Keeping Out of Touch: The Role of High Touch Surfaces in Home and Community Settings and the Implications for Cleaning and Disinfection Elizabeth Scott Simmons College, Boston Simmons Center for Hygiene and Health in Home and Community. International Forum on Home Hygiene (IFH) www.ifh-homehygiene.org
Historical Perspective • The Morning Gossip. George Cruikshank (1792-1878) • www.viewima ges.com
The Age of the Sanitary Reformers • 1842 Report on the Sanitary • Essentials for healthy home: Conditions of the Laboring Pure air, pure water, efficient Populations of Great Britain drainage, cleanliness, light (Edwin Chadwick) • ‘Miasma’ theory of disease • Florence Nightingale. 1859 Notes on Nursing
New York Council of Hygiene and Public Health 1864 • 1865 report on the sanitary condition of NYC • Metropolitan Board of Health • 1890’s: reductions in urban outbreaks of typhoid & cholera due to improvements in sanitation, water supply & street cleanliness
Late 20 th Century • Latter half of the 20 th century – focus on health care settings. • “Infectious disease is beaten!” • Environment played little role in endemic transmission of healthcare-associated infections • Societal changes: working women, urbanization, travel, removal of household topics from school curricula , globalization of food supply, grouping of susceptibles.
Today…….. • Infectious disease burden • Role of contaminated surfaces in hospitals for endemic/epidemic transmission of C difficile, VRE, MRSA, A baumanii, Ps aeruginosa and norovirus • Improved environmental decontamination contributes to control (Otter et al 2011 Infect Control Hosp Epidemiol)
Why home and community settings? • Growing immuno-compromised population in the community. • Emerging pathogens • Antibiotic resistance • Home-care nursing • Grouping of susceptible individuals • Declining support for surface cleaning/ hygiene practices
Microbial ecology vs microbial risk • Inanimate surfaces are contaminated! • What is the microbial ecology of the indoor environment? • Snapshots vs temporal data • Sampling techniques: ATP vs lab culture vs molecular • Clinical vs non-clinical settings • “Germs”: “good germs” - “bad germs” • Many representatives of human flora, opportunistic pathogens and some pathogens.
Bacterial contamination on planes (McManus & Kelley 2005 J.Appl Micro) • Frequently touched surfaces • DNA sequencing and BLAST analysis to identify sequences in Genbank. • Bacterial diversity highest on lavatory surfaces including door handles, toilet handles and sink faucets . • Detected 58 different bacterial genera • Most frequently observed species came from 5 genera commonly associated with humans: Streptococcus, Staphylococcus,Corynebacterium, Proprionibacterium and Kocuria. • “ Conclusions: The results show that there is a large diversity of bacterial contamination planes, including organisms known to be opportunistic pathogens”
Surfaces in home and community settings • Complex & varied situations • What is the risk? • Setting: e.g. office vs daycare vs home • Occupants & activities • Type and rate & source of contamination • Type of surface • What is the likelihood of contact with a surface? >>high touch surfaces
Criteria for infection risk associated with surfaces. Reference: Block, 5 th ed. 2001
Community – based infections linked to high touch surfaces
Infectious Gastrointestinal Disease • Common but underreported • Up to 50% of transmission person-to-person • Surface involvement • Norovirus, Rotavirus, Campylobacter • Foodborne: 48 million cases of foodborne illness/year USA • >40% of reported foodborne outbreaks occur at home
Skin Infections • Common but under- reported • Direct and indirect transfer involving surfaces • CA-MRSA • San Francisco study: 85% of infections occurred outside of healthcare ( Liu et al. 2008)
Acute respiratory infections • Adults: 1.5-3 infections/year • Children under 5: 3.5-5 infections/year • Loss of productivity & economic burden • Cold viruses, 80% rhinovirus. • Influenza epidemics USA: 36,000 deaths, 114,000 hospitalizations. • Role of hands and surfaces in transmission of influenza.
The transmission equation for hands and high touch surfaces pets raw foods humans temporary reservoir
Pathogen transfer rates from hand contact surfaces to hands • Highly variable • Species and strain specific • Highest from non-porous surfaces
Wet Reservoir Sites • E.coli & fecal coliforms • Salmonella • Shigella sonnei • Norovirus • Risk is relatively low except during outbreaks of enteric infection
Reservoir -disseminator sites • E.coli & other coliforms • Salmonella • Listeria • MRSA • Fungal contaminants • Risk of cross- contamination to other surfaces is constant
Hand & Food Contact Surfaces • E.coli & coliforms (fecals) • Cytomegaolvirus & rotavirus in daycare • MRSA: home, athletic & LTCF • Vancomycin-resistant enterococci (VRE) in LTCF • Rhinovirus & influenza virus in offices. • Risk is variable but constant
Floors, carpets, athletic mats & soft furnishings • C. difficile spores, VRE, Group A streptococci & MRSA in LTCF’s • MRSA in homes and athletic facilities • Enterics (salmonella, rotavirus etc) in daycare • Norovirus – hotels and cruise ships etc. • Risk: for groupings of vulnerables & some specific activities
Examples of pathogen transfer between surfaces and hands. • Campylobacter & Salmonella in kitchens: hands, cutting boards, rags (Cogan et al 1999 Ltts Appl Micro ) • Polio virus following vaccination of infants found on 13% of hand contact surfaces ( Curtis et al 2003 IntJ Enviro Hlth ) • Rhinovirus on 35% hand contact surfaces sampled in hotel rooms ( Winther et al 2007 J Med Virology) • CA-MRSA average transmission to pigskin from hand contact fomites was 62% of bacteria recovered directly from the fomite (Desai et al 2011 AJIC)
Pathogen survival on inanimate surfaces • Most Gram +ve bacteria: months on dry surfaces • CA-MRSA: weeks to months on vinyl and plastic fomites ( Desai et al 2011. AJIC ) • Many Gram –ve bacteria: months • Most respiratory viruses: few days • GI tract viruses, e.g. rotavirus: up to 2 months • (Kramer et al. 2006 BMC Infectious Disease)
SURFACE S.aureus % MRSA % SURFACE S.aureus% MRSA % Sponge/cloth n= 33 30 3 Toilet seat 14 0 Dish towel n=31 27 7 Counter top n=33 12 0 Sink 23 3 Door handle n=34 12 3 Drain 20 3 Faucet handle 11 3 Floor n=34 18 0 Toilet floor 11 0 Phone n=34 15 0 Light switch n=34 9 0 Table top 14 0 Flush Handle n=34 3 0 Counter top n=34 12 3 Child training potty n=10 0 0 ‘Fridge handle 11 0 Other Faucet handle 12 6 Child toy 34 0 Microwave touch n=34 7 0 Infant high chair tray n=26 29 5 Garbage bin n=34 6 3 Infant changing mat n=24 27 0 Chopping board n=32 0 0 Pet food dish 15 3 Bathroom TV remote n=34 12 0 Tub 26 3 Phone n=22 13 0 17 3 Computer Mouse n=31 10 0 Sink Computer Keyboard n=32 3 0 Toilet bowl n=34 15 0
Household Surfaces with MRSA (Scott et al 2009, AJIC) Hand contact vs Non Wet (W) or Dry Surfaces handcontact (D) surface Dish towel Hand D Kitchen countertop Hand D Kitchen faucet handle Hand D Sponge Hand W Bathroom faucet handle Hand D Bathroom door handle Hand D Infant highchair Hand D Pet food dish Hand D Bathroom sink Hand W Bathroom tub Hand/skin W Kitchen sink Hand W [ Kitchen drain Non hand W Garbage bin Non hand D
Breaking news • Carriage of methicillin-resistant staphylococci by healthy companion animals in US (Davis et al 2014 Lttrs in Appl Micro) • Are community environmental surfaces near hospitals reservoirs for gram- negative nosocomial pathogens? (Rose et al AJIC April 2014)
Conclusions • Complex indoor environments • At risk populations • Community-based infections • Pathogens survive on, and transmitted to/from surfaces, especially high touch surfaces • Merits further studies • Implications for where to focus our efforts to interrupt chain of transmission: hands and high touch surfaces. • Evidence-based hygiene practices
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