This document discusses engineering controls for infection prevention through hospital facility design. It outlines various factors that contribute to healthcare-associated infections and their impact. It then provides guidance on key design considerations for hand hygiene stations, isolation rooms, HVAC systems and more to help limit the spread of infections in hospitals. The goal is to partner architects, designers and builders with healthcare staff to incorporate infection control best practices into facility planning and renovation.

1. Engineering Infection Control
through
Facility Design
Dr Ruchi Kushwaha
Hospital Administrator

2. Conduct protocol
Introduction
Fact Sheet of HCAI
Factor responsible for HCAI
Impact of HCAI
Infection prevention & control measures
Hand Hygiene
Isolation rooms
Planning parameters for Ward, OT, ICU
Finishes & Floors, Walls, Ceilings, Doors, Windows, Interior designs, Fixtures &
Fittings
Role of HVAC Systems in Infection Control
Conclusion

3. “In today’s healthcare arena, changes are occurring so rapidly and
dramatically that yesterday’s trend will not be tomorrow’s trend,
causing one to stay fluid & flexible as strategies for the future are
developed.”
-(R Clayton McWhorter in ‘Hospital and Healthcare Facility Design)

4. Introduction
The physical design of hospital is an essential component of a hospital’s
infection control strategy, incorporating infection control issues to minimise
the risk of infection transmission
The role of infection control in the design of facilities has become
increasingly visible as communicable diseases like tuberculosis and
multidrug resistant organisms have caught the attention of the media
affecting both consumer awareness and regulatory agencies responsible
for environmental health and sanitation
Many medical centers have modified their facility design to provide a safer
environment for patients
From an infection control perspective, the primary objective of hospital
design is to place the patient at no risk for infection while hospitalized

5. Healthcare associated Infection (HCAI)
“Healthcare associated/nosocomial/ hospital acquired infection affects
patient in a hospital or other healthcare facility, and are not present or
incubating at the time of admission. They also include infections acquired by
patient in the hospital or facility but appearing after discharge, and
occupational infection among staff.”
- WHO Infection Control Consortium

6. Fact Sheet of HCAI
Hundreds of millions of patients are affected by health care-associated
infections worldwide each year, leading to significant mortality and
financial losses for health systems
Of every 100 hospitalized patients at any given time, 7 in developed and
10 in developing countries will acquire at least one HCAI
The endemic burden of HCAI is also significantly higher in low- and
middle-income than in high-income countries, in particular in patients
admitted to ICU and in neonates
At any given time, the prevalence of HCAI in developed countries varies
between 3.5% and 12% whereas it is 5.7% and 19.1% in low- and middle-
income countries respectively

7. Factors, put patients at risk of Infection in
Health-care Settings
Prolonged and inappropriate use of invasive devices and antibiotics
High-risk and sophisticated procedures
Immuno-suppression and other severe underlying patient conditions
Insufficient application of standard and isolation precautions
Inadequate environmental hygienic conditions and waste disposal
Poor infrastructure
Insufficient equipment
Understaffing
Overcrowding
Poor knowledge & application of basic IC measures
Absence of local and national guidelines and policies

8. Impact of Health Care-associated Infections
Prolong hospital stays
Create long-term disability
Increase resistance to antimicrobials
massive additional financial burden for health systems
Generate high costs for patients and their family
Unnecessary deaths

10. “If the burden of Healthcare associated Infection is to be reduced, it is
imperative that architects, designers and builders be partners with
healthcare staff and infection control teams when planning new facilities or
renovating older buildings.”
-Infection control in built environment D & P
NHS

11. Builders
Architects
Designers
Healthcare staff
Infection control teams

12. Hand Hygiene
“A process that reduces the number of microorganisms on hands. It is a
general term applied to the use of soap/solution (non-antimicrobial or
antimicrobial) and water or a waterless antimicrobial agent, to the surface of
the hands (e.g. alcohol-based hand rub). When performed correctly, hand
hygiene results in a reduction of microorganisms on hands.”
- AusHFGs
Hand hygiene may be classified as:
Routine/social, including patient care situations
Aseptic procedures
Surgical procedures

13. Hand Basin Types & Uses
Hand hygiene compliance is significantly improved when hand basins are
visible and accessible
Depending on their use, hand basins may be as:
1) Clinical - large ‘scrub’ (Type A)
2) Clinical - medium (Type B)
3) Non-clinical - small or medium (including vanities) (Type C)
4) Surgical scrub troughs

14. Hand Basin Design
Have no overflow
Have curved sides, to minimise splashing
Large enough to enable good hand hygiene techniques
Either sealed to the wall or far enough away from the wall to allow effective cleaning
Have a waterproof splashback
Have suitable taps
Do not include integrated plugs
Have water delivered at a suitable temperature to allow hand washing under running
water
Hand basins should be made of a hard, non-scratch material (porcelain) and be easy
to clean
Polycarbonate or other moulded plastic materials are not suitable
Drainage design should be easy to access internally and externally for regular
cleaning of ‘S’ bends to remove biofilm build-up

15. TYPES TYPE A - CLINICAL BASIN -
LARGE (SCRUB BASIN)
TYPE B - CLINICAL
BASIN - MEDIUM
TYPE C - NON-CLINICAL
BASIN - SMALL / MEDIUM
DESIGN • Large wall-mounted type
• Hands-free taps that may be wall
mounted elbow taps, foot/knee
• operated or electronic sensor taps
Warm and cold water delivered by
a common spout
• Tap placement should allow
washing up to the elbow
• Medium wall-mounted
type
• The taps may be either
wall-mounted or basin-
mounted with elbow or
wrist hands-free
operation
• Warm/cold free-running
water
• Small wall-mounted basin
• The taps may be wall-
mounted or
• basin-mounted
• Supply warm and cold
water
• For ease of cleaning and
use taps should be lever
operated as commercially
available
AREA in selected areas requiring clinical
hand washing prior to undertaking
selected procedures that may occur
in non-operating room settings (e.g.
delivery room)
in areas requiring hand
hygiene by staff and visitors
for patient care situations
and aseptic procedures
in areas such as public
amenities

16. Hand Washing
Hand washing in hand basins is generally reserved for situations when
hands are visibly soiled
Soap
All basins should be provided with near neutral pH soap
Clinical basins and scrub troughs should, in addition, be provided with
antimicrobial liquid soap
Soap dispensers are to be the closed-cartridge type and are to be
mounted on or above the splashback

17. Hand Drying
Single use cloth or paper towels will be provided at all hand basins
Locate towel dispensers adjacent to the splashback to prevent splash
contamination
Dispensers should be smooth-surfaced and easy to clean to prevent dust
or soil contamination
Paper towel may be used in public amenities and beverage bays
Hot air hand dryers are not recommended for installation in clinical areas
of healthcare facilities
High speed hand dryers may be considered in non-clinical areas, such as
public toilets

18. Alcohol-based Hand Rubs
Alcohol based hand rub (ABHR) improves compliance with hand hygiene and is
the hand hygiene product of choice for all standard aseptic non-touch technique
procedures
ABHR s/b available:
 at the foot of every patient bed or adjacent wall
 affixed to mobile work trolleys (e.g. intravenous, drug and dressing trolleys)
 in high staff traffic areas (staff station, utility rooms and at the entrance to patient
rooms)
 other multi-use patient care areas such as consultation rooms
 at the entrance of each inpatient unit, outpatient clinic and other departments
 in public areas such as waiting rooms, receptions areas, hospital foyers, and near
elevator doors in high traffic areas
Dispenser systems should minimise the possibility of ‘dripping’ to avoid potential
damage to wall and floor coverings

19. Gloves
A disposable glove dispenser, sufficient to hold all glove sizes (usually three
sizes), should be located near areas where staff are likely to come into contact
with blood and body fluids
The dispenser should allow restocking without the need to touch new gloves, and
be located away from the splashback to prevent splash contamination
Glove dispensers will be located in areas such as inpatient bed rooms,
emergency treatment bays and dialysis bays where staff are identified as being at
risk of exposure to blood and body fluids at the point of care
Hand Cream / Lotion
Locate a moisturising cream/lotion dispenser at or near each hand basin
Dispensers should be non-refillable
Hand cream/lotion should be compatible with all hand hygiene products

20. Arrangement of Dispensers at Clinical Basins
Dispensers should be arranged in a
consistent manner across HCF
Glove dispensers should be located to
the staff members’ left and hand towels
to the right
Soap and hand cream/lotions
Dispensers should be mounted over
the basin to ‘catch’ drips

21. Signages
Clear visible signs reminding all staff and visitors to attend to hand hygiene
should be provided
Waste Receptacles
Locate waste receptacles at each hand basin for disposal of single use
towels
The bins should be of adequate size, non-touch design and easy to clean
Mirrors
Mirrors should not be installed above hand basins in food preparation
areas, nurseries, clean and sterile supply areas and other areas where
infection prevention and control would be compromised by staff touching
their hair
Mirrors may be installed in anterooms, near PPE bays and near the entry
to surgical scrub rooms, to assist staff to correctly don caps, masks and to
check their hair is appropriately covered

22. Scrub Sink/Trough
This is a long sink that can accommodate one or more staff scrubbing for a
surgical procedure
Taps and Waterspouts
The use of spray taps and hoses is not supported in clinical environments
as they create aerosols
A domestic style single lever operation is considered an appropriate
substitute for a wrist operated tap

23. Isolation Room
Whenever possible, a patient known or suspected to harbour transmissible
microorganisms should be placed in a single room with hand washing and
toilet facilities
A single room helps prevent direct or indirect contact transmission or
droplet transmission
Types-
1) Class S - Standard Isolation Room
2) Class P - Positive Pressure Isolation Room
3) Class N - Negative Pressure Isolation Room
4) Class Q - Quarantine Isolation Room
5) Combined Alternating Pressure Isolation Rooms

24. Class S - Standard
Isolation Room
Class P - Positive
Pressure Isolation
Room
Class N - Negative
Pressure Isolation
Room
Class Q -
Quarantine Isolation
Room
Combined
Alternating Pressure
Isolation Rooms
single room with an
en-suite that is not
shared
a single room with
an ensuite that is
not shared
a single room with
an ensuite that is
not shared
A Class Q isolation
room is a single
room with a
dedicated ensuite
that is not shared
enabling the room to
have either negative
or positive pressure
used for patients
who require
isolation to minimise
the potential for
infections being
transmitted by
contact or droplets
to other patients and
staff
used to reduce the
risk of airborne
transmission of
infection to
susceptible patients
with prolonged
granulocytopenia,
such as
allogeneic bone
marrow recipients
used for patients
who require
isolation to reduce
airborne
transmission of
disease (e.g.
varicella, measles,
pulmonary or
laryngeal
tuberculosis)
patients with highly
infectious
pathogens such as
haemorrhagic fevers
and pneumonic
plague. These
patients require a
further level of
containment over
and above the
standard negative
pressure isolation
room
NOT recommended
due to-
• Difficulty in the
configuration of
appropriate
airflow for two
fundamentally
different
purposes
• Risk of operator
error

25. Class S - Standard
Isolation Room
Class P - Positive
Pressure Isolation
Room
Class N - Negative
Pressure Isolation
Room
Class Q -
Quarantine Isolation
Room
Combined
Alternating Pressure
Isolation Rooms
• Type B HWB
within the room
• Self-closing
doors to control
room temp.
• A PPE bay may
be provided
outside the door
and may be
shared with an
adjoining room
• No specific
requirements for
air conditioning
• A Type B HWB
within the room
• Self-closing
doors to control
room pressures
• The positive
pressure air
handling system
within the room
operates at a
higher pressure,
wrt adjacent
rooms/spaces
• Waste disposal
should be
provided inside
the room
• A Type B HWB
within the room
• Self-closing door
are required
• Sufficient &
appropriate
storage for
clinical waste
• The design of the
room must
provide separate
entry doors to
allow for
movement of the
patient in and out
of the room
• The anteroom is
only for use by
staff and visitors
• All design
requirements as
described for a
negative
pressure room
• In addition, the
quarantine
isolation room
will require an
anteroom
designed to
function as an
absolute airlock
• Need for complex
engineering

26. Class S -
Standard
Isolation
Room
Class P - Positive
Pressure Isolation
Room
Class N - Negative
Pressure Isolation Room
Class Q - Quarantine
Isolation Room
Combined
Alternating
Pressure
Isolation Rooms
• Air supply is high
efficiency particulate
air (HEPA) filtered
Air exhausted from
these rooms is not
infectious and
therefore does not
require filtration
• An enclosed
anteroom is not
required, but
sufficient and
appropriate storage
space s/b provided
outside the room for
PPE
• The air handling system
operates at a lower
pressure wrt adjacent
areas such as the
anteroom and corridor
• Air in negative pressure
rooms will be exhausted
to the outside to prevent
air recirculation Ideally,
supply air into the room
should be located on the
ceiling above the foot of
the bed The exhaust air
to be located at the head
of the bed
• Inclusion of an
electronic
communication
system (intercom)
between the
isolation room and
the airlock will
assist in
eliminating or
reducing
unnecessary
traffic into the
room

27. Isolation Room Checklist
Sl.
No.
Parameters Class-S Class-N Class-P
1. Hand wash basin in room Yes Yes Yes
2. En-suite Bathroom
(Shower, toilet, WHB)
Yes Yes Yes
3. Door with door closer Yes Yes Yes
4. Airlock - Yes Optional
5. Sealed room, door - Yes Yes
6. Pan sanitiser (near room) Optional Optional Optional
7. Independent exhaust Yes
8. HEPA filters on supply - - Yes
9. Air changes/hour - 6-12 6-12

28. Calculation of Numbers of Single Rooms
Assessment of actual demand for patient isolation should include:
Number of patient admissions with infections known or suspected to require
isolation
Type and duration of isolation required
Clustering of cases that may be influenced by seasonal and other trends
Type of units where patient isolation may be necessary
Estimates of numbers and types of isolation rooms should consider:
Trends in disease in the general population and the particular population served
Demographic trends in the population served
Specialties of the healthcare facility
Projected changes in future clinical activities

29. Design Principles for Isolation Rooms
The aim of environmental control in an isolation room is to control the
airflow, thereby reducing the number of airborne infectious particles that
may infect others within the environment
This is achieved by:
Controlling the quality and quantity of intake and exhaust air
Diluting infectious particles in large volumes of air
Maintaining differential air pressures between adjacent areas
Designing patterns of airflow for particular clinical purposes

30. When planning isolation rooms consider:
Sufficient and appropriate storage space for waste receptacles inside the
room
Sufficient and appropriate storage space for PPE outside the room
Provision of an observation window with a privacy blind between double
glazing (to allow staff to observe patients without entering the isolation
room)
Provision of a communication system such as a phone or intercom to
allow communication between staff, patients, interpreters, visitors etc.
without leaving the room
Suitable surface finishes (ceiling, walls, floor coverings etc.)

31. Airlocks for Class-Q Rooms
Anterooms in Class Q rooms act as full airlocks with two interlocking doors
that cannot be opened simultaneously
The airlock will need to be large enough to incorporate additional disposal
facilities as well as allowing bed movement with doors interlocked
Ensuring that the pressure in the airlock is lower than the adjacent ambient
(corridor) pressure, and positive with respect to the isolation room
The pressure differential between rooms should be no less than 15
Pascals
The door to the airlock from the corridor is to be well sealed with good
quality seals on each side
The airlock should have supply air (no exhaust) with a door grille between
the airlock and the isolation room

32. The physical design of hospital is an essential component of a hospital’s
infection control strategy, incorporating infection control issues to minimise
the risk of infection transmission
The role of infection control in the design of facilities has become
increasingly visible as communicable diseases like tuberculosis and
multidrug resistant organisms have caught the attention of the media
affecting both consumer awareness and regulatory agencies responsible
for environmental health and sanitation
It is of paramount importance to consider hospital infection control
measures while planning various departments like wards, operation
theatre (OT), intensive care unit (ICU), central sterile supply department
(CSSD), dietary, laundry etc.

33. Planning Parameters
The aim of a hospital planner is to achieve a good hospital architectural
design for better infection control
At the planning stage itself certain criteria and principles were kept in mind
to be fulfilled:
The design should support functional segregation of OPD, inpatients,
diagnostic services and supportive services so that mixing of patient flow is
avoided
Separation of critical areas like OT, ICU from general traffic and avoidance
of air movement from areas like laboratories and infectious diseases
wards towards critical areas
The design should support concept of zoning and ventilation standards in
acute care areas

34. Planning Parameters
The clean corridor and dirty corridor should not be adjacent and they
should facilitate traffic flow of clean and dirty items separately
Isolation wards for infectious cases to be kept out of routine circulation
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
Construction of isolation rooms within the wards including ICU and acute
care areas
Provision of airlock and anteroom before entering into critical care areas

35. Design of Ward Units
Control of infection in wards not only requires application of the principles
of asepsis and hygiene but also considerations of design, equipment and
ventilation of wards
Hand washing has been recommended as the single most important
practice to control hospital acquired infection
The number of sinks and their placement should be thoughtfully planned to
encourage health care worker to practise hand washing before and after
every patient care activity
Nursing of each patient separately is ideal, at least 2-4 single rooms for a
30 bed unit are sufficient
Moreover, overcrowding in pavilion wards should be avoided by keeping
centres of beds at least 8 feet apart

36. Design of Ward Units
A general ward was planned based on bed strength ranging from 24-32
beds on rigs pattern where 2 single bed rooms, 2 four bedded rooms and
rest 6 bedded rooms were planned
One wash hand basin (WHB) each for these rooms averaging one WHB
per six beds was Provisioned
Floor space area per bed was kept to 7 sqm excluding central corridor of
2.4 meters
Single bed rooms were given 14 sqm and distance between centres of
beds in 6 bedded rooms was coming to more than 2.5 meters

37. Design of Ward Units
As per standard guidelines a space should be provided to keep urine,
stool samples of patients, their disposal, washing and storage of
contaminated / soiled linen, place to make disinfectant solution and
placement of bedpans etc
Dirty utility and soiled linen room of size 10.5 sqm per ward with facilities
for bed pan sink, Macintosh sink and slop sink is planned
Water supply of hot and cold water was catered and in addition janitors
closet of 3.5 sqm for keeping mops and detergents was provisioned in
each ward
One to two standard isolation rooms per ward unit were planned
throughout the hospital

38. Planning of ICU
At least one cubicle per eight beds
Sufficient space around each bed- at least 20 sqm,
WHB between every other bed
Ventilation including positive and negative pressure ventilation for high risk
patients
Sufficient storage and utility space
Floors and walls should be easily cleanable and non porous
Dirty utility should have separate stand / shelf per bed, bedpans, urinals, to
be kept dry and hand wash solutions basins at each bedside

39. ICU of eight beds with 2 additional isolation cubicles is planned
Each bed will have 14 sqm floor space
Adequate place for bed head unit and separate sterile supplies
Each isolation cubicle is planned with self closing door and airlock
Air lock is supposed to have following functions-
Provide a barrier against loss of pressurisation and against entry / exit of
contaminated air into / out of the isolation room
They provide a controlled environment in which protective garments can
be donned
They also provide a physical and psychological barrier to control
behaviour of staff in adopting infection control practices

40. 15 air changes per hour (5 fresh + 10 re-circulation) as per minimum ASHRAE
Standards
Positive pressure gradient of 15 Pa is recommended between isolation cubicle
and main ICU
One WHB between two beds alongwith stands for holding hand wash solutions
for each bed is planned to promote hand washing practice
A dirty utility with place to prepare fresh KLICK’s solution (Sodium hypochlorite)
and stand for bedpans, urinals along with bedpan sink, Macintosh sink and slop
sink have been designed
Automatic air curtain has been planned at the air lock and entry into patient care
area in ICU, acute care wards, OT sterile area, neonatal ICU, delivery suites
They have the capability of keeping outside environment separate from inside
environment in critical care areas

41. Planning of Operation Theatre
Basic requirements for control of infections in O.T.
Separation from general traffic and air movement of hospital
Zoning i.e. sequence of increasingly clean zones from the entrance to the
operating area with the aim of reaching absolute asepsis at operating site
Easy movement of staff from one clean area to another without passing
through dirty areas
Removal of dirty materials from the suite without passing through clean
areas

42. Objectives of ventilation system in OT:
To dilute the bacteria generated by the operating team and patients in the
theatre by appropriate air volume changes
To prevent less clean air from neighbouring rooms entering the OT by
using different air pressures
To create an air flow pattern that carries contaminated air away from the
operating table
To provide a comfortable environment for the operating team and patients
with controlled temperature, humidity and ventilation

43. Sterile Zone:
I. Temperature: 23°C ± 3°C
II. Relative humidity : 40% to 60%
III. Fresh air allowance : 10 per hour with total air changes 25 per hour
IV. Air filters : through HEPA filters with filtration level upto 0.3 microns and
99.97% efficiency with pre filters in the system
V. Positive pressure = 25 Pa
Other areas :
I. Fresh air changes minimum 5 per hour and total 15 per hour
II. HDPE washable filters with filtration level upto 5 microns

44. One separate dedicated AHU designed to maintain positive pressure
gradient so as to ensure flow of air from sterile to clean and protective
zone
Aluminium air conditioning ducts with differential pressure gauge /
manometer across HEPA filters so as to detect clogging or reduced flow of
air
No shelves will be provided inside OT
Purified water will be supplied for scrub with steel scrub and facility of
dispensing of hand wash solution as well as water through foot control
Air curtains at the entry of sterile zone have been planned

45. Recommended floor surface is epoxy resin flooring, however, authorities
in the channel were of the opinion that marble slabs of suitable size with
copper strips should be provided
Epoxy flooring has been found to be seamless, scratch proof, hard
enough for wheeled trolleys, stain free and antistatic
Laminar flow which is a low turbulence downward displacement air flow
towards the operation zone through stainless steel perforated grills has
been planned
Drains, sewerage pipes and water line have been avoided at least near
and above OT sterile zones

46. Finishes & Floors, Walls, Ceilings, Doors,
Windows, Interior designs, Fixtures & Fittings
The quality of finishes in all areas s/b of a high standard, and cost effective
Soft furnishing must be covered in an impervious material within all clinical
and associated areas
Flooring- smooth, easily cleaned and appropriately wear resistant
The use of carpet is not advised within any clinical or associated area.
Attractive vinyl flooring material are available which can provide aesthetic
appeal
Acoustical tiles should be avoided in highrisk areas because they may
support microbial growth when Wet

47. Walls- smooth, hard, impervious surface s/b used
All joints & crevices s/b sealed
Curtains must be able to withstand washing processes at disinfection
temp.
Windows blinds s/b used with caution
All surfaces s/b designed for easy cleaning
All surfaces, fittings, fixtures and furnishings s/b designed for easy
cleaning and durability

48. Pipe penetrations and joints should be tightly sealed
False ceilings may harbour dust and pests that may contaminate the
environment if disturbed, so should be avoided in high-risk areas unless
adequately sealed

49. Role of HVAC Systems in Infection Control
Some of the ways that potentially infectious microorganisms can be
spread in a health care environment include
sneezes and coughs
inhalation
contact
deposition in surgical site or open wound
water mist
insect bite

50. HVAC systems can impact HAIs by affecting
dilution (by ventilation)
air quality (by filtration)
exposure time (by air change and pressure differential)
temperature
humidity
organism viability (by ultraviolet [UV] treatment)
airflow patterns

51. Conclusion
The design of health-care facilities has undergone substantial changes in
large part because patients with impaired host defences now represent an
increasing proportion of hospitalizations
As a result, both design and renovation of these facilities present unique
challenges and opportunities for infection control professionals, who are
often the only clinical staff associated with construction Projects
Early involvement in the process can make appropriate communication
easier and protect patient safety
Ultimately, while time-consuming, participation in hospital design,
construction, and renovation can serve as another marker of how infection
control professionals improve the quality of patient care

53. Refences
CDC Emerging Infectious Diseases, Vol. 7, No. 2, March–April 2001
Infection control in built environment, planning & Designing, NHS Estates
Australasian Health Facility Guidelines, Part D - Infection Prevention and
ControlD.0002 - Building Elements
ASHRAE_HVAC-HospitalBook_WHOLE-BOOK_PRF_2-12-13-wg
Designing Hospital for better Infection Control :an Experience MJAFI, Vol.
60, No. 1, 2004
Health care-associated infections Fact Sheet

54. Thank You !
Your feedback and comments will be appreciated !
drruchi21@gmail.com