This document discusses the use of ultraviolet (UV) technology to disinfect surfaces and reduce the transmission of healthcare-associated infections (HAIs). It provides background on the risks of HAIs and the role of contaminated environmental surfaces in transmission. The document then describes how no-touch UV disinfection systems work to deactivate pathogens using UV-C light. Several studies are summarized that demonstrate the effectiveness of UV in reducing bacteria and spore counts on surfaces. The advantages and disadvantages of UV disinfection technology are also reviewed. Examples of several UV disinfection devices currently used in hospitals are provided.

1. UV Technology for
UV Technology for
Disinfecting Surfaces
Disinfecting Surfaces
By
Dr Anjum Hashmi
MBBS,CCS(USA),MPH
Infection Control
Director,
Maternity & Children’s
Hospital
Najran KSA

2. Introduction
Introduction
• Healthcare-associated infections remain an
important source of morbidity and mortality,
with an estimated 1.7 million infections and 0.1
million deaths annually.
• The major source of nosocomial pathogens is
thought to be patients’ endogenous flora, but an
estimated 20%–40% of healthcare-associated
infections have been attributed to cross infection
via the hands of healthcare personnel.
• Contamination of the hands of healthcare
personnel could in turn result directly from
patient contact or indirectly from touching
contaminated environmental surfaces.

3. Introduction
Introduction
• The risks associated with hospital & community
acquired infections are enormous for both
human health and medical costs.
• Scientific literature confirms that Clostridium
difficile, MRSA, VRE, Acinetobacter baumannii,
and influenza are transmitted via
environmental surfaces.

4. Introduction
Introduction
• Published studies indicate that only 50% of
environmental surfaces in a typical OR suite or
patient room may be effectively disinfected by
routine environmental cleaning.
• Thus patient’s risk of contracting an HAI
increases 100% when the previous room
occupant had been diagnosed with an
infection.

5. “
“Targeting Zero” initiative
Targeting Zero” initiative
• Recently, APIC began a “Targeting Zero” initiative
focused on eliminating HAIs.
• Improvements have been made in infection control
in recent years but, the environment remains a
significant problem.
• We are still cleaning the environment in the same
manner as we were doing decades ago, except
change to new chemicals.
• We will not achieve zero HAIs until new
technologies are used in the environmental cleaning
sector as well.

6. No-Touch Disinfection System
No-Touch Disinfection System
• No-touch disinfection, also called “area
disinfection," is a means of disinfecting an
enclosed space.
• This can be achieved using either ultraviolet
light (UV) or hydrogen peroxide vapor (HPV).
• In both cases, a device is placed into a patient
room, operating room or other area while the
room is unoccupied and the device is run for
specified time (disinfection cycle).

8. Mechanism of Action
Mechanism of Action
• UV-C technology rapidly and cost effectively deactivate
viruses, mold and bacteria that could otherwise
threaten people's health.
• UV-C energy passes through the cell walls of bacteria,
viruses and bacterial spores & it is absorbed by the
DNA, RNA and proteins.
• The primary mechanisms of damage created by UV-C is
the fusing of the strands of DNA creating what is known
as "thymine dimers."
• Once the DNA is fused, the organism can no longer
replicate and is, therefore, no longer infectious. The
technical term for this is "deactivation."

9. Type of Ultraviolet Light
Type of Ultraviolet Light
• The application of UV-C energy to deactivate
microorganisms is known as Germicidal Irradiation or
UVGI.
• Optimal wavelengths vary for UV-C disinfection of
different organisms. On average, wavelengths of 250-265
nm are where peak DNA absorption occurs.
• Mercury Ultraviolet It is most familiar form of UV is that
is produced by mercury vapor lamps. In these lamps, the
mercury vapor is ionized to create UV-C of 254 nm.
• Pulsed Xenon Ultraviolet (PX-UV) It is produced by
pulsing a xenon lamp which produces a broad spectrum
UV (from 200 nm to 320 nm) covering entire germicidal
UV band.

12. Literature Review
Literature Review
• UV-C light unit significantly reduced aerobic
colony counts and C. difficile spores on
contaminated surfaces in patient rooms.
• UV -C technology eliminate more than 3-log10
vegetative bacteria (MRSA, VRE, and
Acinetobacter baumannii) and more than 2.4-
log10 C. difficile seeded onto Formica surfaces in
experimentally contaminated patient rooms.
• William A. Rutala, David J. Weber, Are Room Decontamination Units Needed to Prevent
Transmission of Environmental Pathogens? Infection Control and Hospital Epidemiology August
2011, vol. 32, no. 8

13. Literature Review
Literature Review
• There is ample evidence that no-touch systems
such as UV-C light can reduce environmental
contamination with healthcare-associated
pathogens.
• UV-C light unit significantly reduced aerobic
colony counts and C. difficile spores on
contaminated surfaces in patient rooms.
• John M. Boyce, Nancy L. Havill, Brent A. Moore, Terminal Decontamination of Patient
Rooms Using an Automated Mobile UV Light Unit. Infect Control Hosp Epidemiol
2011;32(8):737-742

14. Mean number of colony-forming units (CFU) of C. difficile, MRSA, and VRE
from contaminated surfaces in hospital rooms before & after disinfection with
UV .
Two-hundred sixty-one total surfaces from 66 rooms were cultured, including
call lights, bedside tables, telephones, and bed rails.
Nerandzic et al. Evaluation of an automated ultraviolet radiation device for decontamination of Clostridium
difficile and other healthcare-associated pathogens in hospital rooms. BMC Infectious Diseases 2010, 10:197

15. Mean aerobic colony counts before and after UV light
Mean aerobic colony counts before and after UV light
treatment for 5 high-touch surfaces in 20 rooms
treatment for 5 high-touch surfaces in 20 rooms

16. Literature Review
Literature Review
• Germicidal Irradiation or UVGI is very
effective in decontamination of
Acinetobacter baumannii form all metal
surfaces i.e., complete killing of
Acinetobacter baumannii from
contaminated surfaces was achieved
with Ultraviolet C Light.
• Vipin K. Rastogi, Vipin K. Rastogi, Lalena Wallace, Lisa S. Smith. Disinfection of Acinetobacter
baumannii-Contaminated Surfaces Relevant to Medical Treatment Facilities with Ultraviolet
C Light. MILITARY MEDICINE, 172, 11:1166, 2007

17. Literature Review
Literature Review
• Pulse xenon ultraviolet light is an effective
and efficient means of disinfecting surfaces
contaminated with Clostridium difficile spores,
MRSA and/or VRE, providing an alternative
means to bleach and other chemical
disinfectants for use in clinical settings.
• Mark Stibich. Use of Pulse Xenon Ultraviolet to Deactivate Clostridium Difficile spores,
Methicillin-Resistant Staphylococcus Aureus and Vancomycin-Resistant Enterococci .
SHEA/Fifth Decennial 2010.

18. UV irradiation Advantages
UV irradiation Advantages
• Reliable biocidal activity against a wide range of healthcare-
associated pathogens
• Room surfaces and equipment decontaminated
• Room decontamination is rapid (!15 minutes) for vegetative
bacteria Effective against Clostridium difficile, although longer
exposure is required (!50 minutes)
• HVAC system does not need to be disabled, and the room does
not need to be sealed
• UV light is residual-free and does not give rise to health or
safety concerns
• No consumable products so costs include only capital
equipment and staff time
• Good distribution in the room of UV energy via an automated
monitoring system

19. UV irradiation Disadvantages
UV irradiation Disadvantages
• All patients and staff must be removed from the room
before decontamination
• Decontamination can be accomplished only at terminal
disinfection (i.e., cannot be used for daily disinfection)
because the room must be emptied of people.
• Capital equipment costs are substantial.
• Does not remove dust and stains, which are important
to patients and visitors; hence, cleaning must precede
UV decontamination.
• Sensitive to use parameters (e.g., wavelength, UV dose
delivered).
• Requires that equipment and furniture be moved away
from walls.

21. UV Technology
UV Technology
Gadgets
Gadgets

22. V-PAD
V-PAD

23. V-PAD (Portable Area
V-PAD (Portable Area
Disinfection)
Disinfection)
• Four maximum output extended length
UV-C lamps with combined output of
600 watts.
• Digital timer/counter to set disinfection
cycle times of up to 99 hours.
• Four infrared motion sensors to
automatically shut off device if
someone enters the room during the
disinfection cycle.
• Metal reflectors to protect lamp and
better distribute UV energy
• Tri-color LED indicates status of
operation.

25. TRU-D Smart UVC™ with
TRU-D Smart UVC™ with
Sensor360™ technology
Sensor360™ technology
• TRU-D Smart UVC™ is the portable UV disinfection
system that precisely measures reflected UVC
emissions with Sensor360™ to automatically deliver the
pathogen-lethal UV dose required for each room,
dynamically compensating for room size, shape and
other dose altering variables such as the position of
contents, windows, blinds and doors.
• TRU-D uses narrow band UVC light for a high efficiency
targeting of the DNA-disrupting wavelength that stops
pathogens.
• TRU-D is safe to use in rooms with glass windows and
doors. UVC is not transmitted through glass windows.

27. XENEX(
XENEX(Hospital Disinfection))
Hospital Disinfection))
• Pulsed-xenon UV lamp delivers the fastest,
most effective germicidal dose of any UV
system
• Lamp™ system uses reflectors and
movement to focus UV light toward “high-
touch” surfaces
• On-board database logs system activity for
utilization tracking and analysis
• Visible light filter blocks the bright xenon
pulse, so that rooms with interior glass can
be treated without Distraction
• Motion detection system and door guard
ensure the safety of patients, visitors, and
staff.

28. Reputed Hospitals Using UVGI
Reputed Hospitals Using UVGI
Presbyterian Hospital USA
Presbyterian Hospital USA
Henry Mayo Hospital USA
Henry Mayo Hospital USA

29. Vancouver General Hospital Canada
Vancouver General Hospital Canada

30. Cooley Dickinson Hospital,
Northhampton, MA

31. Flux Ropes on the Sun
Image of magnetic loops on the sun, by
NASA's Solar Dynamics Observatory (SDO).
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