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 jon.otter@bioquell.com

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

‘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;1:568-573.

Transfer of a surrogate marker in a NICU Oelberg et al. Pediatrics 2000;105:311-315.

Transfer over time: inoculated pod

Transfer over time: non-clinical areas

Transmission routes Otter et al. Infect Control Hosp Epidemiol 2011;32:687-699.

Room A Room B

Room 12 Room 13

Room A Room B

2x Room A Room B

‘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

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;32:201-206.

Increased risk from the prior room occupant Otter et al. Infect Control Hospital Epidemiol 2011;32:687-699.

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.

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;32:667-672.

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;18:622-627. Bhalla et al. Infect Cont Hosp Epidemiol 2004;25:164-167. Hayden et al. Infect Control Hosp Epidemiol 2008;29:149-154. Stiefel et al. Infect Control Hosp Epidemiol 2011; 32: 185-187. Randle et al. J Hosp Infect 2010;76:252-255.

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.

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?”

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