement for class N rooms. An anteroom designed to provide an ‘air-lock’ (no mix of air) between the infectious patient and the common space is placed adjacent to the patient room. The air would flow from the anteroom to the isolation room. Recirculation of exhausted air is discouraged. The exhaust air should be directed to outside, away from air-intakes and populated areas. However, where recirculation may be deemed acceptable, HEPA filters (99.97% @ 0.3 μm DOP) capable of removing airborne contaminants on the supply side must be incorporated. The supply air should be located such that clean air is first passed over the staff/other occupants and then to the patient.

In Class P rooms can be either 100% fresh air or can use re-circulated air usually a 60/40 mix of outdoor air/ re-circulated air. The supply air should be located such that clean air is first flows across the patient bed and exits from the opposite side of the room. Air distribution should reduce the patient’s exposure to potential airborne droplet nuclei from occupants. Positive pressure rooms may share common supply air systems

Emergency Rooms and Reception Areas

The likelihood of airborne contaminants leaving these rooms is reduced by keeping these rooms under negative pressure, relative to surrounding areas. Air is exhausted from these rooms either directly to the outside or through high efficiency particulate air (HEPA) filters.

Anterooms

If space and budget permit, an anteroom should be pro- vided between the negative/positive pressure isolation room and the corridor It is always recommended for both positive and negative isolation rooms for three main reasons:

To provide a barrier against loss of pressurization, and against entry/exit of contaminated air into/out of the isolation room when the door to the airlock is opened.
To provide a controlled environment in which protective garments can be donned without contamination before entry into the isolation room.
To provide a controlled environment in which equipment and supplies can be transferred from the isolation room without contaminating the surrounding areas.

Fire Plan

As per fire safety manual, the isolation suite is intended to be built as a single fire compartment. The positive pressure in the lobby will detect smoke originating in the corridor from entering the room. Smoke from a fire in the room will be contained within the suite and extracted via the en-suite extract. Because of this the ventilation system serving the isolation facility should be kept running in the event of a fire.
Ductwork thickness should be such that ducts can be considered an extension of the isolation suite. Fire dampers, where the ducts penetrate walls and floors will not then be required.
A motorized smoke/fire damper should be fitted at the discharge of the supply air handling unit (AHU). The damper should close in the event of an AHU or intake fire under the control of a smoke detector mounted in the AHU.

Planning And Designing An Isolation Facility In Hospitals