Research on Environmental Hygiene: An Overview

The information on this page is updated as new research is published. This page was last updated on 20 February 2020.

The current focus for hygiene research is on the healthcare environment, including personnel, and how it contributes to the transmission of healthcare-acquired infections (HAIs), a common and mostly preventable patient safety issue. This is due to a pattern of findings within the research that highlight:

  • high levels of contamination are present in healthcare settings1; and
  • if a patient with a multi-drug resistant organism previously occupied a room, despite terminal cleaning, the next patient was still at increased risk of acquiring that illness1.

Although it is not yet established how clean surfaces must be in order to prevent the transmission of HAIs1, preliminary research has investigated the levels of contamination and whether implementing various interventions may contribute to a reduction in colony counts after certain time periods.

The most common interventions have been education, monitoring and cleaning intensity. One study found that it would take one additional full-time staff member whose role solely focused on high-touch surfaces to significantly reduce the rates of MRSA in a hospital setting1.

While research in the area of environmental contamination is relatively new, data has been collated to demonstrate the level of contamination, particularly within hospital settings. Schabrun (2006)2 reports that over 70% of equipment is contaminated while Dancer (2014)3 found that screening confirms repeated contamination of items, equipment, and general sites in bed spaces and rooms of infected patients and often throughout multiple clinical areas in a healthcare institution.

Interestingly, equipment in less critical areas, such as general wards, outpatients or allied health departments, are less likely to have stringent cleaning protocols, predisposing these departments to carrying larger numbers of microorganisms2.Further, several studies show evidence of the ability for bacteria to survive from days to weeks on inanimate objects (MRSA was found to survive nine weeks)4 underscoring the importance of environmental hygiene in the control of infection and cross-transmission4, 5.

It has also been shown that merely touching a contaminated surface can result in the same frequency of MRSA contamination as touching the infected patient5 reiterating the need for increased measures in protection, such as protective barriers and stringency in cleaning protocol.

A 2016 study of Australian hospitals found a great discrepancy between cleaning practices among facilities and wards, despite detailed guidelines, leading to subjective standards of cleanliness across facilities6. With varying resources, general standards, protocol adherence and monitoring, it is extremely difficult to establish a baseline against which all facilities can be measured, nor can a general program be easily rolled out to address any issues. There have been several studies which have examined the efficacy of particular interventions.

One such study examined the effectiveness of a trio of strategies such as ‘hygiene bundles’, ongoing education and stricter monitoring of hygiene protocol; while successful short term, replication and maintenance in the “real world” was not sustainable due to inadequate training, skill level of workers, as well as general non-compliance to the prescribed protocol7. Otter et al (2013)8 reported that hospital hand hygiene compliance was significantly more likely following patient contact as opposed to patient environment contact, meaning any transfer of contaminants was likely to persist for longer and play a more significant role in forward transmission of disease.

In terms of effective cleaning measures, 70% alcohol was found to be the most effective agent with up to 80% reduction of contamination2. However, it is unknown how this agent will affect the quality of the equipment and fabrics in the long term. Another major drawback in the use of these cleaning agents, is the gap between the recommended instructions and real life application and use. Adherence to correct cleaning protocol is not closely monitored, and many infection prevention institutions provide ‘guidelines’ to ensure adherence which primarily use a subjective visibility scale to determine cleanliness.  Additionally, it has been established that some illness causing bacteria persist despite more than one cycle of cleaning using hospital grade disinfectant9; 27% of rooms remained contaminated with MRSA following 4 rounds of bleach disinfection. Similarly, 43% of surfaces were contaminated with norovirus RNA after 1 round of bleach disinfection, and 16% of surfaces were contaminated after 2 rounds of bleach disinfection8.

With the use of towels, studies have demonstrated that the more absorbent a towel, the longer a microorganism can survive10. In particular, it was shown that Staph can survive up to three weeks in cotton towels – which are commonly used in therapy clinics and hospitals - despite regular laundering10. It was concluded that normal washing, or laundering of towels – whether done in house or externally, was not enough to remove all viable microorganisms from them10.

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  1. Doll, M., Stevens, M., Bearman, G., Environmental Cleaning and Disinfection of Patient Areas. International Journal of Infectious Diseases 67:52-57(2018);
  1. Schabrun, S., Chipchase, L., Healthcare equipment as a source of nosocomial infection: a systematic review. Journal of Hospital Infection 63(3): 239-245 (2006);
  1. Dancer, S. Controlling Hospital-Acquired Infection: Focus on the Role of the Environment and New Technologies for Decontamination. Clinical Microbiology Reviews 27 (4):665-690 (2014) DOI:1128/CMR.00020-14
  1. Hota, B. Contamination, Disinfection, and Cross-Colonization: Are Hospital Surfaces Reservoirs for Nosocomial Infection? Healthcare Epidemiology 39: 1182-9 (2004) DOI:1086/424667
  1. Weber, D J. Anderson, Dc; Rutala, W. the role of the surface environmentin healthcare-associated infections.Current Opinion in Infectious Diseases (2013) 26:338–344 DOI:10.1097/QCO.0b013e3283630f04
  1. Hall, L., Farringont, A., Mitchell, BG., et al. Researching effective approaches to cleaning in hospitals: protocol of the REACH study, a multi-site stepped-wedge randomised trial. Implement Sci.2016 Mar 24;11:44. doi: 10.1186/s13012-016-0406-6.
  1. Popalyar, A,, Stafford, J., Ogunremi, T., Dunn, K.. Infection prevention in personal services settings: Evidence, gaps and the way forward. Can Commun Dis Rep.2019 Jan 3;45(1):1-11. doi: 10.14745/ccdr.v45i01a01.
  1. Otter, J A. et al. Evidence that contaminated surfaces contribute to the transmission of hospital pathogens and an overview of strategies to address contaminated surfaces in hospital settings. American Journal of Infection Control, (2013) Volume 41, Issue 5, S6 - S11
  1. Almatroudi, A., Gosbell, IB., Hua, H., et al. Staphylococcus aureus dry-surface biofilms are not killed by sodium hypochlorite: implications for infection control. Journal of Hospital Infections.2016 Jul;93(3):263-70. doi: 10.1016/j.jhin.2016.03.020. Epub 2016 Apr 12.
  1. Sifuentes, LY., Gerba, CP, Weart, I., Engelbrecht, K., Koenig, DW. Microbial contamination of hospital reusable cleaning towels. American Journal of Infection Control. 2013 Oct;41(10):912-5. doi: 10.1016/j.ajic.2013.01.015. Epub 2013 Mar 22.