Charles P. Gerba Departments of Soil, Water and Environmental Science and Epidemiology and Environmental Health University of Arizona Tucson, AZ

Charles P. Gerba Departments of Soil, Water and Environmental Science and Epidemiology and Environmental Health University of Arizona Tucson, AZ

Percentage of Disease by Transmission Route Animal to human Person to person?%?% Drinking water?%?% Aerosol?%?%?% Fomite Food Recreation

What are Fomites? Inanimate objects involved in the spread of disease

Role of Fomites in Transmission of a Disease Pathogen falls on fomites e.g. phone, computer Person picks up pathogen through contaminated fomite Person touches nose or eyes with contaminated fingers and becomes infected with pathogen Sick person sneezes, coughs and pathogens fall on fomite or get aerosolized 4

Life in the 21 st Century Most of our time is spent indoors (80-90%) More people work in offices than ever before We travel more than ever before We spend less time cleaning than the last generation (50% less than 50 years ago) We are less clean (e.g., laundry practices) We spend more time in public places We are more mobile and have more electronic equipment (e.g., cell phones, ipods) We share more common surfaces (fomites) with more people than ever before in history

Cleaning vs. Hygiene Cleaning is the removal of unwanted matter Hygiene is reducing the risks of infection 6

Cleaning vs. Hygiene Meta-analysis of impact of cleaning and disease reduction indicates normal household cleaning may increase illness rates (Paul Hunter) Cleaning alone may increase risks by spreading pathogens Is cleaning hazardous to your health?

Coliform Bacteria and Escherichia coli (E. coli) Coliform bacteria and E. coli are found in feces and their presence on surfaces indicates contamination by feces and the potential presence of disease causing microorganisms Colonies with a green metallic sheen are counted as total coliforms m-endo Agar

Geometric mean per cm 2 or per ml Enteric Bacteria (Coliforms) in 7 6 5 4 3 2 1 0-1 -2 the Home by Location Sponge Kitchen Sink Bath Sink Cutting Board Kitchen Floor Bath Floor Bath Counter Toilet Seat

Bacteria by the Numbers (per square inch) 200,000 Carpeting 49 Toilet Seat 1,686 Kitchen counter top 2,546 Kitchen tile floor - home 18,025 Bathroom floor - home

Dangers of being a Couch Potato Routes of Germ Exposure - Fabrics aerosol Inhaled Hand Transfer Transfer to Clothing Hand Transfer

How fast does a microbe move in the indoor environment?

The Virus Bacteriophage MS-2 -~23 nm in diameter -single stranded RNA -no lipid layer -similar in shape and size to the cold virus (rhinovirus) and norovirus -commonly used as a model for disinfectant testing

Virus spread in a Home Add MS-2 virus to one hand of and adult in a family of 4 to 6 (does not know hand has been inoculated) on a weekend day Test hands and surfaces in the house after 4 hours Results Virus detected on the hands of all family members hands in the household Virus detected on ~98% of the sites tested positive for virus including» Kitchen table, countertops» Bathroom counters» Living room light switches, TV remotes» Bedroom door handle, sheets, light switches Tamimi et al 2014

The Importance of Cleaning Tools in the Spread of Germs

Number of Germs per Square Inch Bacteria in Offices 16

Quat Wipe / Hand Sanitizer Intervention In an Office Building Add a bacterial virus to the entrance door handle of an office building with 80 persons Collect samples after 2, 4 and 7 hours of fomites and hands

First place virus detected is the coffee break room

Impact of intervention on Occurrence of Virus on Employees Hands

Parainfluenza on Office Fomites Fall 2004 The virus could be detected on ~30% of all surfaces Percentage of Fomites Positive for Parainfluenza 70 60 50 40 Conference Rooms Offices Cubicals 30 20 10 0 New York San Fransico Atlanta Chicago Tucson Total

The Effectiveness of a Chemical Disinfectant Depends on a Number of Important Factors Human behavior Cleaning habits/training, selection of cleaning tools Target microorganisms Bacteria, viruses, molds Type of disinfectant Bleach, quat, hydrogen peroxide, silver, natural product (Thymol) Formulation of the disinfectant Some formulations will not kill all the types of microorganisms you are targeting

The Effectiveness of a Chemical Disinfectant Depends on a Number of Important Factors Bioburden Surfaces need to be cleaned of organic matter before application of the disinfectant Method of application Spray and wipe, cloth soaked in disinfectant, disinfectant wipe, type of cleaning cloth (some have a high demand for the disinfectant) Dwell (contact) time Varies greatly with the type of disinfectant Type of fomite Corrosiveness of the disinfectant, cloth materials, surface roughness

Most Common Disinfectants Used in Homes, Public Places and Hospitals/Health Care Facilities Quats (take 10 minutes) Chlorine Bleach Hydrogen Peroxide

Fabric

Study of Bacteria in Reusable Cleaning Cloths in Hospitals Collected 3 cloths each from 10 different hospitals in Arizona Tested cloths by wetting in trypticase soak broth and then squeezing out the liquid and testing for total bacteria, coliform bacteria, spore formers, MRSA and C. difficile

Average Number of Bacteria in Towels used to Clean Patients Rooms (before use) Hospital Total Bacteria Coliforms* 1 12,600 1 2 63 0 3 6,310 2 4 7,943 0 5 31,622 0 6 100,000 20 7 1,000 0 8 5,012 0 9 6,310 0 10 398 25 *E. coli was identified in two towels

Effect of Cleaning Cloth Material on Bacteria in the Cloth Organism Cotton Microfiber P-value Total bacteria 1,995 24,547 0.01 Coliforms 1 6 0.0002 Molds 1 47 0.001

Effect of Disinfectant Application Method Organism Soaked Sprayed P-value Total bacteria 2,239 104,713 0.01 Coliforms 1 18 >0.0001 Mold 1 2,188 >0.0001 Spores 15 4,074 0.04

Dry Steam Vapor Intervention Study by Sexton, Tanner, Maxwell, and Gerba: Reduction in microbial load on high-touch surfaces in hospital rooms using a steam vapor disinfection system. Research Sponsor - Advanced Vapor Technologies 30

Water is Transformed into Super-heated Low-moisture Steam 31

Advantages of a Saturated Steam Vapor Disinfection System No chemicals Works on fabrics Rapid kill of microorganisms - seconds Works against viruses, bacteria (spores), molds 32

Dry Steam Vapor Intervention Results A The steam vapor device reduced total microbial and pathogen loads to below detection in most instances Research Sponsor - Advanced Vapor Technologies 33

Rapid kill of microbes 34

Dry Steam Vapor Intervention Results B Reduced total coliforms by 83% (40/48) to 13% (6/48). Reduced MISA (12/48) and MRSA (3/48) to below detection. Research Sponsor - Advanced Vapor Technologies 35

Dry Steam Vapor Intervention Results C Reduced bacterial levels by >90% and reduced pathogen levels on most surfaces to below the detection limit. Research Sponsor - Advanced Vapor Technologies 36

Dry Steam Vapor Intervention Research Conclusion May reduce microorganisms without the drawbacks associated with chemicals, and decrease cross-contamination. Research Sponsor - Advanced Vapor Technologies 37

Impact on Bioburden and Biofilm Dry Steam Vapor technology rapidly kills highly resistant biofilms with greater than 99.95 percent killing efficiency in a three-second treatment, and to a non-detectable level in a less than 10 second treatment. Sponsored study at the University of Michigan

Summary of Technology No chemicals Rapid Kill of viruses, bacteria, and molds Active against biofilms Works on Fabrics 39