Healthcare and Aged Care

By Shital Sarah Ahaley, Medical writer – B.Sc. Microbiology, M.Sc. Microbiology, Ph.D. Developmental Biology.

Surfaces in Healthcare and Aged Care facilities have a high likelihood of being contaminated with infectious bacteria and viruses and are a serious threat to public health. Particularly, high-touch surfaces that can become contaminated easily and may cause rapid transmission of infection.

According to the Australian Government Department of Health, contaminated surfaces are one of the most common transmission methods for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for coronavirus disease 2019 (COVID-19). SARS-CoV-2 can remain on inanimate surfaces for up to 9 days but can be efficiently inactivated by standard surface decontamination methods.1 Other infections agents also persist on frequently touched surfaces.2

Most facilities employ traditional disinfection methods that are short-acting and require repeated application. Furthermore, their effectiveness depends on the efficiency of the individual applying these disinfectants. Lei et al. emphatically state that “The commonly repeated advice to “wash hands frequently” may be replaced in future by more strategic advice such as “clean surfaces right now”, or advice based on who should wash their hands, and when.”2

Hence, there is a need for new products providing efficient and durable surface disinfection; the “clean surfaces right now” strategy.

Titanium Dioxide and Silver Surface Coatings

Self-cleaning antimicrobial photocatalytic surfaces can inactivate microbes under normal ambient lighting conditions. Surface coatings containing titanium dioxide (TiO2) nanoparticles inactivate microbes by producing highly oxidizing free radicals after illumination with visible light or UV light. The free radicals oxidize essential bacterial and viral components thereby killing them.3 The addition of silver (Ag) nanoparticles to this coating further enhance its potency.4

Photocatalytic surface coating:

  • contains TiO2 and Ag as active compounds
  • has strong, broad-spectrum, antiviral, antifungal, and antibacterial effects — kills 99.99% of microbes
  • utilizes an innovative self-cleaning, self-sanitizing technology
  • provides unrivalled stability, allowing for prolonged maintenance of pathogen-free surfaces and objects
  • is environmentally friendly, safe, and 100% biodegradable
  • is non-toxic and non-genotoxic
  • is alcohol and chlorine-free
  • is odour, colour, and taste-free
  • provides professional disinfection for a wide range of domestic and industrial applications — perfect for all human contact surfaces.

Table 1. Comparison of traditional disinfection methods with Antimicrobial surface coatings.

Traditional disinfection methodsAntimicrobial Ti02/Ag surface coating
Contains alcohol, detergents, bleach, and other chemical agentsContains TiO2 and Ag nanoparticles
Short-actingProlonged (up to 2 years)
Erratic and intermittentContinuous and consistent
Effectiveness depends on the person applying the disinfectantSurfaces coated by a trained and experienced professional
Some chemicals are toxicNon-toxic and non-genotoxic
Not possible to clean all contact surfaces with harsh chemicalsPerfect for all contact surfaces
Difficult to clean hard-to-reach surfacesHard-to-reach surfaces covered by the surface coating

Healthcare Effectiveness of Ti02 Photocatalytic Surface Coatings

Laboratory SARS-CoV-2 inactivation experiments have shown that tiles coated with TiO2 inactivate SARS-CoV-2 after 20 minutes of illumination. The authors of this study infer that SARS-CoV-2 is inactivated almost immediately after coming in contact with the surface under ambient indoor lighting.5

TiO2 can inactivate bacteria, viruses, fungi, algae, protozoa, and bacterial toxins too.6

The use of photocatalytic surface coating at Budd Terrace, Emory healthcare, a specialized nursing facility (Atlanta, GA, USA), significantly decreased the rate of infections by 30% over 17 months.7

The efficacy of TiO2 photocatalyst antimicrobial coating was studied in the medical intensive care unit (ICU) of a secondary care teaching hospital in Gyeonggi-do, South Korea. There was a 63% reduced risk of acquiring a methicillin-resistant Staphylococcus aureus (MRSA) infection and a 54% reduced risk of contracting hospital-acquired pneumonia.8

The effect of a photocatalytic antimicrobial coating at near-patient, high-touch sites in an acute-care ward was studied in a large acute-care hospital. A ward with antimicrobial coating was compared with an untreated ward. The microbial burden on surfaces reduced due to photocatalytic coatings. Hygiene failures, indicated by bacterial growth, increased 2.6% per day for untreated surfaces and declined 2.5% per day for treated surfaces over 12 weeks of the study period. The treated surfaces were “cleaner” (more germ free) than untreated surfaces.9

Another study performed in two large hospitals in the U.S. investigated the impact of an antimicrobial surface coating on healthcare-associated infections and microbial burdens over a period of 12 months. The conclusion of the study highlighted a 36% reduction in healthcare-associated infections and reduction of the microbial burden by 75 to 79%.10

Thus, clinical evidence suggests that antimicrobial surface coating can potentially improve patient outcomes and reduce bacterial and viral cross-contamination. This will have a significant impact in the healthcare and aged care sector.

Health and Safety

TiO2 nanoparticles are used in cosmetics like sunscreens, day creams, foundations, and lip balms. TiO2 nanoparticles do not penetrate the skin and are non-carcinogenic, non-mutagenic, and non-teratogenic after skin exposure.

Moreover, accidental oral exposure to nano-TiO2 does not cause adverse health effects. In fact, TiO2 is approved by the European Union authorities to be used as a food colourant.11

The Scientific Committee on Consumer Safety (SCCS) does not recommend lung exposure via inhalation as it may cause lung inflammation.12 However, after the application of surface coatings, there is no risk of inhalation. Thus, it can be concluded that TiO2 surface coatings are safe and do not pose a health risk.

Healthcare and Aged Care Cost Effectiveness

Australia does not have national surveillance for healthcare-associated infections. Therefore, the effects of national infection prevention initiatives cannot be assessed.13 It is predicted that healthcare-associated infections may be approximately 165,000 per year.14

They comprise a public health problem and lead to increased healthcare costs.

Though there are no estimates of the economic burden due to healthcare-associated infections, estimates for antimicrobial resistant infections can give a general idea. The additional burden of treating ceftriaxone-resistant E. coli bloodstream infections in Australian hospitals is AUD$5.8 million per year and the estimated cost of treating MRSA infections is AUD$5.5 million per year.15

These costs can be effectively reduced by implementing measures to prevent healthcare-associated infections.

Several risk factors contribute to the prevalence of healthcare-associated infections. The risk of contamination from contact with surfaces and medical devices may be responsible for several healthcare-associated infections.

Conclusion

Healthcare and Aged Care facilities represent the most high-risk public places for the spread of diseases.

Moreover, the most vulnerable population is also present in these facilities. There is a high risk of infection due to exposure to contaminated surfaces. Chemical decontamination with traditional disinfection methods lacks durability and consistent efficiency.

Self-cleaning, self-sanitising TiO2 photocatalytic surfaces are safe, cost-effective and highly efficient in killing microbes.

Titanium dioxide and silver surface coatings yield self-cleaning antimicrobial photocatalytic surfaces that will effectively help reduce the microbial burden and cross-infection possibilities within the Healthcare and Aged Care sectors.

References:
  1. Kampf G, Todt D, Pfaender S, Steinmann E. Persistence of coronaviruses on inanimate surfaces and their inactivation with biocidal agents. J Hosp Infect. 2020;104(3):246-251. doi:https://doi.org/10.1016/j.jhin.2020.01.022.
  2. Lei H, Li Y, Xiao S, et al. Logistic growth of a surface contamination network and its role in disease spread. Sci Rep. 2017;7(1):14826. doi:10.1038/s41598-017-13840-z.
  3. Dicastillo CL de. Antimicrobial Effect of Titanium Dioxide Nanoparticles. In: Correa MG, ed. Rijeka: IntechOpen; 2021:Ch. 5. doi:10.5772/intechopen.90891.
  4. Soo JZ, Chai LC, Ang BC, Ong BH. Enhancing the Antibacterial Performance of Titanium Dioxide Nanofibers by Coating with Silver Nanoparticles. ACS Appl Nano Mater. 2020;3(6):5743-5751. doi:10.1021/acsanm.0c00925.
  5. Micochova P, Chadha A, Hesseloj T, Fraternali F, Ramsden JJ, Gupta RK. Rapid inactivation of SARS-CoV-2 by titanium dioxide surface coating [version 2; peer review: 2 approved]. Wellcome Open Res. 2021;6(56). doi:10.12688/wellcomeopenres.16577.2.
  6. Foster HA, Ditta IB, Varghese S, Steele A. Photocatalytic disinfection using titanium dioxide: spectrum and mechanism of antimicrobial activity. Appl Microbiol Biotechnol. 2011;90(6):1847-1868. doi:10.1007/s00253-011-3213-7.
  7. Pulliam JR. Lower infection rates after introduction of a photocatalytic surface coating. Am J Infect Control. 2015;43(2):180-181. doi:https://doi.org/10.1016/j.ajic.2014.10.023.
  8. Kim MH, Lee SG, Kim KS, Heo YJ, Oh JE, Jeong SJ. Environmental disinfection with photocatalyst as an adjunctive measure to control transmission of methicillin-resistant Staphylococcus aureus: a prospective cohort study in a high-incidence setting. BMC Infect Dis. 2018;18(1):610. doi:10.1186/s12879-018-3555-1.
  9. Reid M, Whatley V, Spooner E, et al. How Does a Photocatalytic Antimicrobial Coating Affect Environmental Bioburden in Hospitals? Infect Control Hosp Epidemiol. 2018;39(4):398-404. doi:10.1017/ice.2017.297.
  10. Ellingson KD, Pogreba-Brown K, Gerba CP, Elliott SP. Impact of a Novel Antimicrobial Surface Coating on Health Care–Associated Infections and Environmental Bioburden at 2 Urban Hospitals. Clin Infect Dis. 2020;71(8):1807-1813. doi:10.1093/cid/ciz1077.
  11. Ziental D, Czarczynska-Goslinska B, Mlynarczyk DT, et al. Titanium Dioxide Nanoparticles: Prospects and Applications in Medicine. Nanomater (Basel, Switzerland). 2020;10(2):387. doi:10.3390/nano10020387.
  12. Dréno B, Alexis A, Chuberre B, Marinovich M. Safety of titanium dioxide nanoparticles in cosmetics. J Eur Acad Dermatol Venereol. 2019;33 Suppl 7:34-46. doi:10.1111/jdv.15943.
  13. Russo PL, Cheng AC, Mitchell BG, Hall L. Healthcare-associated infections in Australia: tackling the “known unknowns.” Aust Heal Rev. 2018;42(2):178-180.
  14. Mitchell BG, Shaban RZ, MacBeth D, Wood C-J, Russo PL. The burden of healthcare-associated infection in Australian hospitals: A systematic review of the literature. Infect Dis Heal. 2017;22(3):117-128. doi:https://doi.org/10.1016/j.idh.2017.07.001.
  15. Wozniak TM, Bailey EJ, Graves N. Health and economic burden of antimicrobial-resistant infections in Australian hospitals: a population-based model. Infect Control Hosp Epidemiol. 2019;40(3):320-327. doi:DOI: 10.1017/ice.2019.2.
  16. Dunlop PSM, Sheeran CP, Byrne JA, McMahon MAS, Boyle MA, McGuigan KG. Inactivation of clinically relevant pathogens by photocatalytic coatings. J Photochem Photobiol A Chem. 2010;216(2):303-310. doi:https://doi.org/10.1016/j.jphotochem.2010.07.004.
  17. Margarucci LM, Romano Spica V, Protano C, et al. Potential antimicrobial effects of photocatalytic nanothecnologies in hospital settings. Ann Ig. 2019;31(5):461-473. doi:10.7416/ai.2019.2307.

This article has been commissioned for publication by CleanShield Australia – Surface Coating division.

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Aged CareAntimicrobial surface coatingbroad-spectrumhealthcareHospital patientsSARS-CoV-2self-cleaningself-sanitizingSurface CoatingTi02 Photocatalytic Surface Coatings
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