1. The role of environmental surfaces in disease transmission
Jon Otter, PhD
Scientific Director, Healthcare, Bioquell
Research Fellow, Centre for Clinical Infection and Diagnostics Research (CIDR), King’s College London / Guy’s and St. Thomas’ Hospital NHS Foundation Trust
Visiting Professor, Tokyo Healthcare University

2. Disclosures
I am employed part-time by Bioquell, who produce one of the hydrogen peroxide vapor systems that Bill just talked about!

3. ‘It may some day be…possible to tell who is at fault when one of the communicable diseases is transmitted. If it is ever brought about, it will doubtless be due to the efforts of the bacteriologists.’
Mary M. Riddle. The disinfection of sick-rooms and their contents. Am J Nursing 1901;1:

4. Transfer of a surrogate marker in a NICU
Oelberg et al. Pediatrics 2000;105:

5. Transfer over time: inoculated pod

6. Transfer over time: non-clinical areas

7. Transmission routes
Otter et al. Infect Control Hosp Epidemiol 2011;32:

8. Room A
Room B

9. Room 12
Room 13

10. Room A
Room B

11. 2x
Room A
Room B

12. ‘The room lotto’
Patient infected or colonised with a pathogen (e.g. C. difficile, MRSA, VRE, A. baumannii or P. aeruginosa)
Patient is discharged and the room is cleaned / disinfected; surfaces in the room remain contaminated with the pathogen
The next room occupant is at an increased risk of acquiring the pathogen

13. Percentage of patients with CDI
The C. difficile ‘room lotto’
Setting & design: 18-month retrospective cohort study on an ICU, Ann Arbor, Michigan, USA.
Methods: 134 cases of C. difficile infection occurred among 48 hours after ICU admission or with 30 days of discharge in 1,844 patients admitted to the ICU during the study.
Hazard ratio 2.35, p=0.01
Percentage of patients with CDI
Shaughnessy et al. Infect Control Hosp Epidemiol 2011;32:

14. Increased risk from the prior room occupant
Otter et al. Infect Control Hospital Epidemiol 2011;32:

15. 86% 58% 93% 85% 59% 96% French et al. J Hosp Infect 2004;57:31-37.
Survive for extended periods
59%
96%
French et al. J Hosp Infect 2004;57:31-37.

16. Persistent surface contamination
140 samples from 9 rooms after 2xbleach
5705 samples from 312 rooms after 4xbleach
Results: pathogens build up over time: multiple pulsotypes from the same room; pathogens cultured from empty rooms.
26.6% of rooms remained contaminated with either MRSA or A. baumannii following 4 rounds of bleach disinfection
Manian et al. Infect Control Hosp Epidemiol 2011;32:

17. Environment to hand to patient
Pathogens can be transferred from hospital surfaces to HCW hands without direct patient contact1-2
52% of 23 HCW acquired VRE on their hands3
Contact with patient or surface = ~10% risk of acquiring VRE
45% of 50 HCW acquired MRSA on their hands4
40% of 50 HCW acquired MRSA on their hands4
Compliance with hand hygiene: 50%5
Compliance with hand hygiene: 80%5
Boyce et al. Infect Control Hosp Epidemiol 1997;18:
Bhalla et al. Infect Cont Hosp Epidemiol 2004;25:
Hayden et al. Infect Control Hosp Epidemiol 2008;29:
Stiefel et al. Infect Control Hosp Epidemiol 2011; 32:
Randle et al. J Hosp Infect 2010;76:

18. Standard cleaning / disinfection
Taking the “lotto” out of the room
Comparison of the infection rate of patients admitted to rooms either cleaned and disinfected using standard methods or decontaminated using HPV when the previous occupant had a pathogen.
66% reduction in the rate of acquisition
Standard cleaning / disinfection
HPV decontamination
Passaretti et al. submitted.

19. A tricky question:
“What is your estimation of the % of all C. difficile transmission in hospitals that is mediated, directly or indirectly, by contamination of the inanimate environment?”

21. Surface contamination with pathogens
What to do?
Evidence
Surface contamination with pathogens
Self-
disinfecting surfaces?
Best practice cleaning / disinfection
Optimise disinfection
methods
Monitor performance